Report on Groundwater Recharge in the Orange County Groundwater Basin

Transcription

1 29-21 Report on Groundwater Recharge in the Orange County Groundwater Basin

2 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Orange County Water District August 211 Prepared by: Chris McConaughy, Chief Recharge System Operator John Vandenberg, Recharge System Operator Adam Hutchinson, Director of Recharge Operations

3 Cover Photo Location: Close up of ducks on the Santa Ana River Cover Photo Credit: Angela A. Stanton Stanton Photo Studios

4 Table of Contents Page Executive Summary 1 Section 1. Introduction 3 2. Background 3 3. Recharge Water Sources Precipitation Santa Ana River Santiago Creek Imported and Purchased Water Recycled Water Water Losses Surface Water Recharge Operations Overview Santa Ana River Channel Weir Ponds 1-4 (Desilting System) Warner Basin System Anaheim Lake Mini-Anaheim Lake Kraemer Basin Miller Basin La Jolla Basin Placentia Basin Raymond Basin Off-River Channel Olive Basin Five Coves Basins Lincoln Basin Burris Basin River View Basin Santiago Basins Santiago Creek Channel Seawater Barrier Recharge Talbert Gap Seawater Barrier Alamitos Gap Seawater Barrier In-Lieu Recharge Recharge Summary Recharge Sources Recharge Facilities References 49

5 List of Tables Page ES-1 Recharge Source Summary Area and Storage Capacity of Surface Water Recharge Facilities Monthly Recharge in Santa Ana River Channel, Monthly Recharge in Weir Pond 3, Monthly Recharge in Warner Basin System, Monthly Recharge in Anaheim Lake, Monthly Recharge in Mini-Anaheim Lake, Monthly Recharge in Kraemer Basin, Monthly Recharge in Miller Basin, Monthly Recharge in La Jolla Basin, Monthly Recharge in Placentia Basin, Monthly Recharge in Raymond Basin, Monthly Recharge in Off-River Channel, Monthly Recharge in Olive Basin Monthly Recharge in Five Coves Basins, Monthly Recharge in Burris Basin, Monthly Recharge in River View Basin, Monthly Recharge in Santiago Basins, Monthly Recharge in Santiago Creek Channel, Recharge Source Summary Recharge Facility Summary 48 List of Figures Page ES-1 Total Annual Recharge by Source, OCWD Location Map Surface Water Recharge Facilities Annual Rainfall Totals at OCWD Field Headquarters, Monthly Rainfall Totals at OCWD Field Headquarters, Annual Incidental Recharge, Monthly Local Storm Flow Capture, Annual Base and Storm Flow in the SAR at Prado Dam, Monthly Santa Ana River Base and Storm Flow Recharged, Prado Water Conservation Pool Storage, Monthly Captured Storm Flow from Santiago Creek, Monthly Recharge of Imported and Purchased Water, Monthly Recharge of Recycled Water, Monthly Recharge System Losses,

6 List of Figures (Cont d) Page 5-1 Talbert Gap Seawater Barrier Annual Injection at the Talbert Barrier, Alamitos Gap Seawater Barrier Annual Injection at the Alamitos Barrier, Annual In-Lieu Recharge, Total Monthly Recharge by Source, Recharge Sources, Total Annual Recharge by Source, Recharge by Facility, Total Annual Recharge by Facility, Appendices Appendix A Acronyms/Definitions Appendix B: Data Tables Description of Data Sources Table B-1 Monthly Rainfall at OCWD Field Headquarters, Table B-2 Annual Incidental Recharge, 2-21 Table B-3 Monthly Local Inflow Summary, 29-1 Table B-4 Annual SAR Watermaster Base Flow and Storm Flow, Table B-5 Monthly SAR Base Flow and Storm Flow Recharged, 29-1 Table B-6 Monthly Santiago Creek Inflow, 29-1 Table B-7 Monthly Recharge of Imported and Purchased Water, 29-1 Table B-8 Monthly Recharge of Recycled Water, 29-1 Table B-9 Monthly Losses to Ocean and Evaporation, 29-1 Table B-1 Annual Injection for Talbert Barrier, Table B-11 Monthly Injection for Talbert Barrier, 29-1 Table B-12 Annual Injection for Alamitos Barrier, Table B-13 Monthly Injection for Alamitos Barrier, 29-1 Table B-14 Annual In-Lieu Recharge of Imported Water, Table B-15 Monthly In-Lieu Recharge of Imported Water, 29-1 Table B-16 Annual Recharge by Source, 2-21 Table B-17 Monthly Recharge Source Summary, 29-1 Table B-18 Annual Recharge by Facility, 2-21 Appendix C: Monthly Forebay Percolation Efficiency Reports

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8 Executive Summary A total of inches of rain was received at the District s Anaheim Field Headquarters in 29-1 (OCWD fiscal year ending June 3), which is approximately 2 percent above the historical average of 14.4 inches and broke a string of four consecutive years of below average rainfall. The above average rainfall also resulted in above average storm flow and above average incidental (unmeasured) recharge. Since 24-5, Santa Ana River base flows have declined over 33 percent; however, flows appear to have leveled off with the 29-1 flow of 12,599 acre-feet only 3, acre-feet less than the 28-9 flow (15,49 acre-feet). Compared to the last 1 years, Santa Ana River base flow recharge in 29-1 is 24 percent below average. Imported water recharge was 69 percent below the 1-year average due to the continued unavailability of discounted replenishment water and lack of water available for in-lieu recharge. The District was able to recharge a total of 21,586 acre-feet of imported water, with much of it being full service untreated water recharged in the surface water recharge system. The Groundwater Replenishment System (GWR System) provided 65,95 acre-feet of recycled water to the surface water and seawater barrier recharge systems, which represents a historic high for recycled water recharged to the basin. Seawater barrier recharge in 29-1 reached an all time high and was more than double the 1-year average. In total, recycled water provided 2 percent of water recharged to the basin in Total recharge to the groundwater basin in 29-1 equaled 334,965 acre-feet, which is only one percent below the 1-year average of 338,995 acre-feet per year. The increased capture of storm flow, above-average incidental recharge and large increase in recycled water recharge largely offset reduced Santa Ana River base flows and reduced imported water supplies. Table ES-1 and Figure ES-1 show how 29-1 recharge compares to the previous 1 years. Source Table ES-1 Recharge Source Summary FY9-1 (af) 1-Year Avg (af) Increase/ (Decrease) (af) % Increase/ (Decrease) SAR Base Flow (1) 12, ,699 (33,1) (24) Storm Flow/Local Water (2) 61,35 52,339 8, Imported/Purchased Water 21,586 7,498 (48,912) (69) Groundwater (3) 2,968 (2,968) (1) Recycled Water 66,56 15,961 5, Total OCWD Recharge (4) 251, ,465 (25,739) (9) Incidental Recharge 83,239 61,53 21,79 35 Grand Total 334, ,995 (4,3) (1) (1) SAR Base Flow based on OCWD data, which may differ slightly from the SAR Watermaster (see Section 3.2). (2) Storm flow includes SAR storm flow and local inflow to the recharge system below Prado Dam. (3) Groundwater was used to augment the injection supply at the Talbert Barrier until July 26. (4) Recharge at all OCWD facilities. 1

9 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Annual Recharge (af) 6, 5, 4, 3, 2, Incidental Recharge Groundwater Recycled Water Imported/Purchased Water Storm Flow/Local Water SAR Base Flow Avg. 339, afy 1, Fiscal Year Figure ES-1 Total Annual Recharge by Source,

10 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Section 1 Introduction The Orange County Water District (OCWD or District) was formed by a special act of the California Legislature in 1933 for the purpose of managing and protecting the Orange County groundwater basin. Since its formation, the District has developed a successful aquifer recharge system that has doubled the yield of the groundwater basin. Aquifer recharge activities conducted by OCWD fall into three categories: 1) Surface Water Recharge, 3) Seawater Barrier Recharge, 3) and In-Lieu Recharge. Naturally occurring recharge to the basin, called incidental recharge, rounds out the sources of recharge to the groundwater basin. For completeness, incidental recharge estimates are presented in this report along with aquifer recharge resulting from District activities. The purpose of this report is to present a breakdown of the water sources used to recharge the basin and which facilities were used to recharge these waters. The focus of this report is OCWD fiscal year 29-1 (July 1, 29 - June 3, 21); however, historical data are provided where appropriate to provide a context for 29-1 results. Unless otherwise noted, all volumes in this report are for the OCWD fiscal year. Acronyms are presented in Appendix A. Appendix B presents the data used to prepare this report along with a description of the data sources. Appendix C contains 29-1 Monthly Forebay Percolation Efficiency Reports prepared by Recharge Operations staff, which presents monthly performance data for the surface recharge facilities operated by the District. Section 2 Background The Orange County groundwater basin underlies the north half of Orange County and covers approximately 35 square miles (see Figure 2-1). The aquifers comprising the Orange County groundwater basin extend over 2, feet deep and form a complex series of interconnected sand and gravel deposits (DWR, 1967). In coastal and central portions of the basin, these deposits tend to be separated by extensive lower-permeability clay and silt deposits, known as aquitards (Pressure area). In the inland area of the basin, generally northeast of Interstate 5, the clay and silt deposits become thinner and more discontinuous, allowing groundwater to flow more easily between shallow and deeper aquifers (Forebay). Shortly after the District was formed in 1933, the District, along with the Orange County Flood Control District (OCFCD), began experimenting with ways to increase the percolation capacity of the Santa Ana River (SAR) channel. These experiments included removing vegetation and re-sculpting the river bank and river bottom (OCWD, 23a). Based on the success of these experiments, the District began purchasing portions of the SAR channel as they became available. In 1936 the District made its first purchase of 26 acres of the SAR channel for $722. The District eventually acquired six miles of the SAR channel extending from Imperial Highway (SR9) to Ball Road, as shown on Figure

11 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Currently the District owns over 1,5 acres of land in the Forebay on which it has constructed approximately two dozen recharge facilities that cover nearly 1, wetted acres (OCWD, 23a; OCWD, 23b) (see Figure 2-2). In addition, the District utilizes several flood control basins owned by the OCFCD for recharge. Along with land purchases, the District invested heavily in infrastructure to maximize the ability of the facilities to recharge water, including four rubber dams, over six miles of pipelines, eight pump stations, and a fleet of earthmoving equipment. Near the coast, seawater intrusion can occur in gaps in the Newport-Inglewood Fault zone. The fault zone is effective in preventing seawater intrusion into the Orange County groundwater basin except in the Alamitos and Talbert Gaps. The gaps are erosional features cut by rivers that deposited permeable sediments, creating pathways for seawater to bypass the fault zone and enter groundwater basin aquifers. To minimize seawater intrusion, the Alamitos Barrier was designed and constructed in 1965 (see Figure 2-1). The Los Angeles County Department of Public Works (LACDPW) operates and maintains Alamitos Barrier facilities under the direction and approval of the Alamitos Barrier Joint Management Committee, whose membership covers five agencies including OCWD. The Talbert Barrier was constructed by OCWD and went on-line in the mid-197s. The Alamitos 4

12 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Barrier currently contains 43 injection wells while the Talbert Barrier contains 36 injection wells. Additional injection wells are continually being added as new information about the extent of seawater intrusion becomes available. In addition to surface water recharge and seawater injection barriers, the District recharges the basin via in-lieu recharge. In-lieu recharge occurs when groundwater producers take imported water in-lieu of pumping groundwater. By turning off wells, the process indirectly recharges the groundwater basin. This program was established by the Metropolitan Water District of Southern California (MWD) in and has been used extensively since then by the District. This type of recharge is effective because it allows for recharge in areas distant from surface water or injection recharge facilities and it frees up capacity in the surface water recharge system for SAR and other sources of water. 5

13 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Section 3 Recharge Water Sources This section presents a summary of the sources of water used to recharge the groundwater basin. 3.1 Precipitation The Orange County groundwater basin is located in a semi-arid region. At OCWD s Field Headquarters rain gauge in east Anaheim, the average annual rainfall for the entire period of record from is inches. In 29-1, a total of inches of rain was recorded, which is approximately 2 percent above the historical average. The maximum amount of rainfall of inches was recorded in 24-5 and the minimum of 2.53 inches was recorded in Figure 3-1 shows the annual historical rainfall at this location. Figure 3-2 shows the monthly rainfall received at OCWD Field Headquarters in Table B-1 in Appendix B presents the data used to prepare these graphs Annual Rainfall (inches) Average ( ): inches Fiscal Year (July-June) Figure 3-1 Annual Rainfall Totals at OCWD Field Headquarters, Rain that falls within the District boundary results in storm flow and incidental recharge. Incidental recharge, which is not directly measured, tends to be widespread over the basin and consists of recharge from hills and mountains adjacent to the groundwater basin, 6

14 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 8 7 Total: inches 7.12 Monthly Rainfall (inches) Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 3-2 Monthly Rainfall Totals at OCWD Field Headquarters, 29-1 underflow beneath the SAR and Santiago Creek, areal recharge from precipitation, irrigation return flows, and urban runoff (OCWD, 24; OCWD, 27). Incidental recharge reported herein is net recharge to the basin after losses to Los Angeles County are subtracted from total incidental recharge. The estimated volume of incidental recharge correlates with local rainfall totals. For example, in 24-5, when a record inches of rain was received at Field Headquarters, estimated incidental recharge totaled 158,733 acre-feet. For 26-7, a record dry year, estimated incidental recharge totaled 14,172 acre-feet. For years with average rainfall, incidental recharge is estimated to be approximately 6, acre-feet. Figure 3-3 shows the annual estimated incidental recharge to the groundwater basin for the last 1 years. Table B-2 in Appendix B presents estimated incidental recharge for 2 to 21. Precipitation that falls within the SAR watershed below Prado Dam and in the Santiago Creek watershed produces locally derived storm flow. Much of this water is captured and recharged; however, storm flow that enters the SAR channel downstream of the District s recharge facilities is essentially lost to the ocean. During periods of no rainfall, locally derived flows, such as nuisance water, are also captured and recharged. For simplicity, all locally derived flows are categorized as storm flow regardless of the time of year the flows were generated. 7

15 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 18, 16, Annual Incidental Recharge (af) 14, 12, 1, 8, 6, 4, Avg. 61,53 afy 2, Fiscal Year (July-June) Figure 3-3 Annual Incidental Recharge, 2-21 In 29-1, an estimated 6,594 acre-feet of local storm flow was captured and recharged by the surface water recharge system. This does not include SAR storm flow arriving at Prado Dam (see next section). Figure 3-4 shows the monthly volume of local storm flow provided to the recharge system in Table B-3 in Appendix B presents the data used to prepare this graph. 3.2 Santa Ana River The SAR is the largest source of water to the surface water recharge system. In response to development in the upper SAR watershed, SAR base flow increased from the late 197s to late 199s (Figure 3-5). In the past 1 years, however, due to conservation and other factors, SAR base flow, which is comprised primarily of treated wastewater, has declined over 33 percent. Urbanization of the watershed has also affected storm flow runoff, with more flow arriving at Prado Dam for a given amount of rain (Warrick and Rubin, 27). Figure 3-5 shows the total annual Oct.-Sept. water year base flow and storm flow that has flowed past Prado Dam since Table B-4 in Appendix B presents base flow and storm flow data for the SAR from 1936 to 21. 8

16 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 4, 3,5 Direct Rainfall to Recharge Basins Local Storm Flow to Santiago Basins Local Storm Flow to SAR Below Imperial Rubber Dam 3, Monthly Local Inflow (af) 2,5 2, 1,5 1, 5 Jul-9 Aug-9 Sep-9 Oct-9 *Assumes direct rainfall to 5 acres of recharge basins. Nov-9 Dec-9 Month Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Figure 3-4 Monthly Local Storm Flow Capture, 29-1 Annual SAR Flow at Prado Dam* (af) 7, 6, 5, 4, 3, 2, 1, SAR Storm Flow SAR Base Flow Oct. - Sept. Water Year *Source:SAR Watermaster Reports Figure 3-5 Annual Base and Storm Flow in the SAR at Prado Dam,

17 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin It is assumed that the surface water recharge system captures and recharges all SAR base flow. However, the volume of SAR storm flow captured and recharged varies and is highly dependent on the distribution of rainfall during the winter months and the operation of the Prado Dam water conservation pool (discussed in the next section). OCWD data are used to determine the total flow of SAR water reaching the recharge system in order to account for local inflows that occur below Prado Dam. As a result, what is reported in this document may differ slightly from what is reported by the SAR Watermaster. In addition, there may be differences in monthly volumes of SAR storm flow because the SAR Watermaster accounts for storage behind Prado Dam. SAR Watermaster data, which are based on measurements made by the United States Geological Survey (USGS), are used when OCWD s gauges and flow meters are not operating and during the storm season to define the base flow component SAR flows. For 29-1, a total of 12,599 acre-feet of SAR base flow and 54,441 acre-feet of SAR storm flow were captured and recharged. Figure 3-6 shows the monthly variation in recharged SAR base flow and storm flow for Table B-5 in Appendix B presents the data used to prepare this graph. 25, SAR Storm Flow SAR Base Flow Monthly SAR Flow Recharged (af) 2, 15, 1, 5, - Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 3-6 Monthly Santa Ana River Base and Storm Flow Recharged,

18 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Prado Dam Water Conservation Pool Through an agreement with the US Army Corps of Engineers (USACOE), OCWD is allowed to conserve storm flows captured behind Prado Dam. The Prado Dam conservation pool allows for capture and storage of multiple storm events with a maximum of 9,278 acre-feet of storage during the flood season (Oct. 1-Feb. 28) and up to 19,826 acre-feet of storage during the non-flood season (March 1 to Sept. 3) (USACOE, 1994; USFWS, 2; USACOE, 22). Generally, releases of water by the USACOE from the conservation pool are coordinated with the District to minimize losses to the ocean. In the past, the reported volumes of water that could be captured in the conservation pools were greater, but a new survey of the Prado Basin conducted in 28 showed that sediment accumulation behind the dam has significantly reduced conservation pool volumes since the last survey was conducted in In 29-1, an estimated total of 25,6 acre-feet of storm flow was captured in the conservation pool and subsequently recharged. Heavy rain in January and February resulted in a large volume of water captured behind the dam, but any water above the allowable storage level of 9,278 acre-feet (elevation 498 feet above means sea level) was discharged to the ocean. Rain in late February and in March resulted in a portion of the non-flood season conservation pool (after March 1) being utilized. Figure 3-7 shows how storage in the conservation pool varied during , 3, Conservation Pool Storage (af) 25, 2, 15, 1, 5, Max. Conservation Pool Storage (af) Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 3-7 Prado Water Conservation Pool Storage,

19 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 3.3 Santiago Creek Most of the precipitation that falls in the Santiago Creek watershed results in runoff that is captured behind Santiago and Villa Park Dams. Santiago Dam, which creates Irvine Lake, is owned by the Irvine Ranch and Serrano Water Districts. Villa Park Dam is primarily a flood control dam that is owned and operated by the OCFCD. Precipitation that falls within the approximately 5.5 square mile catchment area that drains the area below Villa Park Dam ends up flowing down Santiago Creek into the District s Santiago Basins. Periodically stored water is released from Villa Park Dam to Santiago Basins to allow the OCFCD to conduct maintenance on the dam. In 29-1, an estimated 3,27 acre-feet of storm flow to Santiago Basins was received from Santiago Creek. Figure 3-8 shows the monthly estimated contribution of Santiago Creek to recharge in Santiago Basins in A total of 38 acre-feet of stored water was released from Villa Park Dam to the Santiago Basins in February 21. As mentioned previously, all inflow to Santiago Basins is categorized as storm flow including nuisance flows during the summer months. Table B-6 in Appendix B presents the data used to prepare this graph. 2, 1,8 Water Released from Villa Park Dam Santiago Creek Storm Flow Monthly Santiago Creek Inflow (af) 1,6 1,4 1,2 1, Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 3-8 Monthly Captured Storm Flow from Santiago Creek,

20 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 3.4 Imported and Purchased Water Imported water, which is purchased for recharge from MWD, comes from the either the Colorado River Aqueduct (CRA) or the State Water Project (SWP). Raw, untreated MWD water can be delivered to the surface water recharge system in multiple locations, including Anaheim Lake (OC-28/28A), Santa Ana River (OC-11), Irvine Lake (OC-13), and San Antonio Creek near the City of Upland (OC-59). Connections OC-28, OC-11 and OC-13 supply OCWD with CRA water. Connection OC-59 supplies OCWD with SWP water and OC-28A supplies OCWD with a variable blend of CRA and SWP water. Treated MWD water is purchased for recharge from various other MWD connections for use at the seawater barriers and for in-lieu recharge. In recent years, water has also been purchased from within the SAR watershed from Western Municipal Water District (WMWD) and San Bernardino Valley Municipal Water District (SBVMWD). Water purchased from WMWD includes treated groundwater produced by the Arlington Desalter and groundwater from Elsinore Valley Municipal Water District wells. Both sources of water from WMWD are discharged to the SAR upstream of Prado Dam. Water purchased from the SBVMWD is groundwater, which is also pumped and discharged to the SAR. In 29-1, limited supplies of water were available for purchase from MWD for surface water recharge and no water was available for in-lieu recharge. A total of 2,536 acre-feet was purchased for recharge in the surface water recharge system and 943 acre-feet of treated MWD water was purchased for recharge at the Talbert and Alamitos Barriers. A total of 16 acre-feet of water was purchased from WMWD for recharge in the surface water recharge system. Figure 3-9 shows the monthly totals of imported and purchased water recharged in Table B-7 in Appendix B presents the data used to prepare this graph. 3.5 Recycled Water In January 28, the District s Groundwater Replenishment System (GWR System) became operational. This GWR System replaces Water Factory 21 and includes advanced water treatment processes consisting of micro-filtration (MF) followed by reverse osmosis (RO) and ultraviolet (UV) light disinfection in combination with hydrogen peroxide. The plant is designed to treat up to 72, acre-feet per year and deliver this water to the Talbert Barrier and the surface water recharge system, specifically, Kraemer and Miller Basins. To supply water to Kraemer and Miller Basins, a 13-mile pipeline was constructed adjacent to the Santa Ana River from the treatment plant in Fountain Valley to Kraemer and Miller Basins in Anaheim (see Figure 2-2). In 29-1, 36,333 acre-feet of recycled water was recharged in the Talbert Barrier and 29,617 acre-feet was recharged in Kraemer/Miller Basins. 13

21 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Total Monthly Recharge (af) 9, 8, 7, 6, 5, 4, 3, 2, Alamitos Barrier Talbert Barrier MWD In-Lieu (CUP*) OCWD In-Lieu Total Import/Purchased Water Recharged via Surface Water System 1, Jul-9 *Conjunctive Use Program Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Month Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Figure 3-9 Monthly Recharge of Imported and Purchased Water, 29-1 In 29-1, a total of 2,31 acre-feet of recycled water was recharged at the Alamitos Barrier with 556 acre-feet counted as recharge to the Orange County groundwater basin. Recycled water supplied to the Alamitos Barrier is produced by the Leo J. Vander Lans Water Treatment Facility, which is operated by the Long Beach Water Department under contract with the Water Replenishment District of Southern California (WRD). Figure 3-1 shows the monthly totals of recycled water recharged in Table B-8 in Appendix B presents the data used to prepare this graph. 3.6 Water Losses Water losses from the surface water recharge system include flows in the SAR, Santiago Creek and Carbon Creek that flow past the recharge system. The majority of water lost to the recharge system occurs in the SAR channel when flows are in excess of 1, cubic feet per second (cfs) because the rubber dams used to divert water from the channel are typically deflated during periods of high flow. In 29-1, 87,5 acre-feet of SAR water was lost to the ocean, with most of the losses occurring in January and February 21 (Figure 3-11). Another source of water loss is evaporation. For many of the recharge basins, evaporative losses are included in the storage change. No effort is made to estimate evaporative losses 14

22 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 9, 8, 7, Alamitos Barrier Talbert Barrier Surface Water Recharge System 6, 5, 4, 3, 2, 1, Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Monthly Recharge (af) Month Figure 3-1 Monthly Recharge of Recycled Water, 29-1 in the recharge basins because evaporative losses are so minor compared to the recharge volumes involved. For other facilities, such as the SAR channel, evaporative losses are calculated based on evaporation pan readings taken at Field Headquarters. It is assumed that the water surface area is 5 acres, which is approximately half of the recharge system wetted area. Using this approach, it is estimated that approximately 2,572 acre-feet of water was lost to evaporation in 29-1 from these facilities. Figure 3-11 shows the estimated monthly losses to the ocean and evaporation losses in Table B-9 in Appendix B presents the data used to prepare this graph. 15

23 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin 6, 5, Evaporation Losses Losses to Ocean in Carbon Creek Losses to Ocean in Santiago Creek Losses to Ocean in SAR Monthly Losses (af) 4, 3, 2, 1, Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 3-11 Monthly Recharge System Losses,

24 29-1 Report on Groundwater Recharge in the Orange County Groundwater Basin Section 4 Surface Water Recharge This section provides an overview of the surface water recharge system and the volumes and sources of water used for recharge. In addition, the monthly recharge performance of each facility is presented. Recharge performance data are based on monthly Forebay Percolation Efficiency Reports prepared by District Recharge Operations staff. Copies of the Forebay Percolation Efficiency Reports for 29-1 are presented in Appendix C. 4.1 Operations Overview The District s surface water recharge system is currently comprised of 25 facilities which cover over 1, wetted acres and have a storage volume of over 26, acre-feet (see Figure 2-2 for facility locations). Table 4-1 lists the area and storage capacity of each recharge facility. The main source of inflow to the recharge system is the SAR. When SAR flows reach the Imperial Rubber Dam located just downstream of Imperial Highway, the flows are divided into two streams of water. The first stream is diverted from the SAR to Weir Ponds 1-4 (Desilting System). The second stream is the remaining flow, which is bypassed around the dam and placed back into the SAR channel. The maximum flow that can be diverted to the Desilting System is 5 cubic feet per second (cfs). Up to 5 cfs can also be bypassed around the dam. Flows that pass through the Desilting System are split at Weir Pond 4 with up to 4 cfs being conveyed to Foster-Huckleberry, Conrock, Warner, and Little Warner Basins (Warner System). At Little Warner Basin, water is conveyed via the 66-inch diameter Warner Transmission Pipeline to Anaheim Lake. Water reaching Anaheim Lake can also be conveyed via a pipeline around the north side of Anaheim Lake to downstream basins, including Mini-Anaheim Lake, Kraemer Basin, Miller Basin, La Jolla Basin, Placentia Basin, and Raymond Basin. Water conveyed from Weir 4 to the Off-River Channel flows downstream where some flows into Olive Basin. Left over water that does not percolate in the Off-River Channel then flows into Five Coves Basins via tubes under Carbon Canyon Diversion. Similar to the Imperial Highway Rubber Dam, water reaching Five Coves Rubber Dam is split into two streams, with one stream diverted to the Five Coves Basins and the other stream bypassed around the dam back into the SAR channel. The Five Coves Rubber Dam has a maximum diversion capacity of 5 cfs and a maximum bypass capacity of 25 cfs. Water bypassed around the dam to the SAR channel must be carefully monitored so water is not lost to the ocean. 17

25 Table 4-1 Area and Storage Capacity of Surface Water Recharge Facilities Facility Max. Wetted Area Facility Invert Elev. Max. Water Surface Elevation (1) Max. Storage Capacity (1) (acres) (ft msl) (ft msl) (af) Anaheim Lake ,26 Burris Basin ,67 Conrock Basin (Warner System) ,7 Five Coves Basin: Lower Five Coves Basin: Upper Foster-Huckleberry Basin (Warner System) Kraemer Basin ,17 La Jolla Basin Lincoln Basin Little Warner Basin (Warner System) Miller Basin (2) Mini-Anaheim Lake Off-River Channel N/A N/A Olive Basin Placentia Basin (2) Raymond Basin (2) River View Basin Santa Ana River: Imperial Hwy to Orangewood Ave N/A N/A Santiago Basins ,72 Santiago Creek: Santiago Basins - Hart Park (3) N/A N/A Warner Basin ,62 Weir Pond Weir Pond Weir Pond Weir Pond Totals 1,68 26,215 Notes: (1) Maximum water surface elevation is typically not achieved for most facilities due to need to reserve buffer space for system flow and level fluctuations. Elevations and storage volumes are not applicable (N/A) to stream/river channels. (2) Owned by Orange County Flood Control District (OCFCD). Max., storage capacity shown is max. flood control storage. (3) Various owners, including OCFCD, City of Orange, and MWD. 18

26 Water that enters Five Coves Basins passes to Lincoln Basin and then into Burris Basin. From Burris Basin, water is pumped to Santiago Basins via the Burris Basin Pump Station. The pump station has four incline-turbine pumps, which have a combined pumping capacity of 235 cfs or 15,5 gallons per minute. Pumped water is conveyed to the Santiago Basins via the Santiago Pipeline, which is approximately five miles long (see Figure 2-2). Water in the Santiago Pipeline also supplies River View Basin and Santiago Creek. A pump station in Santiago Basins allows the District to reverse the flow direction in the Santiago Pipeline and pump stored water from the basins to Santiago Creek, River View Basin, Burris Basin, and to the SAR channel. Pumping from the Santiago Basins is typically done during the fall months to maximize storage space for storm water capture. Due to suspended sediment in SAR water, all of the recharge facilities clog, resulting in reduced recharge rates over time. To mitigate clogging of the SAR channel, the District stirs up the top few inches of sediment using heavy equipment, which forces the accumulated fine-grained sediments to be re-suspended and flow downstream. In the other facilities, cleaning is accomplished by draining the water from the facilities, allowing the accumulated fine-grained sediments to dry, and then removing them from the bottom using heavy equipment. The basin sidewalls, which typically have 3:1 slopes, are disturbed using bulldozers. This action breaks up the clogging layer, but does little to remove it. Seven recharge basins have permanently installed dewatering pumps that allow the District to rapidly dewater the basins for cleanings. Other facilities are drained by gravity. Generally, the District will take a basin out of service for cleaning when the recharge rate declines by 65 to 75 percent of the starting, clean recharge rate. Terminal recharge basins, including Anaheim Lake, Kraemer Basin, Miller Basin, La Jolla Basin, and River View Basin, can easily be taken off-line and cleaned without affecting other facilities. However, flowthrough basins, such as Weir Ponds 1-4, Warner Basin, Five Coves Basins, Lincoln Basin, and Burris Basin, cannot be easily taken off-line without affecting downstream facilities. As a result, flow-through basins are not cleaned as often as the terminal basins. 19

27 4.2 Santa Ana River Channel Key Facts: Wetted Area: 291 acres Maximum Water Depth: N/A Maximum Storage Capacity: N/A Year Placed Into Service: 1936 Water Sources: SAR, Imported/Purchased Water The Santa Ana River channel is OCWD s single largest and oldest recharge facility. It is also one of the most effective recharge facilities due to the self-cleaning nature of the channel. The District owns six miles of the SAR channel extending from Imperial Highway (SR9) to Ball Road, as shown on Figure 2-2. The river channel is actively managed with heavy equipment to maximize the wetted surface area of the channel and to remove accumulated fine-grained sediments that coat and clog the channel bottom. Maximizing the wetted surface area is typically done by constructing sand levees in the channel to force the water to spread out. The sand levees wash out during storm events and thus do not hinder the storm flow conveyance capacity of the channel. Table 4-2 summarizes the monthly recharge provided by the Santa Ana River channel in Table 4-2 Monthly Recharge in Santa Ana River Channel, 29-1 Month Recharge (af) Notes July 29 4,6 August 29 4,693 September 29 4,791 October 29 5,373 November 29 5,16 December 29 5,633 January 21 6,112 February 21 5,589 March 21 5,79 April May 21 5,212 June 21 5,16 Total 63,399 5-Year Avg 62,56 Average for FY5-6 to FY9-1 2

28 4.3 Weir Ponds 1 4 (Desilting System) Key Facts: Wetted Area: 33 acres Maximum Water Depth: 12 feet Maximum Storage Capacity: 252 af Year Placed Into Service: 1973 Water Sources: SAR, Imported/Purchased Water Water diverted from the SAR Channel at Imperial Rubber Dam enters Weir Ponds 1 to 4, which collectively comprise the Desilting System. This system mainly provides sediment removal and little to no recharge. Aside from high solids loading that clogs the system; recharge is further inhibited by shallow groundwater conditions in the area. In 24, OCWD installed a fourth generation Basin Cleaning Vehicle (BCV-4) in Weir Pond 3, which is described further in previous annual reports. Due to below expected performance, the BCV in Weir Pond 3 was taken off-line and is no longer being operated. Weir Ponds 1 and 2 do not provide any meaningful recharge and thus are not included in the table below. Table 4-3 summarizes the monthly recharge provided by Weir Pond 3 in Table 4-3 Monthly Recharge in Weir Pond 3, 29-1 Month Recharge (af) Notes July Estimated August 29 8 Estimated September 29 4 Estimated October Estimated November 29 8 Estimated December 29 6 Estimated January 21 6 Estimated February 21 6 Estimated March 21 6 Estimated April 21 6 Estimated May 21 6 Estimated June 21 6 Estimated Total Year Avg 842 Average for FY5-6 to FY9-1 21

29 4.4 Warner Basin System Key Facts: Wetted Area: 127 acres Maximum Water Depth: 52 feet Maximum Storage Capacity: 4,545 af Year Placed Into Service: 1974 Water Sources: SAR, Imported/Purchased Water Warner Basin, named after long-time Orange County Supervisor and OCWD Board member, Willis H. Warner, is a large, deep recharge basin that was put into service in The Warner Basin System is comprised of Foster-Huckleberry, Conrock, Warner, and Little Warner Basins. Foster-Huckleberry and Conrock Basins are not cleaned or maintained and therefore serve more as desilting basins than as recharge basins. Warner Basin was last cleaned in summer 26. Consequently, the annual recharge for 29-1 is below average. It is difficult to clean Warner Basin due to the large volume of water that must be evacuated and the length of time it takes to dry and clean the basin. Table 4-4 summarizes the monthly recharge provided by the Warner Basin System in Table 4-4 Monthly Recharge in Warner Basin System, 29-1 Month Recharge (af) Notes July August 29 7 September October November December January February March April 21 1,26 May June Total 8,679 5-Year Avg 14,46 Average for FY5-6 to FY9-1 22

30 4.5 Anaheim Lake Key Facts: Wetted Area: 72 acres Maximum Water Depth: 49 feet Maximum Storage Capacity: 2,26 af Year Placed Into Service: 1961 Water Sources: SAR, Imported/Purchased Water Anaheim Lake is the District s oldest deep recharge basin, having been put into service in From 1961 to 1975, only imported water from MWD was recharged in the basin. Since the completion of the Warner Transmission Pipeline connecting Warner Basin with Anaheim Lake in 1975, both SAR water and MWD water have been recharged in Anaheim Lake. Anaheim Lake was drained and cleaned in September 29. Large amounts of imported water from MWD were recharged in the basin in July-August 29 and May-June 21. Table 4-5 summarizes the monthly recharge provided by Anaheim Lake in Table 4-5 Monthly Recharge in Anaheim Lake, 29-1 Month Recharge (af) Notes July 29 2,112 OC-28 and SAR inflow August 29 3,943 OC-28 and SAR inflow September SAR inflow, begin cleaning October 29 Out of service for cleaning, maintenance November Basin cleaned, SAR inflow December 29 3,385 SAR inflow January 21 2,615 SAR inflow February 21 3,547 SAR inflow March 21 3,354 SAR inflow April 21 2,43 SAR inflow May 21 2,756 OC-28 and SAR inflow June 21 1,52 OC-28 and SAR inflow Total 26,766 5-Year Avg 27,944 Average for FY5-6 to FY9-1 23

31 4.6 Mini-Anaheim Lake Key Facts: Wetted Area: 5 acres Maximum Water Depth: 4 feet Maximum Storage Capacity: 13 af Year Placed Into Service: 1995 Water Sources: SAR, Imported/Purchased Water Mini-Anaheim Lake is a small, shallow basin that was constructed on land just east of Anaheim Lake. The basin can receive SAR water, purchased water, and imported water from the adjacent OC- 28/28A connection. Table 4-6 summarizes the monthly recharge provided by Mini-Anaheim Lake in Table 4-6 Monthly Recharge in Mini-Anaheim Lake, 29-1 Month Recharge (af) Notes July OC-28 inflow August OC-28 inflow September 29 Not used October 29 Not used November Used 3 days December SAR and pumped from Anaheim Lake January SAR and pumped from Anaheim Lake February SAR and pumped from Anaheim Lake March SAR and OC-28 inflow April SAR and OC-28 inflow May SAR and OC-28 inflow June SAR and OC-28 inflow Total 3,84 5-Year Avg 3,756 Average for FY5-6 to FY9-1 24

32 4.7 Kraemer Basin Key Facts: Wetted Area: 31 acres Maximum Water Depth: 56 feet Maximum Storage Capacity: 1,17 af Year Placed Into Service: 1988 Water Sources: SAR, Imported/Purchased, Recycled Water Kraemer Basin is a 31 acre deep basin that was put into service in Due to the coarse sands and gravels that underlie the basin and high depth to groundwater (>1 feet), Kraemer Basin is one of the most efficient recharge basins on a per-acre basis operated by OCWD. Kraemer Basin was taken out of service in September-November 29 for installation of refurbished dewatering pumps and new power cables. The basin was also cleaned in May 21. Table 4-7 summarizes the monthly recharge provided by Kraemer Basin in Table 4-7 Monthly Recharge in Kraemer Basin, 29-1 Month Recharge (af) Notes July 29 1,626 GWRS and OC-28 inflow August OC-28 inflow September Basin drained for maintenance October 29 Basin drained for maintenance November Basin placed back on-line December 29 2,71 Pumped water from Ana. Lake January 21 1,224 GWRS inflow and pumped from Ana. Lake February 21 4,85 GWRS inflow and pumped from Ana. Lake March 21 4,55 SAR and OC-28 inflow April 21 3,273 SAR and OC-28 inflow May Dewatered for cleaning June 21 1,776 Placed back on-line Total 19,661 5-Year Avg 2,776 Average for FY5-6 to FY9-1 25

33 4.8 Miller Basin Key Facts: Wetted Area: 25 acres Maximum Water Depth: 24 feet Maximum Storage Capacity: 3 af Year Placed Into Service: 1963 Water Sources: SAR, Imported/Purchased, Recycled Water Miller Basin is a flood retarding basin owned by the OCFCD that was constructed in The OCFCD allows OCWD to use the basin for recharge as long as water levels are kept within certain limits (OCWD, 21; OCWD, 23c). In 24, OCWD installed a fourth generation Basin Cleaning Vehicle (BCV-4) in Miller Basin, which is described further in previous annual reports. Because of the high recharge rates seen with GWR System water, the BCV was not operated for much of Miller Basin was dedicated to the recharge of GWR System water for most of A flood event in January 21 caused water from the adjacent Carbon Canyon Diversion channel to spill into the basin, which clogged the basin. GWRS water was recharged in Kraemer Basin while Miller Basin was being cleaned. The continued dedication of GWR System water recharge in Miller Basin resulted in above-average recharge in Table 4-8 summarizes the monthly recharge provided by Miller Basin in Table 4-8 Monthly Recharge in Miller Basin, 29-1 Month Recharge (af) Notes July 29 1,798 GWRS inflow August 29 2,827 GWRS inflow September 29 2,495 GWRS inflow October 29 2,477 GWRS inflow November 29 2,23 GWRS inflow December 29 2,754 GWRS inflow January 21 1,647 GWRS and overflow from Carbon Div. February Basin cleaned, GWRS inflow March 21 2,88 GWRS inflow April 21 2,89 OC-28 and GWRS inflow May 21 2,86 OC-28, GWRS and SAR inflow June 21 2,3 OC-28, GWRS and SAR inflow Total 27,345 5-Year Avg 16,617 Average for FY5-6 to FY9-1 26

34 4.9 La Jolla Basin Key Facts: Wetted Area: 6.5 acres Maximum Water Depth: 5 feet Maximum Storage Capacity: 26 af Year Placed Into Service: 27 Water Sources: Carbon Creek, SAR, Imported/Purchased Water La Jolla Basin is the District s newest recharge basin and was put into service in December 27. Water is diverted to the basin via a small rubber dam in Carbon Creek. Water in Carbon Creek is typically SAR or imported water discharged to the creek near Miller Basin. Due to the highly permeable sediments underlying the basin, recharge rates on a per- acre-basis, are the highest of any facility operated by OCWD. Table 4-9 summarizes the monthly recharge provided by La Jolla Basin in Table 4-9 Monthly Recharge in La Jolla Basin, 29-1 Month Recharge (af) Notes July 29 Not in use August 29 Not in use September 29 Not in use October 29 Not in use November SAR inflow December Pumped water from Anaheim Lake January Pumped water from Anaheim Lake February Pumped water from Anaheim Lake March SAR and OC-28 inflow April SAR and OC-28 inflow May SAR and OC-28 inflow June SAR and OC-28 inflow Total 4,43 5-Year Avg N/A Placed in service December 27 27

35 4.1 Placentia Basin Key Facts: Wetted Area: 9 acres Maximum Water Depth: 4 feet Maximum Storage Capacity: 35 af Year Placed Into Service: 1962 Water Sources: Carbon Creek, SAR, Imported/Purchased Water Placentia Basin is a flood retarding basin owned by the OCFCD that was constructed in The basin is designed to retard flood flows in Carbon Creek; however, the OCFCD allows OCWD to use 2 acre-feet of basin storage for water conservation (OCFCD, 1975). Even though OCWD can use the basin year-round, historically, OCWD has only used the basin during OCFCD s non-storm season (April 15- October 15). In 29-1, Placentia Basin was not actively used for recharge by OCWD. Approximately two to four acre-feet per day of treated groundwater is discharged to the basin from a treatment system located on the eastern edge of the basin. Rather than pump this water from the basin in order to clean it, OCWD bypassed this basin to use downstream Raymond Basin. Table 4-1 summarizes the monthly recharge provided by Placentia Basin in Table 4-1 Monthly Recharge in Placentia Basin, 29-1 Month Recharge (af) Notes July 29 Not used August 29 Not used September 29 Not used October 29 Not used November 29 Not used December 29 Not used January 21 Not used February 21 Not used March 21 Not used April 21 Not used May 21 Not used June 21 Not used Total 5-Year Avg 1,149 Average for FY5-6 to FY9-1 28

36 4.11 Raymond Basin Key Facts: Wetted Area: 19 acres Maximum Water Depth: 25 feet Maximum Storage Capacity: 37 af Year Placed Into Service: 1962 Water Sources: Carbon Creek, SAR, Imported/Purchased Water Raymond Basin is a flood retarding basin owned by the OCFCD that was constructed in The basin is designed to retard flood flows in Carbon Creek; however, the OCFCD allows OCWD to recharge water provided that the inflow matches the percolation rate (i.e., no stored water) (OCFCD, 1975). Even though OCWD can use the basin year-round, historically, OCWD has only used the basin during OCFCD s non-storm season (April 15- October 15). In 29-1, Raymond Basin was used for 3 months, resulting in below-average recharge for the year. Table 4-1 summarizes the monthly recharge provided by Raymond Basin in Table 4-11 Monthly Recharge in Raymond Basin, 29-1 Month Recharge (af) Notes July 29 4 No inflow, recharge of stored water. August 29 Not used September 29 Not used October 29 Not used November 29 Not used December 29 Not used January 21 Not used February 21 Not used March 21 Not used. April OC-28 and SAR inflow May OC-28 and SAR inflow June OC-28 and SAR inflow Total 1,178 5-Year Avg 1,847 Average for FY5-6 to FY9-1 29

37 4.12 Off-River Channel Key Facts: Wetted Area: 89 acres Maximum Water Depth: N/A Maximum Storage Capacity: N/A Year Placed Into Service: 1936 Water Sources: SAR, Imported/Purchased Water The Off-River Channel was part of the main SAR channel prior to completion of the Santa Ana River Water Conservation and Flood Control Project in December This project included installation of the center levee which created the main SAR channel for flood control and a parallel off-river channel for water conservation. When high flows are conveyed though the Off-River Channel, the excess water that does not percolate in the channel enters the Five Coves Basins. Periodic stream flow measurements are made in the Off-River Channel prior to entry into the Five Coves Basins to estimate recharge in the Off-River Channel. Table 4-11 summarizes the monthly recharge provided by the Off-River Channel in Table 4-12 Monthly Recharge in Off-River Channel, 29-1 Month Recharge (af) Notes July Estimated August Estimated September October November December Estimated January Estimated February Estimated March Estimated April Estimated May Used for 13 days, estimated 5 cfs/day June Used only 2 days Total 3,88 5-Year Avg 4,38 Average for FY5-6 to FY9-1 3

38 4.13 Olive Basin Key Facts: Wetted Area: 5.8 acres Maximum Water Depth: 41 feet Maximum Storage Capacity: 122 af Year Placed Into Service: 1973 Water Sources: SAR, Imported/Purchased Water Olive Basin is a former sand and gravel borrow pit that was purchased by the District in 1972 from the State of California, Division of Highways. Significant improvements were made to Olive Basin in In fall 29, weir plates were installed to allow for accurate inflow measurements. Transducer data allowing for the calculation of inflow and basin levels were connected to the District s SCADA system. In summer 21 a permanent dewatering pump was installed to allow for rapid draining and basin cleaning. Table 4-13 Monthly Recharge in Olive Basin, 29-1 Month Recharge (af) Notes July Estimated August 29 8 Dewatered for cleaning September 29 October November December January February March April Being drained May 21 Dewatered for construction project June 21 Dewatered for construction project Total 2,162 5-Year Avg N/A Returned to service in January 28 31

39 4.14 Five Coves Basins Key Facts: Wetted Area: 31 acres Maximum Water Depth: 18 feet Maximum Storage Capacity: 346 af Year Placed Into Service: 1975 Water Sources: SAR, Imported/Purchased Water In 24, OCWD installed fourth generation Basin Cleaning Vehicles (BCV-4) in Upper and Lower Five Coves Basins, which is described further in previous annual reports. Due to the heavy sediment load to Upper Five Coves Basins and lower than expected performance, operation of the BCV in Upper Five Coves basin ceased in April 26. Operation of the BCV in Lower Five Coves basin continues sporadically to continue testing the concept. Due to previous poor performance and inability to measure small changes in percolation rates in these basins, it is assumed that the BCV in Lower Five Coves did not result in any additional recharge in The Five Coves Basins were off-line in July-October 29 and starting in June 21 to allow for construction in Lincoln and Burris Basins. Table 4-14 summarizes the monthly recharge provided by Five Coves Basins in Table 4-14 Monthly Recharge in Five Coves Basins, 29-1 Month Recharge (af) Notes July 29 Off-line August 29 Off-line September 29 Off-line October 29 Off-line November Placed into service December 29 1,62 Estimated January Estimated February Estimated March Estimated April Estimated May Used for 13 days June 21 Off-line Total 5,316 5-Year Avg 3,157 Average for FY5-6 to FY9-1 32

40 4.15 Lincoln Basin Key Facts: Wetted Area: 1 acres Maximum Water Depth: 7 feet Maximum Storage Capacity: 6 af Year Placed Into Service: 1976 Water Sources: SAR, Imported/Purchased Water Lincoln Basin is a small basin that primarily serves to convey water from Five Coves Basins to Burris Basin. The District undertook a project to remove the fine-grained sedimentary layers underlie the basin in an effort to increase the recharge capacity of the basin. This project started in the summer of 29 and was completed in the fall of 29. Short-term percolation tests conducted after the project was completed indicated that recharge rates were lower than expected. Staff is continuing to investigate the potential reasons for this, including overcompaction of the fill material. 33

41 4.16 Burris Basin Key Facts: Wetted Area: 12 acres Maximum Water Depth: 62 feet Maximum Storage Capacity: 2,67 af Year Placed Into Service: 1977 Water Sources: SAR, Imported/Purchased, Santiago Basin Burris Basin is a large basin that includes a shallow eastern side that is a remnant of the SAR channel and a deeper western side that was a former sand and gravel mine. Recharge rates for Burris Basin are relatively low given the size of the basin. Reasons for the low recharge rates include large areas in the former gravel mine section of the basin that are covered with low permeability materials, low permeability materials that were used to shore up the basin sidewalls, and the fact that this basin is rarely drained and cleaned. The District started a project to remove the fine-grained layers in the northern part of the basin to increase the recharge capacity of the basin. This project is expected to be completed in the fall of 21. With the basin being empty for nearly half of the year, total basin recharge for 29-1 is below average. Table 4-15 summarizes the monthly recharge provided by Burris Basin in Table 4-15 Monthly Recharge in Burris Basin, 29-1 Month Recharge (af) Notes July No inflow, under construction August No inflow, under construction September 29 6 No inflow, under construction October 29 6 No inflow, under construction November 29 6 Inflow from Santiago Basins December 29 1,696 Inflow from SAR and Santiago Basins January 21 1,915 Inflow from SAR and Santiago Basins February 21 1,375 Inflow from SAR and Santiago Basins March 21 1,351 Inflow from SAR April 21 1,131 Inflow from SAR May Inflow from SAR June 21 6 Inflow from SAR Total 8,51 5-Year Avg 9,3 Average for FY5-6 to FY9-1 34

42 4.17 River View Basin Key Facts: Wetted Area: 3.6 acres Maximum Water Depth: 4 feet Maximum Storage Capacity: 11 af Year Placed Into Service: 23 Water Sources: SAR, Imported/Purchased, Santiago Basin River View Basin is located on the eastern side of the SAR channel across from Burris Basin. Water is provided to the basin via the Santiago Basin Pipeline. Typically during the winter months, pumped SAR water from the Burris Basin Pump station is supplied to the basin. In the summer months, pumped water from the Santiago Basins is supplied to the basin. Table 4-16 summarizes the monthly recharge provided by River View Basin in Table 4-16 Monthly Recharge in River View Basin, 29-1 Month Recharge (af) Notes July 29 Not used August 29 Not used September 29 Not used October 29 Not used November Inflow from Santiago Basins December Inflow from Burris and Santiago Basins January Inflow from Burris and Santiago Basins February Inflow from Burris and Santiago Basins March Inflow from Burris Basin April Inflow from Burris Basin May 21 1 Inflow from Burris Basin, Cleaned June Inflow from Burris Basin Total 1,154 5-Year Avg 1,474 Average for FY5-6 to FY9-1 35

43 4.18 Santiago Basins Key Facts: Wetted Area: 187 acres Maximum Water Depth: 136 feet Maximum Storage Capacity: 13,72 af Year Placed Into Service: 199 Water Sources: SAR, Imported/Purchased, Santiago Creek Santiago Basins are three former gravel and sand mines called Smith Pit, Blue Diamond Pit and Bond Pit (see Figure 2-2) that were purchased by OCWD in The combined storage capacity of the basins is over 13, acre-feet, which is over half of the total storage capacity of OCWD s entire surface water recharge system. Water supplied to the basin includes local runoff from Santiago Creek and pumped water from the Burris Basin Pump Station. In the summer months, water is typically pumped from the basins to downstream recharge facilities to create storage space for storm water capture. In February 21, 38 acre-feet of storm water from Villa Park Dam was released to Santiago Basins. Table 4-17 summarizes the monthly recharge provided by the Santiago Basins in Table 4-17 Monthly Recharge in Santiago Basins, 29-1 Month Recharge (af) Notes July 29 1,335 No inflow, recharge of stored water August No inflow, recharge of stored water September No inflow, recharge of stored water October No inflow, recharge of stored water November No inflow, recharge of stored water December Inflow from Burris Basin and Santiago Ck January 21 2,163 Inflow from Burris Basin and Santiago Ck February 21 5,678 Inflow from Burris Basin and Santiago Ck March 21 6,187 Inflow from Burris Basin and Santiago Ck April 21 5,628 Inflow from Burris Basin and Santiago Ck May 21 5,84 Inflow from Burris Basin and Santiago Ck June 21 2,595 Inflow from Burris Basin and Santiago Ck Total 31,96 5-Year Avg 38,711 Average for FY5-6 to FY9-1 36

44 4.19 Santiago Creek Channel Key Facts: Wetted Area: 2.6 acres Maximum Water Depth: N/A Maximum Storage Capacity: N/A Year Placed Into Service: 2 Water Sources: SAR, Imported/Purchased, Santiago Creek The upstream portion of Santiago Creek below Villa Park Dam drains into the Santiago Basins. So unless Santiago Basins are spilling, which can occur during wet years, upstream discharges of local runoff to the creek are captured and recharged in Santiago Basins. The downstream portion of Santiago Creek is generally fed by water pumped to the creek by OCWD. Typically water discharged to the creek in the winter months is pumped SAR water from the Burris Basin Pump Station. When there is sufficient local rainfall, discharge to the creek is curtailed or stopped to allow for the recharge of local runoff and minimize discharges through Hart Park. During the summer months, water supplied to the creek is pumped water from Santiago Basins. Table 4-18 summarizes the monthly recharge provided by Santiago Creek in Table 4-18 Monthly Recharge in Santiago Creek Channel, 29-1 Month Recharge (af) Notes July 29 Not used August 29 Not used September Inflow from Santiago Basins October Inflow from Santiago Basins November Inflow from Santiago Basins December Inflow from Burris and Santiago Basin January Inflow from Burris and Santiago Basin February Inflow from Burris and Santiago Basin March Inflow from Burris Basin April Inflow from Burris Basin May Inflow from Burris Basin June Inflow from Burris Basin Total 3,553 5-Year Avg 3,15 Average for FY5-6 to FY9-1 37

45 Section 5 Seawater Barrier Recharge This section summarizes the operation of the seawater barrier facilities in Talbert Gap Seawater Barrier To hold back seawater intrusion in the Talbert Gap, the District constructed the Talbert Gap Seawater Barrier (Talbert Barrier) in the mid-197s in the city of Fountain Valley (Figure 5-1). The Talbert Barrier currently has 36 injection sites with 18 injection well casings. Some of the older injection well sites have a large borehole with multiple injection well casings completed at different depths. New injection wells are periodically added if there is evidence of additional seawater intrusion. Historically, a mixture of recycled water, potable imported water, and groundwater has been used to supply the Talbert Barrier. From 1976 to June 24, recycled water was produced by Water Factory 21 (WF21). Starting in January 28, recycled water was supplied to the barrier by the newly completed Groundwater Replenishment System (GWR System). Total injection at the Talbert Barrier in 29-1 was a record 36,51 acre-feet, which is more than double the 1-year average of 16,884 acre-feet per year (see Table B-1 in Appendix B). Almost all of the water injected in 29-1 was recycled water. The record 38

46 setting injection in 29-1 was due to an aggressive injection well redevelopment program and the lack of clogging caused by the GWRS water compared to sources used previously. Figure 5-2 shows annual injection at the Talbert Barrier over the last 1 years. Table B-11 in Appendix B presents the data used to prepare this graph. Annual Recharge (af) 4, 35, 3, 25, 2, 15, 1, Groundwater Recycled Water Imported Water Avg. 16,884 afy 5, Year 5.2 Alamitos Gap Seawater Barrier Figure 5-2 Annual Injection at the Talbert Barrier, 2-1 The first segment of the Alamitos Barrier was designed and constructed in 1965 to create a freshwater pressure ridge intended to protect the groundwater supplies of both the Orange Country groundwater basin and Central Basin in Los Angeles County from seawater intrusion. As shown in Figure 5-3, the barrier straddles the Orange-Los Angeles County line and spans the approximately 1.8-mile wide Alamitos Gap between Bixby Ranch Hill and Landing Hill. The barrier is comprised of 43 injection wells and more wells are added as needed to minimize further seawater intrusion. Since the barrier straddles the LA-OC county line, only a third of total injection recharges the Orange County groundwater basin. 39

47 Total injection at the Alamitos Barrier in 29-1 was 5,631 acre-feet, which is approximately nine percent greater than the recent 1-year average of 5,168 acre-feet per year (see Table B-12 in Appendix B). Of the 5,631 acre-feet injected, 1,322 acre-feet was injected on the Orange County side of the barrier. This is approximately 15 percent less than the recent 1-year average of 1,553 acre-feet per year recharged into the Orange County side of the barrier. Figure 5-4 shows annual injection to the Orange County groundwater basin from the Alamitos Barrier from 2 to 21. Table B-13 in Appendix B presents the data used to prepare this graph. 4

48 2,5 2, Imported Water Recycled Water Note: Only recharge to OC groundwater basin is shown. Annual Recharge (af) 1,5 1, Avg. 1,553 afy Year Figure 5-4 Annual Injection at the Alamitos Barrier,

49 Section 6 In-Lieu Recharge Since the in-lieu program was put into place by MWD in 1977, the District has recharged over 91, acre-feet of imported water as shown on Figure 6-1. The program is administered by the Municipal Water District of Orange County (MWDOC) and is the most successful in-lieu program in MWD s service territory. When surplus water is available from MWD, OCWD initiates the program and asks groundwater pumpers to turn off their wells and take treated, imported water in-lieu of groundwater. Pumpers that participate in the program are paid by OCWD to make the water cost equivalent to the cost of pumping groundwater. In 29-1, no water was available from MWD for the in-lieu program. Table B-14 in Appendix B presents the data used to prepare Figure , 9, 8, Annual Recharge (af) 7, 6, 5, 4, 3, 2, 1, * 1992* 1993* 1994* 1995* 1996* 1997* 1998* 1999* 2* 21* 22* 23* 24* 25* 26* 27* 28* 29* 21* * , July 1-June 3, Other years Oct. 1 - Sept. Year Figure 6-1 Annual In-Lieu Recharge,

50 Section 7 Recharge Summary This section summarizes the sources of recharge used to recharge the basin and the facilities used to recharge these sources in Recharge Sources A total of inches of rain was received at the District s Anaheim Field Headquarters which is approximately 2 percent above the historical average of 14.4 inches and broke a string of four consecutive years of below average rainfall. The above-average rainfall also resulted in above average storm flow and incidental recharge. Since 24-5, Santa Ana River base flows have declined over 33 percent; however, flows appear to have leveled off with the 29-1 flow of 12,599 acre-feet only 3, acre-feet less than the 28-9 flow (15,49 acre-feet). Compared to the last 1 years, Santa Ana River base flow recharge in 29-1 is 24 percent below average. The decline is attributed to increased conservation by upstream agencies, increased recycling, and reduced economic activity in upper watershed. Imported water recharge was 69 percent below the 1-year average due to restrictions on the amount of imported water available to OCWD. Recycled water recharge was a historic high of 66,56 acre-feet. This source of recharge largely offset the reduced recharge from imported water and reduced SAR base flow. Figure 7-1 shows the monthly contribution of recharge sources in This figure shows that storm flow recharge dominates during the winter months (December-March). Recycled water from the GWR System provided a steady and significant recharge source throughout the year. Table B-17 in Appendix B presents the data used to prepare Figure

51 45, Monthly Recharge (af) 4, 35, 3, 25, 2, 15, Incidental Recharge Recycled Water Imported/Purchased Water Storm Flow/Local Water SAR Base Flow 1, 5, Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Month Figure 7-1 Total Monthly Recharge by Source, 29-1 In 29-1, SAR base flow provided 31 percent of total recharge, with SAR storm flow and local inflow providing 18 percent. Taken together, SAR and local flows provided 49 percent of total recharge to the basin. Imported and purchased water provided 6 percent of total recharge while recycled water provided an all time high of 2 percent. Figure 7-2 shows the relative contribution of each recharge source in

52 83,239 af 25% SAR Base Flow Storm Flow/Local Water Imported/Purchased Water Recycled Water Incidental Recharge Volumes are in acre-feet 12,599 af 31% 66,56 af 2% 21,586 af 6% 61,35 af 18% Figure 7-2 Recharge Sources, 29-1 Total recharge to the basin in 29-1 was 334,965 acre-feet, which is inline with the recent 1-year average of 338,995 acre-feet per year. Table 7-1 summarizes the recharge sources to the basin in 29-1 and how they compare to the recent 1-year average. Figure 7-3 shows how total recharge in 29-1 compared to the last 1 years. Tables B- 17 and B-18 in Appendix B present the data used to prepare Table 7-1, Figure 7-1 and Figure

53 Source Table 7-1 Recharge Source Summary FY9-1 (af) 1-Year Avg (af) Increase/ (Decrease) (af) % Increase/ (Decrease) SAR Base Flow (1) 12, ,699 (33,1) (24) Storm Flow/Local Water (2) 61,35 52,339 8, Imported/Purchased Water 21,586 7,498 (48,912) (69) Groundwater (3) 2,968 (2,968) (1) Recycled Water 66,56 15,961 5, Total OCWD Recharge (4) 251, ,465 (25,739) (9) Incidental Recharge 83,239 61,53 21,79 35 Grand Total 334, ,995 (4,3) (1) (1) SAR Base Flow based on OCWD data, which may differ slightly from the SAR Watermaster (see Section 3.2). (2) Storm flow includes local inflow to the recharge system below Prado Dam. (3) Groundwater was used to augment injection supplies at the Talbert Barrier until July 26. (4) Recharge at all OCWD facilities. Annual Recharge (af) 6, 5, 4, 3, 2, Incidental Recharge Groundwater Recycled Water Imported/Purchased Water Storm Flow/Local Water SAR Base Flow Avg. 339, afy 1, Fiscal Year Figure 7-3 Total Annual Recharge by Source,

54 7.2 Recharge Facilities The recharge of SAR and local water in the surface water recharge system was 13 percent below the recent 1-year average in 29-1 due to reduced SAR base flows. Recharge of imported water in the surface water system was also below average due to lack of imported supplies. Recharge of recycled water in the surface water recharge system was an all time high of 29,617 acre-feet. An aggressive well redevelopment program and continued sustained high injection rates achieved with the ultra-pure GWR System water resulted in a doubling of the average recharge rate at the Talbert seawater barrier. Table 7-2 summarizes the contribution of the different recharge facilities to basin recharge in 29-1 and how they compare to the recent 1-year average. In 29-1, the surface water recharge system provided 85 percent of total recharge in with the seawater barriers providing the remaining 15 percent, as shown in Figure 7-4. Because of the lack of imported water, the in-lieu recharge system was not used in Surface Water System: SAR/Local Water Surface Water System: Imported/Purchased Water Surface Water System: Recycled Water In-Lieu System Seawater Barrier System 37,832 af 15% Volumes are in acre-feet -, % 29,617 af 12% 2,642 af 8% 163,634 af 65% Figure 7-4 Recharge by Facility,

55 Facility Table 7-2 Recharge Facility Summary FY9-1 (af) 1-Year Avg (af) Increase/ (Decrease) (af) % Increase/ (Decrease) Surface Water System: SAR/Local Water 163, ,38 (24,44) (13) Surface Water System: Imported/Purchased Water 2,642 28,598 (7,956) (28) Surface Water System: Recycled Water (1) 29,617 6,259 23, In-Lieu System 36,132 (36,132) (1) Seawater Barrier System 37,832 18,438 19, Total OCWD Recharge 251, ,465 (25,74) (9) (1) Recharge of recycled water from GWR System in surface water system started in January 28. Figure 7-5 shows how recharge at each of the facilities has varied over the past 1 years. Table B-18 in Appendix B presents the data used to prepare Figures 7-4 and 7-5 and Table 7-2. Annual Recharge (af) 45, 4, 35, 3, 25, 2, 15, Seawater Barrier System In-Lieu System Surface Water System: Recycled Water Surface Water System: Imported/Purchased Water Surface Water System:SAR/Local Water Avg. 277,47 af 1, 5, Fiscal Year Figure 7-5 Total Annual Recharge by Facility,

56 Section 8 References California Department of Water Resources (DWR), Progress Report on the Groundwater Geology of the Coastal Plain of Orange County. Los Angles County Department of Public Works (LACDPW), 27. Alamitos Barrier Project, Annual Report on the Control of Seawater Intrusion, Prepared by Matt Frary and George Win. Orange County Flood Control District (OCFCD), 1975*. Carbon Creek System Manual. *Publication date estimated. Orange County Water District (OCWD), Orange County Water District 1975 Annual Report. April Orange County Water District (OCWD), Orange County Water District 1982 Annual Report. April Orange County Water District (OCWD), 21. Approve and authorize agreement D for GWR system pipeline construction with OCFCD for use of the OCFCD Santa Ana River right-of-way for construction of the GWR system pipeline. OCWD Board Resolution R , August 15, 21. Agreement No. D was approved by OCFCD on Oct. 23, 21. In addition to other things, this agreement formalized the use of Miller Basin by OCWD and requires preparation of a Water Conservation Plan. Orange County Water District (OCWD), 22. Engineer s Report: Basin Cleaning Vehicle No. 4 for Lower Five Coves Basin. Prepared by Max Rasouli, P.E. November 22. Orange County Water District (OCWD), 23a. A History of Orange County Water District. Published by OCWD. Orange County Water District (OCWD), 23b. Orange County Water District Recharge Study. December 23. Orange County Water District (OCWD), 23c. Miller Retarding Basin (facility E2B1) Water Conservation Plan. OCFCD and OCWD, September 23. Approved by OCWD Board in October 23 (R ). Orange County Water District (OCWD), 23d. Engineer s Report for La Jolla Recharge Basin. Prepared by Steve Conklin, P.E., Director of Engineering June 23. Orange County Water District (OCWD), 24. Groundwater Management Plan. March 24. Orange County Water District (OCWD), 27. Report on Evaluation of Orange County Groundwater Basin Storage and Operational Strategy. Prepared by Tim Sovich, P.E., and Roy Herndon, P.G., February

57 Santa Ana River (SAR) Watermaster, 21. Thirty-Ninth Annual Report of the Santa Ana River Watermaster for Water Year Oct. 1, 28 to Sept. 3, 29. April 3,21. Santa Ana River Watermaster for Orange County Water District vs. City of Chino et al., Case No County of Orange. Santa Ana River (SAR) Watermaster, 211. Fortieth-Seventh Annual Report of the Santa Ana River Watermaster for Water Year Oct. 1, 29 to Sept. 3, 21. April 3,211. Santa Ana River Watermaster for Orange County Water District vs. City of Chino et al., Case No County of Orange. Toups, Proposed Design of Water Conservation Facilities Along Santa Ana River Between Imperial Highway and Lakeview Avenue. Prepared for OCWD by Toups Engineers, Inc. August US Army Corps of Engineers (USACOE), Water Control Manual. Prado Dam & Reservoir, Santa Ana River, California. Prepared by USACOE, Los Angeles District, Reservoir Regulation Section (CESPL-ED-HR). September US Army Corps of Engineers (USACOE), 22. Interim Water Control Plan (During Construction). Prado Dam & Reservoir, Santa Ana River, Orange County, California. Prepared by USACOE, Los Angeles District, Reservoir Regulation Section (CESPL-ED- HR). November 22. US Fish and Wildlife Service (USFWS), 2. Letter to Colonel John P. Carroll, District Engineer, USACOE, Los Angeles District, Re: Formal Section 7 Consultation on the Prado Basin Water Conservation and Water Control Operations Project, Prado Basin, Riverside and San Bernardino Counties, California (Biological Opinion F-75). Prepared by Loren Hays and signed by Jim A. Bartel, Assistant Field Supervisor. February 1, 2. Warrick, Jonathan A., and David M. Rubin, 27. Suspended-sediment rating curve response to urbanization and wildfire, Santa Ana River, California. Journal of Geophysical Research, Vol. 112, F218. 5

58 Appendix A Acronyms/Definitions

59 af. Acre-foot. The amount of water needed to cover an acre of land with one foot of water (43,56 cubic feet, 325,9 gallons). afy. Acre-foot per year. Base flow. The portion of river surface flow which remains after deduction of storm flow and/or purchased imported water. BCV. Basin cleaning vehicle. cfs. Cubic-feet-per-second. Measure of water flow in a channel. Equivalent to 45 gallons per minute. In one 24-hour period, a flow of 1 cfs equals 1.98 acrefeet of water. Ft msl. Elevation in feet mean sea level. GWR System. Groundwater Replenishment System. LACDPW. Los Angeles County Department of Public Works. MWD. Metropolitan Water District of Southern California. MWDOC. Municipal Water District of Orange County. OCFCD. Orange County Flood Control District. OCWD. Orange County Water District. SAR. Santa Ana River. Storm flow. The portion of river surface flow that is attributed to rainfall. SWRCB. California State Water Resources Control Board. USACOE. United States Army Corps of Engineers. USGS. United States Geological Survey. WRD. Water Replenishment District of Southern California.

60 Appendix B Data Tables

61 The data presented in the tables within this appendix were derived from the following sources: Santa Ana River Watermaster Each year the SAR Watermaster prepares a report for the Superior Court of Orange County that presents the findings for the prior water year (WY, Oct. 1 to Sept. 3). The SAR Watermaster uses the final USGS record for the SAR below Prado Dam (Station No. 1174) to determine the daily volume of base flow and storm flow that arrived at Prado Dam. Orange County Water District As part of its aquifer recharge operations, OCWD collects a wide variety of data. Each of these data sources and their limitations are described in this section. Precipitation/Evaporation OCWD has been collecting precipitation data at its Anaheim Field Headquarters location since Formerly included in OCFCD s annual report, it was assigned Station no Prior to 27, precipitation was measured using a National Weather Service approved non-recording 8- inch rain gage. In 27, a tipping bucket rain gage was added to determine rainfall intensities and add accuracy. Evaporation data has been collected since 1988 using a National Weather Service approved 48- inch evaporation pan. Surface Water Flows A wide variety of methods are used to measure surface water flows in the recharge system, including flumes, weirs, ultrasonic flow meters, propeller meters, and magnetic flow meters. The data collection using these methods is done so according to standard hydrologic techniques. Every effort is made to ensure that the data collected are as accurate as possible. Where possible, flows from one area are cross-checked with flows measured at downstream facilities. Nevertheless, during the course of any year, there are periods when instrumentation problems and rapid changes in flow rates can make accurately identifying the recharge performance of individual facilities difficult, particularly over short time periods. Recharge Facility Water Levels Water levels in the recharge facilities are measured using several methods including pressure transducers, air pressure in orifice lines, and staff gages. At many sites, the water levels are collected on a continuous

62 basis and stored electronically. Water level data are used to operate the recharge system and to calculate storage changes. Storage changes, along with inflow and outflow rates, are used to calculate percolation rates. The water storage vs. water level elevation relationship for each facility is based on digitized topographic maps. Talbert Gap Seawater Barrier From 1976 to 26, water recharged in the Talbert Barrier was measured using a 3-inch differential pressure flow meter. Since 27, flows have been measured using a 54-inch ultrasonic flow meter. Incidental Recharge Incidental recharge is estimated by comparing changes in basin water levels from year to year. Recently, this method has been improved by calculating the change in storage from each of the basins three main aquifer systems. Imported Water Volumes of imported water purchased by OCWD for recharge are reported to OCWD by the selling agency, which could include the Municipal Water District of Orange County (MWDOC), Western Municipal Water District, San Bernardino Valley Municipal Water District, and Elsinore Valley Municipal Water District. Los Angeles County Department of Public Works The LACDPW provides OCWD with data on the water recharged at the Alamitos Seawater Barrier. Because the Alamitos Barrier straddles the Los Angeles and Orange County lines, the LACDPW presents the volume of water recharged on both sides of the county line in its annual report on the control of seawater intrusion at the Alamitos Gap (LACDPW, 27).

63 Table B-1 Monthly Rainfall at OCWD Field Headquarters, OCFCD* Station 172 Rainfall in inches per month YEAR JULY AUG SEPT OCT NOV DEC JAN FEB MAR APR MAY JUNE TOTAL AVG MAX Cum Avg *Orange County Flood Control District. Guage is maintained by OCWD staff and data reported to OCFCD.

64 Table B-2 Annual Incidental Recharge, 2-21 Fiscal Year (Jul-June) Net Incidental Recharge* (afy) 2-1 5, , , , , , , , , ,239 1-Yr Avg 61,53 *Losses to Los Angeles County are subtracted from total incidental recharge to yield net incidental recharge.

65 Table B-3 Monthly Local Inflow Summary, 29-1 Local Storm Flow to SAR Below Imperial Rubber Dam (1) Direct Rainfall to Recharge Basins (3) Local Storm Flow to Santiago Basins (2) Total Local Inflow (af/mo) (af/mo) (af/mo) (af/mo) Jul Aug Sep Oct Nov Dec Jan-1 1,2 1, ,897 Feb ,755 Mar Apr May Jun Total 2,6 3, ,594 (1) Includes estimated flow from Carbon Canyon Diversion. (2) Includes inflow from Santiago Creek and releases from Villa Park Dam (Table B-6). (3) Assumes direct rainfall to 5 acres of recharge basins.

66 Table B-4 Annual SAR Watermaster Base Flow and Storm Flow, (1) Oct-Sept Water Year SAR Base Flow SAR Storm Flow Total SAR Supply (afy) (afy) (afy) ,67 11,66 53, ,85 77,26 122, ,7 178,96 229, ,55 11,13 63, ,8 1,15 62, ,6 114,75 174, ,78 15,14 77, ,27 82,41 144, ,97 43,77 19, ,59 36,59 12, ,21 26,69 86, ,89 29,31 84, ,12 6,99 59, ,78 8,55 53, ,26 6,55 49, ,5 4,39 42, ,42 47,49 85, ,44 7,32 45, ,84 14,6 53, ,36 6,13 46, ,39 11,78 51, ,4 6,6 43, ,58 38,58 76, ,55 2,88 37, ,6 5,18 35, , , ,25 14,84 42, ,31 6,29 33, ,54 5,61 33, ,97 1,1 38, ,61 44,23 74, ,99 56,84 85, ,73 14,659 47, ,766 33, , ,856 11,625 5, ,42 13,462 51, ,416 11,327 51, ,999 28,485 77, ,16 19,45 62, ,176 11,679 61, ,627 13,582 59, ,387 14,566 62, ,51 194, , ,863 62, , ,59 445, , ,875 26,923 11, ,548 61, , ,692 36, , ,231 55, ,56 1 of 2

67 Table B-4 Annual SAR Watermaster Base Flow and Storm Flow, (1) Oct-Sept Water Year SAR Base Flow SAR Storm Flow Total SAR Supply (afy) (afy) (afy) ,23 37, , ,215 7, , ,848 23, , ,14 42, , ,572 33, , ,149 24, , ,151 75, , ,948 82, , ,68 438, , ,186 41, , , ,651 48, ,861 58,692 19, ,676 61, , ,711 3,64 456, ,637 23, , ,269 4, , ,915 54,621 28, ,891 1, , ,113 97,81 243, ,51 57,317 2, ,37 469, , ,736 85, , ,83 12,91 142, ,483 68, , ,711 53, , ,99 135, ,874 Maximum 158, , ,822 Minimum 26, ,95 Recent 1-yr Avg. 134,36 14, ,44 (1) Data from Santa Ana River Water Master Reports. 2 of 2

68 Table B-5 Monthly SAR Base and Storm Flow Recharged, 29-1 (1) Month SAR Base Flow SAR Storm Flow (2) Total SAR Water Recharged (af/mo) (af/mo) (af/mo) Jul-9 5,979-5,979 Aug-9 6,2-6,2 Sep-9 5,86-5,86 Oct-9 7, ,678 Nov-9 7, ,297 Dec-9 9,958 13,418 23,376 Jan-1 11,623 6,877 18,5 Feb-1 1,956 11,544 22,5 Mar-1 11,377 12,123 23,5 Apr-1 1,345 5,55 15,4 May-1 8,227 2,734 1,961 Jun-1 7,173 1,796 8,969 Totals 12,599 54, ,4 (1) OCWD data is used to determine SAR flows except during periods when the inflatable rubber dams are down. SAR base flow numbers shown in italics are based on SAR Watermaster data. (2) Total storm flow and local water captured and reported elsewhere in this report includes both the SAR component of storm flow and local runoff to the recharge system.

69 Table B-6 Monthly Santiago Creek Inflow, 29-1 Santiago Creek Inflow Water Released from Villa Park Dam Total Santiago Creek Inflow (af/mo) (af/mo) (af/mo) Jul Aug Sep Oct Nov Dec Jan-1 1,4 1,4 Feb Mar Apr May Jun Totals 2, ,27 Note: Santiago Creek inflow is categorized as storm flow, even though it may include nuisance flow during the summer months and releases from Villa Park Dam.

70 Table B-7 Monthly Recharge of Imported and Purchased Water, 29-1 Surface Water Recharge In-Lieu Recharge Seawater Barrier Recharge Totals Month OC-11 OC-28 OC-28A WMWD Arlington Desalter WMWD via Elsinore Valley MWD OCWD In-Lieu MWD In-Lieu (CUP*) Talbert Barrier Alamitos Barrier Total Imported Water Total Purchased Water Total Import/Purchased Water (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) Jul-9 1, , ,415 Aug-9 5, ,534 5,534 Sep Oct Nov Dec Jan Feb Mar-1 1, ,677 1,677 Apr-1 7, ,85 7,85 May-1 4, ,335 4,335 Jun Totals 2, , ,586 Notes: Imported water is purchased from MWD (from outside SAR watershed). Purchased water is from WMWD (from within SAR watershed) OC-11 and OC-28 provide only CRA water from Lake Matthews. OC-28A provides a mix of SWP and CRA water *MWD Conjunctive Use Program (CUP) In-lieu and seawater barrier purchase treated MWD water for recharge.

71 Table B-8 Monthly Recharge of Recycled Water, 29-1 Month Surface Water Recharge System Talbert Barrier Alamitos Barrier (1) Total Recycled Water (af/mo) (af/mo) (af/mo) (af/mo) Jul-9 2,494 3, ,66 Aug-9 2,89 3, ,4 Sep-9 2,484 3, ,832 Oct-9 2,55 3, ,871 Nov-9 2,32 1, ,31 Dec-9 2,732 2, ,389 Jan-1 2,687 3, ,29 Feb-1 2,16 2, ,679 Mar-1 2,83 3, ,972 Apr-1 2,415 3, ,728 May-1 2,214 3, ,796 Jun-1 2,39 3, ,515 Totals 29,617 36, ,56 Note: (1) Only that portion of Alamitos Gap Barrier recharge attributed to the Orange County groundwater basin is shown.

72 Table B-9 Monthly Losses to Ocean and Evaporation, 29-1 Losses to Ocean in SAR (1) Losses to Ocean in Santiago Creek Losses to Ocean in Carbon Creek Evaporation Losses (2) Total Losses (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) Jul Aug Sep Oct Nov Dec-9 1, 14 1,14 Jan-1 58, ,621 Feb-1 25, 12 25,12 Mar-1 3, 24 3,24 Apr May Jun Total 87,5 2,572 9,72 (1) As measured by OCWD at Ball Road guage. (2) Evaporation losses estimated to occur over 5 wetted acres. These losses are not accounted for in the overall total recharge calculations due to the small value and uncertainty related to the estimate.

73 Table B-1 Annual Injection for Talbert Barrier, Fiscal Year (Jul-Jun) Imported Water Recycled Water Groundwater Total (afy) (afy) (afy) (afy) ,557 7,876 14, ,829 8,193 15, ,161 6,695 14, ,42 3,937 8, ,738 2,614 5, ,68 2,33 5, ,814 1,272 3, ,153 1,76 3, ,489 2,543 6, ,773 4,837 1, ,63 8,242 1, ,656 4,143 7,186 13, ,49 3,867 5,78 11, ,72 1,784 4,94 1, ,821 4,155 2,92 17, ,56 4,86 1,169 11, , , ,581 1,72 14, ,14 28,952 33, ,333 36,51 Total 43,918 14,864 71, ,463 Annual Avg.* 4,392 7,43 3,584 12,823 1-Yr. Avg. 4,392 9,524 2,968 16,884 *Imported water average starts in 2.

74 Table B-11 Monthly Injection for Talbert Barrier, 29-1 Recycled Water Imported Water Total (af/mo) (af/mo) (af/mo) Jul-9 3, ,143 Aug-9 3,11 3,11 Sep-9 3, ,269 Oct-9 3, ,317 Nov-9 1, ,759 Dec-9 2,61 3 2,631 Jan-1 3,298 3,298 Feb-1 2, ,584 Mar-1 3, ,123 Apr-1 3, ,296 May-1 3,556 3,556 Jun-1 3, ,435 Total 36, ,51

75 Table B-12 Annual Injection for Alamitos Barrier, Fiscal Year (June-July) OC Total LAC (WRD) Total Grand Total OC Recycled* OC Imported LAC Recycled* LAC Imported Recycled Total Imported Total (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) 1,933 4,234 6,168 1,933 4,234 6,168 1,589 4,168 5,758 1,589 4,168 5,758 1,614 3,627 5,241 1,614 3,627 5,241 1,433 2,712 4,145 1,433 2,712 4, ,697 3, ,697 3,496 1,692 3,651 5,342 1,692 3,651 5,342 1,885 3,854 5,739 1,885 3,854 5,739 1,614 3,722 5,336 1,614 3,722 5,336 1,494 3,837 5,33 1,494 3,837 5,33 1,874 4,294 6,7 1,874 4,294 6,7 1,673 3,721 5,393 1,673 3,721 5,393 2,282 3,78 6,62 2,282 3,78 6,62 1,449 3,564 5,12 1,449 3,564 5,12 1,938 3,964 5,878 1,938 3,964 5,878 1,915 3,151 5,66 1,915 3,151 5, ,631 3, ,71 1,176 2, , ,54 4,467 5, , ,52 1,295 4, ,96 5,84 7, ,622 1,245 4,595 1,719 6, ,322 4,39 5, ,745 2,564 2,31 3,33 Total 31,454 72,971 14,33 1,782 29,672 5,14 67,957 6,797 97,56 Annual Avg. 1,582 3,665 5, , , ,917 1-Yr Avg. 1,553 3,618 5, , , ,488 Source: LACDPW *ABP did not use recycled water until October, 25. Annual averages for recycled water use starts in FY5-6. OC total LAC (WRD) Total

76 Table B-13 Monthly Injection for Alamitos Barrier*, 29-1 Recycled Water Imported Water Total (af/mo) (af/mo) (af/mo) Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Total ,322 *Only injection attributed to the OC groundwater basin is shown.

77 Table B-14 Annual In-Lieu Recharge of Imported Water, Year In-lieu Recharge of Imported Water (afy) , , , , , , , , , * 44, * 39, * 38, * 48, * 15, * 5, * 7, * 15, * 13, * 38,7 2-1* 18, * 19, * 61, * 52, * 69, * 89, * 5, * 28-9* 29-1* Totals 1-Yr. Avg. 36,134 From , Year ending Sept. 3. * Year Ending June 3 From Column C of Section 4 of Basic Data, OCWD Engineer's Report.

78 Table B-15 Monthly In-Lieu Recharge of Imported Water, 29-1 Month OCWD In-Lieu MWD In-Lieu (CUP*) Totals (af/mo) (af/mo) (af/mo) Jul-9 Aug-9 Sep-9 Oct-9 Nov-9 Dec-9 Jan-1 Feb-1 Mar-1 Apr-1 May-1 Jun-1 Totals *MWD Conjunctive Use Program

79 Table B-16 Annual Recharge by Source, 2-21 Fiscal Year (July-June) SAR Base Flow (1) Storm Flow/Local Water Total SAR and other Local Water (1) Total Imported/Purchas e Water Recycled Water Groundwater (2) Subtototal of OCWD Recharge (3) Incidental Recharge Total Recharge (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) ,915 28, ,794 88,357 1,63 8, ,22 5, , ,891 24,327 17,218 67,61 4,143 7, ,157 37, , ,113 49,98 195,211 18,553 3,867 5,78 313,339 57, , ,51 41, ,629 84,166 1,784 4,94 274,672 58, , ,37 8,72 234,379 86,732 4,155 2,92 328, , , ,736 89,97 236,833 17,286 4,341 1, ,629 38, , ,338 36,9 169,428 12, ,959 14, , ,9 6,67 184,76 9,887 18, ,789 46, , ,49 53,7 158,497 28, 54, ,17 69,352 31, ,599 61,35 163,634 21,586 66,56 251,726 83, ,965 Totals 1,356, ,392 1,88,381 74, ,69 29,678 2,774,65 615,3 3,389,949 1 year Avg. 135,699 52, ,38 7,498 15,961 2, ,465 61,53 338,995 Avg.Percent of Total 55% 21% 5% 1% 82% 18% (1) Recharge of SAR and other Local Water based on monthly reports prepared by OCWD Recharge Operations staff and may differ from what is reported by the SAR Watermaster. (2) Deep aquifer groundwater used for injection at the Talbert Barrier, which was stopped in August 26. (3) Recharge due to the activity of OCWD (aka Artificial Recharge).

80 Table B-17 Monthly Recharge Source Summary, 29-1 Local Water Imported/Purchased Water Recycled Water Month SAR Base Flow (1) Storm Flow/Local Water (2) Subtotal Local Water Surface Recharge Talbert Barrier Alamitos Barrier (3) In-Lieu Recharge Subtotal Import/Purchase Water Surface Recharge Talbert Barrier Alamitos Barrier (2) Subtotal Recycled Water Incidental Recharge (4) Grand Total (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) (af/mo) Jul-9 5, ,9 1, ,415 2,494 3, ,66 6,937 2,2 Aug-9 6,2 3 6,5 5, ,534 2,89 3, ,4 6,937 24,524 Sep-9 5,86 3 5, ,484 3, ,832 6,937 18,786 Oct-9 7, , ,55 3, ,871 6,937 2,773 Nov-9 7, , ,32 1, ,31 6,937 19,559 Dec-9 9,958 14,283 24, ,732 2, ,389 6,937 36,659 Jan-1 11,623 9,774 21, ,687 3, ,29 6,937 34,417 Feb-1 1,956 13,299 24, ,16 2, ,679 6,937 35,933 Mar-1 11,377 12,361 23,738 1, ,677 2,83 3, ,972 6,937 38,323 Apr-1 1,345 5,42 15,765 7, ,85 2,415 3, ,728 6,937 36,279 May-1 8,227 2,794 11,21 4, ,335 2,214 3, ,796 6,937 28,89 Jun-1 7,173 1,856 9, ,39 3, ,515 6,937 21,63 Totals 12,599 61,35 163,634 2, ,586 29,617 36, ,56 83, ,964 Note: (1) SAR base flow totals based on OCWD data unless otherwise noted (See Table B-5). (2) Storm flow/local water includes SAR storm flow originating above Prado Dam, local SAR inflow below Prado Dam, Santiago Creek inflow, precipitation to water surfaces. Storm flow totals only show what portion of storm flow that was captured and recharged. (3) Only that portion of Alamitos Gap Barrier recharge attributed to the Orange County groundwater basin is shown. (4) The annual estimated incidental recharge is divided evenly over the 12 months of the year.

81 Table B-18 Annual Recharge by Facility, 2-21 Fiscal Year (July-June) SAR Base Flow Storm Flow/Local Water Surface Water Recharge System Total SAR/Local Water (1) Imported/ Purchase Water Recycled Water Total Surface Water Recharge In-Lieu System Seawater Barrier System (2) Total OCWD Recharge (3) (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) (afy) ,915 28, ,794 67,14 249,897 18,64 12, , ,891 24,327 17,218 43,2 213,417 19,472 16, , ,113 49,98 195,211 44, ,362 61,463 12, , ,51 41, ,629 24,987 29,616 52,168 12, , ,37 8,72 234,379 4, ,757 69,617 19, , ,736 89,97 236,833 1, ,819 89,216 12, , ,338 36,9 169,428 44, ,575 5,74 8, , ,9 6,67 184,76 4,149 7, ,631 16, , ,49 53,7 158,497 22,237 25,248 25,982 35, , ,599 61,35 163,634 2,642 29, ,893 37, ,725 Totals 1,356, ,392 1,88, ,981 62,587 2,228, , ,382 2,774,649 1 year Avg. 135,699 52, ,38 28,598 6, ,895 36,132 18, ,465 Percent of Total 68% 1% % 8% 13% 7% (1) Recharge of SAR and other Local Water based on monthly reports prepared by OCWD Recharge Operations Staff. May differ from what is reported by the SAR Watermaster. (2) Only that portion of Alamitos Gap Barrier recharge attributed to the Orange County groundwater basin is shown. (3) This is recharge due solely to OCWD activities. Does not include incidental recharge.

82 Appendix C Monthly Forebay Percolation Efficiency Reports

83 FOREBAY PERCOLATION EFFICIENCY REPORT July-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 4, na 2, ,626 1, ,335 12,573 Remarks Average perc of 74 cfs estimated based on observations Includes Olive pit Includes Foster Huckleberry and Conrock basins No way to gage inflow, Included in Off river perc Inflow from MWD (OC-28) And Warner Basin All inflow from MWD (OC-28) Inflow from MWD (OC-28) and GWR All inflow from GWR No inflow Not in use No inflow Empty No inflow Not in use No inflow Not in use TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (Used Prado) 5,99 Est'd SAR flow past Chapman Ave. GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) 1,364.1 Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 Calc'd evap (inches) Estimated 8.17 Est'd local Santiago inflow 3 Est'd evaporative losses 5 34 Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 9,878 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 7,896 6,195-1,71 TOTAL INFLOW (TABLE 1) 9,878 Santiago Pits 8,37 6,972-1,335 TOTAL LOSSES (TABLE 2) 34 River STORAGE CHANGE 6 (TABLE 3) -3,36 Off-river CALC'D PERCOLATION 12, Irvine Lake TOTAL 16,23 13,167-3,36 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

84 PERCOLATION BASIN MONTHLY SUMMARY JULY 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,39 2,347 2,6 621 na na 236 Little Warner na na na na Olive Pit na na na na Anaheim Lake 1, ,3 2, Mini-Anaheim Lk na Miller Basin , Kraemer Basin ,5 1, La Jolla Basin.4. 2 Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit , Santiago (Bond) 5,594 4,815 8,69 1, Santiago (Blu Dia) 5 2,713 2,157 5,24 25 Deep Basin Totals 16,23 13,167 26,161 7,636 Prado Dam 6 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

85 FOREBAY PERCOLATION EFFICIENCY REPORT August-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 4, na 3, , ,888 Remarks Average perc of 76 cfs estimated based on observations Includes Olive pit Includes Foster Huckleberry and Conrock basins No way to gage inflow, Included in Off river perc Inflow from MWD (OC-28) And Warner Basin All inflow from MWD (OC-28) Inflow from MWD (OC-28) All inflow from GWR No inflow Not in use No inflow Empty No inflow Not in use No inflow Not in use TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (Used Prado) 6,2 Est'd SAR flow past Chapman Ave. GWRS 2,88.99 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) 5,438.1 Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 Calc'd evap (inches) Estimated 7.62 Est'd local Santiago inflow 3 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 14,297 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 6,195 6, TOTAL INFLOW (TABLE 1) 14,297 Santiago Pits 6,972 5,942-1,3 TOTAL LOSSES (TABLE 2) 318 River STORAGE CHANGE 6 (TABLE 3) -98 Off-river CALC'D PERCOLATION 14, Irvine Lake TOTAL 13,167 12, NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

86 PERCOLATION BASIN MONTHLY SUMMARY AUGUST 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,347 2,348 2,6 7 na na 235 Little Warner na na na na Olive Pit na na na na Anaheim Lake ,3 3, Mini-Anaheim Lk na Miller Basin , Kraemer Basin , La Jolla Basin.. 2 Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit 963 1,23 2, Santiago (Bond) 4,815 4,26 8, Santiago (Blu Dia) 5 2,157 1,736 5, Deep Basin Totals 13,167 12,259 26,161 9,945 Prado Dam 6 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

87 FOREBAY PERCOLATION EFFICIENCY REPORT September-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 4, na , ,9 Remarks Average perc of 8 cfs estimated based on observations Includes Olive pit Includes Foster Huckleberry and Conrock basins Dewatered Empty at months end Not in use Emptied for pump repair All inflow from GWR No inflow Not in use No inflow Empty No inflow Not in use No inflow From Santiago pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (Used Prado) 5,869 Est'd SAR flow past Chapman Ave. GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 Calc'd evap (inches) Estimated 6.31 Est'd local Santiago inflow 3 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 8,383 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 6,317 5,153-1,164 TOTAL INFLOW (TABLE 1) 8,383 Santiago Pits 5,942 5, TOTAL LOSSES (TABLE 2) 263 River STORAGE CHANGE 6 (TABLE 3) -1,888 Off-river CALC'D PERCOLATION 1,9 263 Irvine Lake TOTAL 12,259 1,371-1,888 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

88 PERCOLATION BASIN MONTHLY SUMMARY SEPTEMBER 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,348 2,534 2,6 817 na na 237 Little Warner na na na na Olive Pit na na na na Anaheim Lake 845 2, Mini-Anaheim Lk 21 na Miller Basin , Kraemer Basin 174 1, La Jolla Basin.. 2 Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit 1, , Santiago (Bond) 4,26 3,66 8, Santiago (Blu Dia) 5 1,736 1,558 5, Deep Basin Totals 12,259 1,371 26,161 4,936 Prado Dam 6 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

89 FOREBAY PERCOLATION EFFICIENCY REPORT October-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,346 Remarks Average perc of 86 cfs estimated based on observations Inflow above 5 coves dam Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Empty at months end Not in use Emptied for pump repair All inflow from GWR No inflow Not in use No inflow Empty No inflow Not in use No inflow From Santiago pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (Used Prado) 7,7 Est'd SAR flow past Chapman Ave. GWRS 2,54.84 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 1 Calc'd evap (inches) Estimated 4.85 Est'd local Santiago inflow 55 Est'd evaporative losses 5 22 Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches).7 Precip direct to open water surfaces 5 29 TOTAL INFLOW 1,389 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 5,153 5, TOTAL INFLOW (TABLE 1) 1,389 Santiago Pits 5,218 4, TOTAL LOSSES (TABLE 2) 22 River STORAGE CHANGE 6 (TABLE 3) -159 Off-river CALC'D PERCOLATION 1, Irvine Lake TOTAL 1,371 1, NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

90 PERCOLATION BASIN MONTHLY SUMMARY OCTOBER 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,534 2,557 2,6 886 na na 237 Little Warner na na na na Olive Pit na na na Anaheim Lake 2,3 168 Mini-Anaheim Lk 21 na Miller Basin , Kraemer Basin 1,5 164 La Jolla Basin.. 2 Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit , Santiago (Bond) 3,66 3,23 8, Santiago (Blu Dia) 5 1,558 1,543 5,24 23 Deep Basin Totals 1,371 1,212 26,161 4,434 Prado Dam 6 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

91 FOREBAY PERCOLATION EFFICIENCY REPORT November-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,44 Remarks Average perc of 86 cfs estimated based on observations Inflow above 5 coves dam Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Used 3 days Inflow from Little Warner GWR All inflow from GWR Inflow from Little Warner Not in use No inflow Includes Lincoln Basin Inflow from Santiago Inflow from Santiago No inflow From Santiago pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (Used Prado) 8,343 Est'd SAR flow past Chapman Ave. GWRS 2,31.79 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 5 Calc'd evap (inches) Estimated 3.89 Est'd local Santiago inflow 3 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 1,725 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 5,466 5,457-9 TOTAL INFLOW (TABLE 1) 1,725 Santiago Pits 4,746 3, TOTAL LOSSES (TABLE 2) 162 River STORAGE CHANGE 6 (TABLE 3) -877 Off-river CALC'D PERCOLATION 11, Irvine Lake TOTAL 1,212 9, NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

92 PERCOLATION BASIN MONTHLY SUMMARY NOVEMBER 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,557 2,434 2,6 816 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 74 2, na 174 Mini-Anaheim Lk na Miller Basin , Kraemer Basin 1, na La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit , Santiago (Bond) 3,23 2,578 8,69 48 na na 216 Santiago (Blu Dia) 5 1,543 1,3 5, Deep Basin Totals 1,212 9,335 26,161 5,148 Prado Dam , NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

93 FOREBAY PERCOLATION EFFICIENCY REPORT December-9 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,71 2, ,35 1, ,113 Remarks Average perc of 91 cfs estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Inflow from Anaheim pumps and Little Warner Inflow from Anaheim pumps and Little Warner All inflow from GWR Inflow from Anaheim pumps and Little Warner Not in use No inflow Includes Off River system and Lincoln Basin Inflow from SAR and Santiago Inflow from Burris and Santiago Inflow from Burris and Santiago Creek From Santiago and Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates 24,39 Est'd SAR flow past Chapman Ave. 1, GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 3 Calc'd evap (inches) Estimated 2.49 Est'd local Santiago inflow 45 Est'd evaporative losses 5 14 Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) 2.75 Precip direct to open water surfaces TOTAL INFLOW 27,987 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 5,457 7,518 2,61 TOTAL INFLOW (TABLE 1) 27,987 Santiago Pits 3,878 7,587 3,79 TOTAL LOSSES (TABLE 2) 1,14 River STORAGE CHANGE 6 (TABLE 3) 5,77 Off-river CALC'D PERCOLATION 21,113 1,14 Irvine Lake TOTAL 9,335 15,15 5,77 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

94 PERCOLATION BASIN MONTHLY SUMMARY DECEMBER 29 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,434 2,465 2,6 595 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 74 1,158 2,3 3, Mini-Anaheim Lk na Miller Basin , Kraemer Basin 75 1,5 2, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 825 1,521 2,67 1, Santiago (Bond) 2,578 5,177 8, na na 216 Santiago (Blu Dia) 5 1,3 2,41 5, Deep Basin Totals 9,335 15,15 26,161 12,616 Prado Dam , NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

95 FOREBAY PERCOLATION EFFICIENCY REPORT January-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 6, , ,224 1, ,2 1, , ,796 Remarks Average perc of 98 cfs Estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Inflow from Anaheim pumps and Little Warner Inflow from Anaheim pumps and LW and GWR Inflow from GWR and sidespill from Carbon Diversion Inflow from Anaheim pumps and Little Warner Not in use No inflow Includes Off River system and Lincoln Basin Inflow from SAR and Santiago Inflow from Burris and Santiago Inflow from Burris and Santiago Creek From Santiago and Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates 77, Est'd SAR flow past Chapman Ave. 58,5 GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 1,2 Calc'd evap (inches) Estimated 2.9 Est'd local Santiago inflow 1,4 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) 7.12 Precip direct to open water surfaces TOTAL INFLOW 82,584 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY 58,621 Deep basins 7,517 8,745 1,228 TOTAL INFLOW (TABLE 1) 82,584 Santiago Pits 7,587 11,526 3,939 TOTAL LOSSES (TABLE 2) 58,621 River STORAGE CHANGE 6 (TABLE 3) 5,167 Off-river CALC'D PERCOLATION 18,796 Irvine Lake TOTAL 15,14 2,271 5,167 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

96 PERCOLATION BASIN MONTHLY SUMMARY JANUARY 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,18 1,6 na na Warner Basin 2,465 2,53 2,6 446 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 1,158 1,217 2,3 2, Mini-Anaheim Lk na Miller Basin , Kraemer Basin ,5 1, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 1,521 2,238 2,67 1, Santiago (Bond) 5,177 7,349 8,69 2, Santiago (Blu Dia) 5 2,41 4,177 5,24 25 Deep Basin Totals 15,14 2,271 26,161 1,95 Prado Dam 6 8,74 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

97 FOREBAY PERCOLATION EFFICIENCY REPORT February-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , , , 1, , ,777 Remarks Average perc of 1 cfs Estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Inflow from Anaheim pumps and Little Warner Inflow from Anaheim pumps and LW and GWR Inflow from GWR Inflow from Anaheim pumps and Little Warner Not in use No inflow Includes Off River system and Lincoln Basin Inflow from SAR and Santiago Inflow from Burris and Santiago Inflow from Burris and Santiago Creek From Santiago and Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates estimated 47,5 Est'd SAR flow past Chapman Ave. 25, GWRS 2,15.59 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD). Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 7 Calc'd evap (inches) Estimated 2.87 Est'd local Santiago inflow 465 Est'd evaporative losses 5 12 Irvine lake releases (OC-13 MWD) Villa Park Dam releases 38 Precip at Warner Basin (inches) 5.3 Precip direct to open water surfaces 5 21 TOTAL INFLOW 51,36 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY 25,12 Deep basins 8,745 9, TOTAL INFLOW (TABLE 1) 51,36 Santiago Pits 11,526 12,991 1,465 TOTAL LOSSES (TABLE 2) 25,12 River STORAGE CHANGE 6 (TABLE 3) 2,464 Off-river CALC'D PERCOLATION 23,777 Irvine Lake TOTAL 2,271 22,735 2,464 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

98 PERCOLATION BASIN MONTHLY SUMMARY FEBRUARY 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3,4 1,18 1, 1,6 na na Warner Basin 2,53 2,441 2,6 387 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 1,217 1,696 2,3 3, Mini-Anaheim Lk na Miller Basin Kraemer Basin ,5 4, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 2,238 2,413 2,67 1, Santiago (Bond) 7,349 8,47 8,69 5, Santiago (Blu Dia) 5 4,177 4,944 5, Deep Basin Totals 2,271 22,735 26,161 16,868 Prado Dam 6 8,74 13,685 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

99 FOREBAY PERCOLATION EFFICIENCY REPORT March-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,55 2, , , ,599 Remarks Average perc of 92 cfs Estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Inflow from Little Warner and OC-28 Inflow from Little Warner and OC-28 Inflow from GWR Inflow from Little Warner and OC-28 Not in use No inflow Includes Off River system and Lincoln Basin Inflow from SAR Inflow from Burris Inflow from Burris and Santiago Creek From Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates estimated 26,5 Est'd SAR flow past Chapman Ave. 3, GWRS 2,83.29 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) 1,612.3 Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 1 Calc'd evap (inches) Estimated 4.89 Est'd local Santiago inflow 113 Est'd evaporative losses 5 24 Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches).59 Precip direct to open water surfaces 5 25 TOTAL INFLOW 31,18 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 9,744 1, TOTAL INFLOW (TABLE 1) 31,18 Santiago Pits 12,991 13,99 18 TOTAL LOSSES (TABLE 2) 3,24 River STORAGE CHANGE 6 (TABLE 3) 377 Off-river CALC'D PERCOLATION 27,599 3,24 Irvine Lake TOTAL 22,735 23, NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

100 PERCOLATION BASIN MONTHLY SUMMARY MARCH 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3,4 1, 885 1,6 na na Warner Basin 2,441 2,512 2,6 59 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 1,696 1,944 2,3 3, Mini-Anaheim Lk na Miller Basin , Kraemer Basin ,5 4, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 2,413 2,515 2,67 1, Santiago (Bond) 8,47 8,98 8,69 6, Santiago (Blu Dia) 5 4,944 5,1 5, Deep Basin Totals 22,735 23,112 26,161 2,18 Prado Dam 6 13,685 6,17 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

101 FOREBAY PERCOLATION EFFICIENCY REPORT April-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,273 2, , , ,54 Remarks Average perc of 85 cfs Estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Inflow from Little Warner Inflow from Little Warner Inflow from Little Warner and OC-28 Inflow from Little Warner and OC-28 Inflow from GWR and OC-28 Inflow from Little Warner and OC-28 Not in use No inflow Includes Off River system and Lincoln Basin Inflow from SAR Inflow from Burris Inflow from Burris and Santiago Creek From Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates estimated 15,596 Est'd SAR flow past Chapman Ave. GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) 7,77.3 Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 1 Calc'd evap (inches) Estimated 4.89 Est'd local Santiago inflow 113 Est'd evaporative losses 5 24 Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches).59 Precip direct to open water surfaces 5 25 TOTAL INFLOW 26,37 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 1,13 1, TOTAL INFLOW (TABLE 1) 26,37 Santiago Pits 13,99 13, TOTAL LOSSES (TABLE 2) 24 River STORAGE CHANGE 6 (TABLE 3) 587 Off-river CALC'D PERCOLATION 25, Irvine Lake TOTAL 23,112 23, NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

102 PERCOLATION BASIN MONTHLY SUMMARY APRIL 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,512 2,512 2,6 59 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 1,944 1,944 2,3 3, Mini-Anaheim Lk na Miller Basin , Kraemer Basin ,5 3, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 2,515 2,463 2,67 1, Santiago (Bond) 8,98 8,22 8,69 5, Santiago (Blu Dia) 5 5,1 5,119 5, Deep Basin Totals 23,112 23,699 26,161 18,187 Prado Dam 6 13,685 6,17 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. "na" indicates data not available.

103 FOREBAY PERCOLATION EFFICIENCY REPORT May-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , , , ,964 Remarks Average perc of 84 cfs Estimated based on observations See 5 coves value Includes Foster Huckleberry and Conrock basins Empty Inflow from Little Warner and OC-28 Inflow from Little Warner and OC-28 Dewatered Inflow from GWR, OC-28 and Little Warner Inflow from Little Warner and OC-28 Not in use Inflow from Little Warner and OC-28 Used for only 13 days. Off river included Inflow from SAR Inflow from Burris Inflow from Burris and Santiago Creek From Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (used PRADO data) 1,961 Est'd SAR flow past Chapman Ave. GWRS 2, OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) 4,287.1 Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 Calc'd evap (inches) Estimated 6.41 Est'd local Santiago inflow 6 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 17,522 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 1,474 7,955-2,519 TOTAL INFLOW (TABLE 1) 17,522 Santiago Pits 13,321 12,131-1,19 TOTAL LOSSES (TABLE 2) 267 River STORAGE CHANGE 6 (TABLE 3) -3,79 Off-river CALC'D PERCOLATION 2, Irvine Lake TOTAL 23,795 2,86-3,79 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

104 PERCOLATION BASIN MONTHLY SUMMARY MAY 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,516 2,578 2,6 73 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 2,123 2,239 2,3 2, Mini-Anaheim Lk na Miller Basin , Kraemer Basin 963 1, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins na na na Burris Pit 2, , Santiago (Bond) 8,22 7,643 8,69 5, Santiago (Blu Dia) 5 5,119 4,488 5, Deep Basin Totals 23,795 2,86 26,161 14,662 Prado Dam 6 4,644 1,854 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. 7) All numbers in red estimated. "na" indicates data not available.

105 FOREBAY PERCOLATION EFFICIENCY REPORT June-1 RIVER SYSTEM DESILTING SYSTEM OFF-RIVER SYSTEM WARNER SYSTEM 1 OLIVE BASIN 2 ANAHEIM LAKE MINI-ANA LAKE KRAEMER BASIN MILLER BASIN LA JOLLA BASIN PLACENTIA BASIN 3 RAYMOND BASIN 3 FIVE COVES BASIN BURRIS BASIN RIVER VIEW BASIN SANTIAGO BASINS SANTIAGO CREEK TOTALS Actual 5, , ,776 2, , ,176 Remarks Average perc of 85 cfs Estimated based on observations Used only 2 days Includes Foster Huckleberry and Conrock basins Empty Inflow from Little Warner and OC-28 Inflow from Little Warner and OC-28 Dewatered Inflow from GWR, OC-28 and Little Warner Inflow from Little Warner and OC-28 Not in use Inflow from Little Warner and OC-28 Empty Inflow from SAR Inflow from Burris Inflow from Burris and Santiago Creek From Burris pumps TABLE 1 AVAILABLE FLOWS TO RECHARGE SYSTEMS (AF) Imperial Headgates (used PRADO data) 8,969 Est'd SAR flow past Chapman Ave. GWRS 2,39.15 OC-11 (MWD) Est'd Santiago Cr. flow to SAR OC-28 (MWD) Est'd flows past Raymond Basin OC-28a (MWD) Est'd local Forebay inflow below Imperial 4 Calc'd evap (inches) Estimated 6.41 Est'd local Santiago inflow 6 Est'd evaporative losses Irvine lake releases (OC-13 MWD) Villa Park Dam releases Precip at Warner Basin (inches) Precip direct to open water surfaces 5 TOTAL INFLOW 11,125 TOTAL LOSSES TABLE 3 STORAGE CHANGES (AF) Facility Begin End Net TABLE 2 LOSSES FROM RECHARGE SYSTEM (AF) SUMMARY Deep basins 7,955 6,569-1,386 TOTAL INFLOW (TABLE 1) 11,125 Santiago Pits 12,131 9,198-2,933 TOTAL LOSSES (TABLE 2) 267 River STORAGE CHANGE 6 (TABLE 3) -4,319 Off-river CALC'D PERCOLATION 15, Irvine Lake TOTAL 2,86 15,767-4,319 NOTES: 1) Warner system includes est monthly perc values for Foster-Huckleberry and Conrock basins. 2) No instrumentation in Olive Basin; perc estimated. 3) Placentia and Raymond are County of Orange RDMD flood control basins. 4) Carbon Diversion included. 5) Estimated Precipitation and Evaporation is based on 5 acres of open water surface. 6) Net "negative" storage is water volume moving from basins to underground recharge.

106 PERCOLATION BASIN MONTHLY SUMMARY JUNE 21 (values in acre-feet) Facility Storage Storage Maximum Total Max Avg Avg W.S. 1 Start End Storage Perc Perc Perc Elev Desilting Ponds 2, Fos-Huckleberry 2, na na Conrock Basin 3, ,6 na na Warner Basin 2,578 2,426 2,6 831 na na Little Warner na na na na Olive Pit na na na Anaheim Lake 2,239 1,374 2,3 1, Mini-Anaheim Lk na Miller Basin , Kraemer Basin 47 1,5 1, La Jolla Basin Placentia Basin na Raymond Basin na Five Coves Basins 7 na na na Burris Pit , Santiago (Bond) 7,643 6,16 8,69 2, Santiago (Blu Dia) 5 4,488 3,92 5, Deep Basin Totals 2,86 15,767 26,161 9,546 Prado Dam 6 1,854 25, NOTES: 1) "Avg W.S." is feet above Mean Sea Level. 2) Some values estimated where lack of instrumentation precludes calculation. 3) Warner system includes Foster-Huckleberry and Conrock basins. 4) Periodic discharge from YLCWD's well #11 into Conrock Basin unaccounted for. 5) Storage in Blu Dia includes Smith Pit. Above elev 235, Santiago Pits respond as one basin. 6) Prado dam storage values provided by U.S. Army Corps of Engineers. 7) All numbers in italics estimated. "na" indicates data not available.

107 Orange County Water District P.O. Box 83 Fountain Valley, CA Tel: (714) Fax: (714)