4.4 Water Resources and Flooding

Transcription

1 This section of the Hoop Structures Ordinance Amendment (Project) Environmental Impact Report (EIR) addresses potential impacts associated with flooding and water resources. This analysis is based on a number of resources including the Santa Barbara County Groundwater Report (2012), the County Comprehensive Plan, the Cannabis Land Use Ordinance and Licensing Draft Program EIR, and other sources cited herein Existing Conditions The watershed basins in the inland, unincorporated areas of the County of Santa Barbara (County) provide essential supplies of water to the community for biological resources and residential, industrial, and agricultural use. A discussion of the surface water and groundwater basins and storm water flow is provided below. a. Surface Water The County of Santa Barbara 2013 Final Integrated Regional Water Management (IRWM) Plan, which is the most recent IRWM Plan, classifies four major watersheds in the County. These include the Santa Maria Watershed, which includes the Cuyama and Sisquoc watersheds, San Antonio Creek Watershed, Santa Ynez River Basin Watershed, and the South Coast Watersheds. Each watershed is comprised of sub-watershed basins associated with specific drainages. Many rivers and creeks make up the surface water that drains these watersheds. Abundance of surface water varies from region to region, depending on precipitation and water use. For example, some areas, such as the agricultural area of Tepusquet, receive very little surface waters, while the City of Buellton receives plenty of surface waters from the Santa Ynez River. The County of Santa Barbara 2011 Groundwater Report (County of Santa Barbara 2012) also provides a detailed account of more of the County s important watersheds. The watersheds associated with the Project are listed in Table and shown in Figure below, along with the major surface waters that drain these watersheds

2 Source: Watershed Environmental UV 166 UV 166 P a c i f i c Ocean Project Area Santa Barbara County Boundary Coastal Zone Guadalupe UV 1 Santa Maria US 101 Santa Maria Valley Cuyama Valley UV 166 UV 33 Regions Cuyama Valley Lompoc Valley UV 1 UV 135 Santa Maria Valley Santa Ynez Valley South Coast/Gaviota Watersheds (Watershed Environmental) Cuyama River Lower Santa Ynez Middle Santa Ynez Orcutt Creek Lompoc UV 246 UV 1 Lompoc Valley US 101 Buellton Solvang Santa Ynez Valley UV 246 UV 154 San Antonio Creek Santa Clara River Santa Maria River Shuman Creek Sisquoc River US 101 South Coast/Gaviota South Coast Upper Santa Ynez Ventura River 0 Miles 5[ UV 217 Santa Barbara UV 192 US 101 Carpinteria M:\JOBS5\8855\common_gis\Fig4.4-1.mxd 1/19/2018 fmm FIGURE County of Santa Barbara Watersheds

3 Watershed Region Table 4.4-1: Surface Waters in Santa Barbara County Major Surface Waters South Coast Surface waters in the South Coast/Gaviota Region are comprised of a number of smaller creeks. Major drainages include Rincon, Carpinteria, Franklin, Santa Monica, and Toro Canyon Creeks in Carpinteria; Cold Springs, Hot Springs, San Ysidro and Romero Creeks in Montecito; Sycamore, Mission, San Roque and Arroyo Burro Creeks in Santa Barbara; Cieneguitas, Arroyo Burro and San Roque Creeks in Foothill; and Atascadero, Maria Ygnacio, San Jose, Tecolotito, and San Pedro Creeks in Goleta. Jalama Creek, Canada De La Gaviota, Canada Del Refugio, Canada Del Capitan, Dos Pueblos Canyon Creek, Tecelote Creek, and Glen Annie Canyon also drain this watershed. Many of these surface waters drain into the Pacific Ocean. Cuyama River The Cuyama River drains the Cuyama Valley Watershed to the Twitchell Reservoir. Salisbury Creek is also included in this watershed. Upper Santa Ynez The Upper Santa Ynez Watershed is primarily drained by the Santa Ynez River. The Santa Ynez River is 75 miles long and drains the north slope of the Santa Ynez Mountains, the south slope of the San Rafael Mountains, and much of the southern half of Santa Barbara County. Smaller drainages include Alder Creek and Rancho Nuevo Creek. Middle Santa Ynez The Santa Ynez River is the major drainage of the Middle Santa Ynez Watershed and is interrupted by Lake Cachuma. Smaller drainages such as Santa Cruz Creek and Cachuma Creek also drain into Lake Cachuma. Lower Santa Ynez While the Santa Ynez River is a major drainage in this watershed, other drainages include Alamo Pintado Creek, Santa Rosa Creek, San Miguelito Creek, and Salsipuedes Creek. Additionally, Zaca Creek and Zanja de Cota Creek both drain into the Santa Ynez River. San Antonio Creek The watershed is drained westerly by the San Antonio Creek and discharges into the San Antonio Lagoon at the Pacific Ocean. Sisquoc River The Sisquoc River, immediately east of Santa Maria, drains this watershed before joining with the Cuyama River into the Santa Maria River. Shuman Creek This watershed is drained westerly by Shuman Canyon Creek and Casmalia Canyon Creek. Santa Maria River The Santa Maria River Hydrologic Area includes all areas tributary to the Santa Maria River. The Santa Maria River is formed by the confluence of the Cuyama and Sisquoc approximately 7 miles east-southeast of Santa Maria. Orcutt Creek Orcutt Creek Watershed is drained by Orcutt Creek, Guadalupe Lake, Santa Maria River, and Greene Valley River. Santa Clara River Sespe Creek, a tributary of the Santa Clara River, originates within the boundaries of Santa Barbara County. Ventura River Matalija Creek originates in the Los Padres National Forest, within the boundaries of Santa Barbara County, before draining into Ventura River. Source: County of Santa Barbara 2012; State Water Resources Control Board (SWRCB)

4 b. Groundwater Groundwater supplies approximately 77 percent of the County s domestic, commercial, industrial, and agricultural water. Groundwater monitoring results have shown water level fluctuations that correlate with varying weather patterns of the area s semi-arid climate, with water levels generally increasing in years of higher precipitation and decreasing in drier years (County of Santa Barbara 2016d). As described further below, the groundwater basins in the County are generally in overdraft condition, although a few are in equilibrium or surplus (Table 4.4-2). Groundwater basin locations within the County are shown in Figure Causes of overdraft in these basins are likely due to agricultural, municipal, and industrial uses. Within the Project area, however, agricultural uses are the greatest contributors to groundwater usage. Groundwater Basin(s) Table 4.4-2: Status of Groundwater Basins in the Project Area Available Water in Storage 1 Annual Draw 1 Status Basin Priority 2 Carpinteria 16,000 3, Very Low Montecito 16, Very Low Foothill 5,000 1, Very Low Goleta 70,000 4,000 Overdraft Medium Santa Ynez River Valley 1,314,000 42,000 Overdraft Medium San Antonio 800,000 15,000 Overdraft Medium Santa Maria 1,100, ,000 Overdraft High Cuyama 1,500,000 65,000 Overdraft Medium Source: County of Santa Barbara 2014a; California Department of Water Resources All amounts listed are in acre-feet. 2 As a part of the California Statewide Groundwater Elevation Monitoring (CASGEM) Program, the California Department of Water Resources created the CASGEM Groundwater Basin Prioritization statewide ranking system to prioritize California groundwater basins in order to help identify, evaluate, and determine the need for additional groundwater level monitoring. In 2009, the Legislature passed Senate Bill X7-6, which establishes collaboration between local monitoring parties and the California Department of Water Resources (DWR) to collect groundwater elevations statewide and that this information be made available to the public. In accordance with this amendment to the Water Code, the DWR created the CASGEM Program, to establish a permanent, locally managed program of regular and systematic monitoring in all of California's alluvial groundwater basins. The CASGEM program relies on the many established local long-term groundwater monitoring and management programs throughout the state. DWR works cooperatively with local entities to coordinate the CASGEM program, to maintain the collected elevation data in a readily and widely available public database, and to continue its current network of groundwater monitoring as funding allows

5 Source: County of Santa Barbara 2017 UV 166 P a c i f i c Ocean Project Area Santa Barbara County Boundary Coastal Zone Regions Cuyama Valley Lompoc Valley Guadalupe UV 1 UV 166 Santa Maria US 101 Santa Maria Valley UV 166 Cuyama Valley UV 166 UV 33 Santa Maria Valley Santa Ynez Valley South Coast/Gaviota UV 1 UV 135 Groundwater Basins (County of Santa Barbara, 2017) Buellton Uplands Carpinteria Cuyama Valley Goleta Lompoc Plain Lompoc Terrace Lompoc Uplands Montecito San Antonio Lompoc UV 246 UV 1 Lompoc Valley UV 1 US 101 Santa Ynez Valley Buellton Solvang UV 246 UV 154 US 101 South Coast/Gaviota Santa Barbara Santa Maria Santa Ynez River Santa Ynez Uplands 0 Miles 5[ US 101 UV 217 UV 154 US 101 Santa Barbara UV 192 US 101 Carpinteria M:\JOBS5\8855\common_gis\Fig4.4-2.mxd 1/19/2018 fmm FIGURE County of Santa Barbara Groundwater Basins

6 The Santa Barbara County Water Agency (SBCWA) also currently monitors 283 wells for depth to groundwater and 27 of these wells for water quality in cooperation with the United States Geological Survey (USGS). These monitoring wells are generally located in unincorporated areas of the County. Individual water districts and municipalities monitor many more wells in their service areas, although there are no recently published groundwater reports that indicate existing groundwater levels. The most recent reports rely on data from between 1992 and In addition to groundwater reports, several public agencies within the County have adopted or drafted groundwater management plans for their respective basins. The basins within Santa Barbara County with adopted groundwater management plans include Carpinteria, Montecito, Foothill, and Buellton Uplands. The County Water Agency is serving as the groundwater sustainability agencies (GSA) for the non-adjudicated fringe areas of the Santa Maria and Goleta Groundwater Basins. In addition to groundwater management plans, water resources are evaluated by the County on a project-by-project basis, using the Environmental Thresholds and Guidelines Manual, which describes the adopted County methodology for estimating the safe yield of bedrock aquifers. The County maintains historical data for salinity and nitrate concentration from monitoring wells for each of the groundwater basins in its 2011 Groundwater Report (County of Santa Barbara 2012). Historically, high nitrate concentrations have been documented within several of the groundwater basins within the County. Additionally, elevated sulfate and/or chloride concentrations impact some regions of the groundwater basins in the County. Point sources of sulfates and nitrates include sewage treatment plants, industrial discharges, and agricultural return flows. While sulfates are not considered toxic to plants or animals at normal concentrations, concentrations of 500 to 750 milligrams per liter may cause a temporary laxative effect in humans. Sulfates can also form strong acids and change the ph characteristics of a water body. Chloride concentrations are a particular problem in low-lying areas of the basin near tidal marshes, and are an indication of seawater intrusion (County of Santa Barbara 2012). SANTA MARIA VALLEY REGION GROUNDWATER BASINS San Antonio The San Antonio Groundwater Basin underlies the San Antonio Valley, in the southern part of the Santa Maria Valley Region, which consists mainly of agriculture, ranching, and a small amount of urban development in the town of Los Alamos. Oil development is also present within the valley. The area experiences average annual rainfall of about 15 inches. Water supply from the basin comes entirely from groundwater, as there are no surface diversions. Agriculture and Vandenberg Air Force Base (AFB) are the two largest users of water from this basin. The foothill area is used primarily for dry farming, vineyards, or grazing, while the flatlands are utilized for irrigated farming. The crops grown include truck crops, wine grapes, sugar beets, beans, corn, alfalfa, and ornamentals (County of Santa Barbara 2009b). The Vandenberg AFB boundary overlies the westernmost portion of 4.4-6

7 the basin and uses groundwater in addition to State Water Project supplies, which are pumped to Vandenberg AFB. Water quality studies in the late 1970s indicated that salinity concentrations generally increase in a westward direction, toward the ocean along the valley floor. The cause of the westward water quality degradation has been thought to be the accumulation of lower quality water from agricultural return flow and the dissolution of soluble minerals. There is no evidence of seawater intrusion in the basin, nor is the basin considered susceptible to seawater intrusion due to the consolidated rock that separates the basin from the ocean (County of Santa Barbara 2012). Santa Maria The Santa Maria Groundwater Basin Main Unit is a 170-square-mile alluvial basin, bordering the San Antonio Basin to the south. The basin underlies an area that includes two cities (Santa Maria and Guadalupe); the unincorporated community of Orcutt; smaller towns such as Betteravia, Sisquoc, and Gary; extensive irrigated agriculture; and petroleum production. Additionally, a portion of this groundwater basin is located in San Luis Obispo County. Agriculture is the predominant land use in the basin, with a wide range of cultivation including broccoli, alfalfa, wine grapes, strawberries, ornamental crops, and artichokes (County of Santa Barbara 2012). Oil development is extensive in the North County, particularly in the foothills and mountains where impacts to the groundwater basin are minor or nonexistent. Average rainfall varies from about 12 to 16 inches per year within the basin. Consolidated rocks form the basement unit of this basin. While primarily non-water-bearing, this basement unit does yield some water locally, generally only through fractures. The basin provides significant water supplies, with a net safe yield of 80,000 acre-feet per year (AFY) and existing use of 87,500 AFY since the City of Santa Maria transitioned to State Water Project supply and reduced their groundwater use (withdrawals were previously 100,000 AFY; County of Santa Barbara 2012). Tepusquet The Tepusquet area is a relatively small agricultural region in northern Santa Barbara County, approximately 12 miles east of the City of Santa Maria. According to the Agricultural Element of the County Comprehensive Plan, many of the foothills of this area are used for the cultivation of wine grapes. Additionally, at least an estimated 12 sites are currently used for cannabis cultivation within this area, with the total number of illegal grows noted by local residents unknown. While the Tepusquet area is mainly agricultural, there is little groundwater and precipitation received within the area. Most of the water used for agricultural activities comes from limited, fragmented groundwater resources and surface runoff. LOMPOC VALLEY REGION GROUNDWATER BASINS The Lompoc Valley groundwater basins consist of three hydrologically connected areas, which are further described below: the Lompoc Plain, Lompoc Terrace, and the Lompoc Uplands. The major population center within the region is the City of Lompoc, with the 4.4-7

8 smaller unincorporated communities of Vandenberg Village and Mission Hills to the north, as well as Vandenberg AFB. The primary land use in the valley is agriculture, and the economy is largely supported by truck farming and associated food processing and flower raising. The oil industry has developed a number of oil fields along the margins of the basin and a large amount of water is used during the oil recovery operations. Additionally, mining and processing on diatomite mines within the basin use a significant amount of groundwater (County of Santa Barbara 2012). Lompoc Plain The Lompoc Plain surrounds the lower reaches of Santa Ynez River and is bordered on the north by the Purisima Hills, on the east by the Santa Rita Hills, on the south by the Lompoc Hills, and on the west by the Pacific Ocean. This alluvial area is divided into an upper and a lower aquifer. Orographic rainfall of 18 inches occurs near the southern edge of the area in the Lompoc Hills, while the minimum precipitation of 10 inches falls near the Pacific Ocean. Rainfall averages about 12 inches per year over the entire Lompoc Plain. Groundwater in the Plain consists largely of a mixture of water from irrigation return and rainfall infiltration (County of Santa Barbara 2012). During periods of dry climate, water is released from Lake Cachuma to recharge groundwater levels in the eastern portion of the Plain. As such, this area is essentially in equilibrium (County of Santa Barbara 2012). Lompoc Terrace The Lompoc Terrace is situated between the Lompoc Plain to the east and the Pacific Ocean to the west, and is formed by a down-faulted block topped with permeable sediments on Vandenberg AFB, south of the Lompoc Plain. Thickness of the formation in the terrace is 400 to 500 feet. Historically, Vandenberg AFB used this area for water supply, but has relied upon State Water as well as water imported from the San Antonio Groundwater Basin. Climate in the area is heavily influenced by the nearby Pacific Ocean s cool air masses and rainfall averages 12 inches per year (County of Santa Barbara 2012). Lompoc Uplands The Lompoc Uplands is bordered on the west by the Burton Mesa, on the north by the Purisima Hills, on the east by a topographic divide which separates it from the Buellton Uplands Basin, and on the south by the Lompoc Plain and the Santa Rita Hills. Historically, underflow from the Lompoc Uplands and Lompoc Terrace contributed to recharge of the Lompoc Plain. Due to a long-term decline in water levels, underflow often now moves to the Western and Central Lompoc Uplands from the Lompoc Plain. The Lompoc Uplands Area provides water to the communities of Vandenberg Village and Mission Hills. The Santa Rita Subarea is the easternmost section of the basin (County of Santa Barbara 2012)

9 SANTA YNEZ VALLEY REGION GROUNDWATER BASINS Santa Ynez Uplands Santa Ynez Uplands Groundwater Basin underlies 130 square miles located about 25 miles east of Point Arguello and north of the Santa Ynez River. There are four towns located within the basin: unincorporated Santa Ynez, Los Olivos, and Ballard, and the City of Solvang. Scattered residential development, including small farms and ranchettes, prevail outside these towns, with larger farms and ranches beyond the smaller farms. Although human population is increasing in the area, agriculture is still the dominant land use. Agricultural production covers a wide range, including wine grapes, truck crops, field crops, cattle grazing, and thoroughbred horse farms (County of Santa Barbara 2012). Average rainfall within the basin varies from a maximum of about 24 inches per year in the higher elevations to a minimum of about 15 inches per year in the southern and central areas, with rainfall and stream seepage representing the primary sources of recharge to the basin. Groundwater supplies about 85 percent of the water demand within the basin. In addition, water is imported into the basin from the Cachuma Project 1, the State Water Project, and the Santa Ynez River Alluvial Basin. Agriculture accounts for about 75 percent of the water demand within the basin; the remaining demand is mostly from domestic consumers. Water quality within the basin is generally adequate for most agricultural and domestic purposes (County of Santa Barbara 2012). Santa Ynez Alluvial The Santa Ynez River Alluvial Groundwater Basin extends 36 miles from the Bradbury Dam to the Lompoc Plain and consists of the unconsolidated sand and gravel alluvial deposits of the Santa Ynez River. These deposits can be up to 150 feet thick and several hundred feet across. Groundwater in the Alluvial Groundwater Basin is influenced directly from surface flow of the river. Inflow to the basin comes from infiltration of river flow, direct percolation from rainfall, underflow from the Santa Ynez Uplands and Buellton Uplands Basins, and percolation from wastewater ponds in Solvang and Buellton. Existing requirements included in SWRCB Water Rights Decisions demand that water is released from Cachuma Reservoir to recharge the Alluvial Basin based on water levels in monitoring wells and credits of water held in reservoir storage. In addition, small amounts of recharge to the Santa Ynez River Alluvial Groundwater Basin can occur when water is released from Lake Cachuma to the riverbed for Endangered Species Act purposes under certain hydrological conditions detailed in the Biological Opinion for the U.S. Bureau of Reclamation Operation and Maintenance of the Cachuma Project. As such, the Cachuma Project may control basin water levels at certain times. Both public and private entities extract water from this basin, primarily for municipal and agricultural uses (County of Santa Barbara 2012). Buellton Uplands The Buellton Uplands Groundwater Basin encompasses about 29 square miles located about 18 miles east of the Pacific Ocean and directly north of the Santa Ynez River. The 4.4-9

10 community of Buellton occupies about 1,000 acres near the southeastern corner of the Buellton Uplands Basin and includes residential and commercial land uses. The remainder of the basin is dominated by agriculture including horse ranches and field crops (County of Santa Barbara 2012). The Buellton Uplands Basin receives little groundwater recharge from the Santa Ynez River even though it overlies a portion of the basin. Recharge to the basin is from deep percolation of rainfall, stream seepage, return flow from agriculture, and underflow from adjacent basins. This area experiences average annual rainfall of about 17 inches per year. This basin is considered to be in a state of surplus with natural recharge exceeding pumpage by a net of 800 AFY. This surplus represents the amount of groundwater from the Buellton Uplands Basin that discharges annually into the Santa Ynez River Riparian Basin. Approximately 80 percent of the 2,599 AFY of pumpage in the basin is attributable to agricultural irrigation. The City of Buellton and scattered farmsteads around the rural area use the remaining 20 percent. The importation of State Water has further reduced the reliance on groundwater. Water quality data for the basin is limited (County of Santa Barbara 2012). SOUTH COAST/GAVIOTA REGION GROUNDWATER BASINS Carpinteria The Carpinteria Groundwater Basin underlies approximately 12 square miles in the Carpinteria Valley and extends east of the County line into Ventura County. While the City of Carpinteria is the largest population center in the basin, there are scattered pockets of residential development outside the city. Agriculture is the dominant feature in the valley with crops including avocado, lemon, and walnut orchards, ornamental nurseries, and irrigated crops. There are also numerous greenhouses currently utilized for the cut flower and cannabis cultivation industries (County of Santa Barbara 2012). Precipitation in the basin varies with elevation. Near the coast, rainfall averages about 16.6 inches per year, but increases to about 24 inches per year on the south flank of the Santa Ynez Mountains. The basin contains two groundwater storage units separated by the Rincon Creek thrust fault. Storage Unit #1 consists of four distinct aquifers, which are hydrologically connected. One is within the Carpinteria Formation and three are within the Casitas Formation. In Storage Unit #2, the main source of water is the Santa Barbara Formation. The Casitas Formation is generally considered the principal source of groundwater in the basin. The primary drainages through which surface water empties into the Pacific Ocean are Rincon Creek, Carpinteria Creek, Franklin Creek, Santa Monica Creek, and Toro Canyon Creek. Besides groundwater, imported surface water from the State Water Project, which is further described below, and local surface water from Lake Cachuma are the other sources of water available to the basin (County of Santa Barbara 2012). Montecito The Montecito Groundwater Basin encompasses an estate residential community of about 6.7 square miles between the Santa Ynez Mountains and the Pacific Ocean in the southern

11 part of the County. While agricultural use is limited, there are scattered avocado and citrus orchards across the basin. It is separated from the Carpinteria Groundwater Basin to the east by faults and bedrock, from the Santa Barbara Groundwater Basin to the west by a topographical divide, and to the south by the Montecito Fault. The primary aquifer in the basin is the Casitas Formation (County of Santa Barbara 2012). The basin is drained by several small creeks that flow from the Santa Ynez Mountains south to the Pacific Ocean. These creeks include Cold Springs, Hot Springs, San Ysidro, and Romero. Average precipitation within the basin ranges from about 18 inches per year near the coast to about 25 inches per year in the foothills of the Santa Ynez Mountains (County of Santa Barbara 2012). Santa Barbara The Santa Barbara Groundwater Basin underlies an area of about 9 square miles situated between the Montecito and the Foothill Groundwater Basins. Geologic faults define the borders of the basin and impede the flow of groundwater on its north, northwest, and southwest sides, as well as the Pacific Ocean to the south. The basin includes two hydrologic units, approximately 7 and 2.5 square miles in size, respectively, which are separated by the Mesa Fault. The primary aquifer in the Santa Barbara Groundwater Basin is the Santa Barbara Formation, which is generally comprised of marine sands, silts, and clays. The main drainages that traverse the basin are Sycamore, Mission, San Roque, and Arroyo Burro creeks. All of these creeks flow intermittently in their lower reaches where the surface water percolates into the unconsolidated deposits (County of Santa Barbara 2012). Annual rainfall within the Santa Barbara Basin varies with altitude and averages about 18 inches near the coast and up to about 21 inches in the higher elevations of the foothills of the Santa Ynez Mountains. The major sources of recharge are infiltration of precipitation, seepage from streams, subsurface inflow from consolidated rocks, and infiltration of return flows of water imported to the City (Santa Barbara County 2012). Foothill The Foothill Groundwater Basin encompasses about 4.5 square miles of primarily residential development along the south coast of the County. Avocado and lemon orchards are present along the northern edge of the basin (County of Santa Barbara 2012). The borders of the Foothill Groundwater Basin extend from the underlying tertiary bedrock formations on the north to the Modoc Fault and Goleta Fault on the west, the More Ranch and the Mission Ridge Faults on the south, and bedrock on the east. The Santa Barbara Formation, which consists of marine sand, silt, and clay, is the principal aquifer of the basin. Surface drainage in the basin occurs via the Cieneguitas, Arroyo Burro, and San Roque creeks (County of Santa Barbara 2012). Recharge to the Foothill Basin occurs as stream seepage, infiltration of precipitation, and subsurface inflow from consolidated rocks of the Santa Ynez Mountains (County of Santa Barbara 2012)

12 Goleta The Goleta Groundwater Basin encompasses the Goleta Valley, a principally urbanized area that includes the incorporated City of Goleta and the unincorporated Eastern Goleta Valley, west of Santa Barbara along the south coast. Historically, agriculture was the dominant land use but has declined significantly over the last 30 years. The basin, about 8 miles long and 3 miles wide, lies directly west of the Santa Barbara and Foothill Groundwater Basins on County of Santa Barbara's South Coast. This basin is divided into three Sub-basins: the Central Sub-basin, the West Sub-basin, and the North Sub-basin (County of Santa Barbara 2012). The majority of available groundwater is within the North-Central Sub-basin. Underlying the unconsolidated water bearing sediments are the consolidated rocks which form the basement unit. Although this unit is primarily nonwater-bearing, it does yield water locally, generally through fractures (County of Santa Barbara 2012). Average rainfall within the basin ranges from about 16 inches per year at the coast to about 20 inches per year at the basin's highest elevation in the foothills of the Santa Ynez Mountains. Goleta is an alluvial plain, bordered by the Santa Ynez Mountains to the north and the Pacific Ocean to the south. Surface water drains south toward the Goleta Slough through several creeks which eventually empty into the ocean, including the Atascadero, Maria Ygnacio, San Jose, Tecolotito, and San Pedro creeks (County of Santa Barbara 2012). CUYAMA VALLEY REGION GROUNDWATER BASIN Cuyama The Cuyama Groundwater Basin underlies the Cuyama Valley, a rural agricultural area about 35 miles north of the City of Santa Barbara and is bound by the Sierra Madre Mountains on the south and the Caliente Range on the north. The climate is similar to high desert climate due to the surrounding high mountain ranges with average rainfall ranging from about eight inches per year on the valley floor to 24 inches per year at the crest of the Sierra Madre Mountains (County of Santa Barbara 2012). The four formations in the Cuyama Basin, which can supply water, are the Morales Formation, the Cuyama Formation, older and younger alluvium, and terrace deposits. The Paso Robles Formation also is found in the basin but yields no water because of its limited thickness and location above the water table. The basement rocks are basically comprised of marine sediments which are non-water-bearing or contain water that is unsuitable for human uses. The Morales Formation is the main aquifer in the basin, and its permeability varies greatly both laterally and vertically. Most wells tap as many water bearing horizons as possible, especially in the central part of the basin, taking water from both the alluvium and the Morales Formation (County of Santa Barbara 2012). The basin supports an estimated 20,000 to 25,000 acres of irrigated agricultural land, primarily planted with carrots, but also supporting a variety of other crops on a smaller scale, including alfalfa, carrots, potatoes, corn, sugar beets, grains, deciduous orchards, citrus, and irrigated pasture. Groundwater makes up 100 percent of water supply for the

13 area, with agriculture accounting for over 95 percent of the water use within the valley (County of Santa Barbara 2012). The petroleum industry located within the basin also uses groundwater for oil recovery and processing/transportation. With the limited groundwater resources in this basin, groundwater extraction is currently occurring at double the rate of recharge to the basin, resulting in effects such as groundwater quality degradation and subsidence, which vary depending of the location and depth of the withdrawals. The Cuyama Valley has generally poor groundwater quality, but has been able to effectively use these supplies to grow crops. However, the leaching of soils carries dissolved salts from the root zone to the water table and may impact water quality over time (County of Santa Barbara 2012). c. Storm Water The County encompasses approximately 2,735 square miles primarily consisting of rugged mountain terrain which can result in rapid local and regional watershed flow during major rain events. In the summer, the County s climate is generally warm and dry, while it is cool and wet in the winter months. The wet winter months normally range from October through April, with January and February typically bringing the largest amount of precipitation (County of Santa Barbara 2016d). Storm water runoff from lands modified by human activities can harm surface water resources and in turn, cause or contribute to an exceedance of water quality standards by changing natural hydrologic patterns, accelerating streamflows, destroying aquatic habitat, and elevating pollutant concentrations. Such runoff may contain or mobilize high levels of contaminants, such as sediment, suspended solids, nutrients (phosphorous and nitrogen), heavy metals and other toxic pollutants, pathogens, oxygen-demanding substances, and floatables. After a rain event, storm water runoff carries these pollutants into nearby streams, rivers, lakes, estuaries, and wetlands as well as the ocean. The highest concentrations of these contaminants often are contained in first flush discharges, which occur during the first major storm after an extended dry period. Individually and combined, these pollutants impair water quality, threatening designated beneficial uses and causing habitat alteration or destruction. Within rural and agricultural zoned lands, storm water can have the additional effect of increased sedimentation. When rainfall comes into contact with disturbed or tilled soil associated with agricultural land, it can be transported through the watershed at increased rates compared to vegetated land where soil is somewhat stabilized through a root system. The combination of loose soil and increased flow rates result in increased downstream sedimentation.. Storm water flow along creeks with natural banks may be susceptible to scour, bank collapse, or deeper incising of portions of the channel with increased runoff. d. Flood Hazard Areas As discussed in the Comprehensive Plan, although the severity and type of flood hazards can vary greatly based on variables such as topography, soil type, depth of the water table,

14 and microclimate, the County is subject to four major flood events: high flow rates in rivers, creeks, and other drainages; pooling and inundation; storm surge; and dam failure. Hazardous flood events commonly occur in proximity to rivers, creeks, and other smaller drainage corridors, with riverine flooding and flash flood events historically being the most damaging. Localized drainage problems can result from increased flow as well as ponding, which cause flash flooding, inundation, and other flooding problems. Streams are subject to high flows following periods of intense precipitation, and the floodwaters resulting from these high flows can impair the suitability of certain lands for various uses. Mapped flood hazard areas are defined by the 100-year floodplain. Flood hazard areas within the Project area are present along major rivers throughout the Project area (Figure 4.4-3). As detailed in the Seismic Safety and Safety Element of the Comprehensive Plan, the County has implemented a number of flood control projects to limit the negative impacts of flooding. The most prominent flood control project examples are the mechanisms used to limit flooding risks to the Santa Maria Valley. The amount of the peak floodwater in the Santa Maria River is first reduced by the storage of floodwaters in Twitchell Reservoir on the Cuyama River (the major tributary of the Santa Maria River). Secondly, levees have been constructed on the valley floor to contain the floodwaters originating below Twitchell Reservoir as well as the releases from that reservoir. The Santa Marie Levee, owned and maintained by the County Public Works Department, was built by the U.S. Army Corps of Engineers in 1963 to control flooding from the Santa Maria River, which endangered the City of Santa Maria. Based on the location of crop protection structures on 2015 aerial photography, approximately 193 acres of crop protection structures were identified within the 100-year flood hazard overlay and less than one acre was identified within a floodway within the South Coast/Gaviota Region Regulatory Framework a. Federal FLOODING Federal Emergency Management Agency The Federal Emergency Management Agency (FEMA) is the primary agency in charge of administering programs and coordinating with communities to establish effective floodplain management standards. FEMA is responsible for delineating areas of flood hazards. It is then the responsibility of states and local agencies to implement the means of carrying out FEMA requirements

15 Source: County of Santa Barbara, 2017 UV 166 a n t S a a M r i a UV 166 Guadalupe UV 1 Santa Maria i v e r R C u y a m r i v e a R C u y a m a R i v e r Cuyama Valley UV 166 P a c i f i c Ocean US 101 Santa Maria Valley i S s q u o c R i v e r UV 33 UV 1 UV 135 S t a n A n o n i o C r e e k Project Area Santa Barbara County Boundary Coastal Zone Floodway (County of Santa Barbara, 2017) Lompoc UV 246 UV 1 Lompoc Valley US 101 UV 154 Buellton Solvang Santa Ynez Valley UV 246 UV 154 S a n t a C r u z C r e e k o M n n o C r e e k o C r e e k 100-year Flood Plain (County of Santa Barbara, 2017) S S a n t a Y n e a n t a Y n e z R i z R i v e r e r Regions Cuyama Valley Lompoc Valley US 101 South Coast/Gaviota Santa Maria Valley Santa Ynez Valley South Coast/Gaviota 0 Miles 5[ UV 217 Santa Barbara UV 192 US 101 Carpinteria M:\JOBS5\8855\common_gis\Fig4.4-3.mxd 1/19/2018 fmm FIGURE County of Santa Barbara Flood Hazard Areas

16 The National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973 made the purchase of flood insurance mandatory for the protection of property located in Special Flood Hazard Areas. FEMA provides subsidized flood insurance to communities that comply with FEMA regulations. The Special Flood Hazard Areas and other risk premium zones applicable to each participating community are depicted on Flood Insurance Rate Maps. WATER QUALITY Water Pollution Prevention and Control Act (Clean Water Act) The Clean Water Act (CWA), enacted in 1972, is intended to restore and maintain the integrity of the nation s water, including lakes, rivers, aquifers, and coastal areas, through a system of water quality standards, discharge limitations, and permits. The fundamental purpose of the CWA is the protection of designated beneficial uses of water resources. Implementation of the CWA is the responsibility of the U.S. Environmental Protection Agency (U.S. EPA), which has delegated much of that authority to the U.S. Army Corps of Engineers, as well as state and regional agencies. Section 402/404 National Pollutant Discharge Elimination System Section 402 of the CWA established the National Pollutant Discharge Elimination System (NPDES) Regulations for municipal, industrial, and construction related pollutant discharges. U.S. EPA delegates Section 402 implementation to the SWRCB, as discussed further under SWRCB below. Facilities that discharge through a point source, including municipal and industrial sources, are regulated under the NPDES program and require permits for the discharge of pollutants. The NPDES permits specify discharge standards and monitoring and reporting requirements that a facility must achieve for each point source or outfall. The NPDES Municipal General Permit applies to certain designated urban areas, determined by census or as designated by the SWRCB. There are no NPDES-regulated urban areas within the Project area. Section 404 of the CWA generally requires permits for the discharge of dredged or fill materials into the waters of the United States, including wetlands. However, certain activities are exempt from permit requirements under Section 404(f). Section 404(f) exempts normal farming, ranching, and forestry operations that do not result in a point source from the requirement to obtain an NPDES permit. These activities may include plowing, cultivating, harvesting, and minor drainage for the production of food, fiber, and forest products or upland soil and water conservation practices. If an activity that is exempt represents a new use of the water, and the activity would result in a reduction in reach or impairment of flow or circulation of regulated waters, including wetlands, the activity is not exempt. Both conditions must be met in order for the activity to be considered non-exempt. Since the SWRCB is separate from and has different responsibilities than the California DWR, farmers subject to DWR supplies must apply for a waiver from the SWRCB or Regional Board through the Porter-Cologne Water Quality Control Act. The DWR protects,

17 conserves, develops, and manages much of California s water supply, including the State Water Project that provides water for 25 million residents, farms, and businesses. The Porter-Cologne Water Quality Control Act is discussed in detail below in Section b State and Region. Section 303(d)/Water Quality Standards The CWA gives states the primary responsibility for protecting and restoring surface water quality. Under the CWA, states that administer the CWA must review, make necessary changes, and submit the CWA Section 303(d) list to the U.S. EPA. CWA Section 305(b) requires each state to report biennially to the U.S. EPA regarding the condition of its surface water quality. The U.S. EPA requires both reports to be integrated. In California, the report is called the 303(d)/305(d) Integrated Report. Section 303(d) of the CWA defines water quality standards as consisting of both the uses of surface waters (beneficial uses) and the water quality criteria applied to protect those uses (water quality objectives). The Section 303(d) process of the CWA requires state and Regional Water Boards to assess water quality monitoring data for the state s surface waters every two years to determine if pollutant levels exceed water quality standards. Water bodies with pollutants levels that exceed water quality standards are placed on the state s 303(d) List. Exceeding the water quality standards on the 303(d) List initiates the establishment of a Total Maximum Daily Load (TMDL). A TMDL must account for all sources of the pollutants that caused the water to be listed. At a minimum, federal regulations require that the TMDL account for contributions from point sources and contributions from non-point sources. The U.S. EPA also reviews and approves the list of reported impaired waters and each TMDL. In some cases, a regulatory program will address the impairment instead of a TMDL. In California, the Porter-Cologne Water Quality Control Act (California Water Code Section et. seq.) requires that implementation be addressed when TMDLs are incorporated into Basin Plans (water quality control plans). The Porter-Cologne Act and Basin Plans are discussed in detail in the next following Section, b State and Region. The most recent U.S. EPA-approved Section 303(d) list of impaired waterbodies in California is the 2010 Integrated Report 303(d)/305(b), which assessed water quality data in California s waters to determine if they contain pollutants at levels that exceed protective water quality criteria and standards. Human activities and existing environmental conditions have the ability to affect the water quality of local surface waters and the ocean. The 303(d) listed waterbodies in the Project area are important to identify as impaired water bodies in order to receive a water quality control plan as a means to attain and maintain safe standards while allowing appropriate public health notification. Although development within the Project area is limited, water resources must receive state and federal regulations under the CWA and NPDES permitting process. The overall health and water quality of the streams in the Project area are important to maintain as they have the potential to pollute watersheds and water resources

18 b. State and Region PORTER COLOGNE WATER QUALITY CONTROL ACT The 1969 Porter Cologne Water Quality Control Act (Porter Cologne Act) established the principal California legal and regulatory framework for water quality control, including waste discharge requirements pursuant to the federal NPDES program. The Porter Cologne Act is embodied in Division 7 of the California Water Code, and established the SWRCB and nine Regional Water Quality Control Boards (RWQCBs) to coordinate and control the water quality within their respective jurisdictional boundaries. The Central Coast RWQCB is responsible for the water quality in County of Santa Barbara and oversees permitting for the region. The Porter Cologne Act also provides for the development and periodic review of Water Quality Control Plans (basin plans, described below) that designate beneficial uses of California s major rivers and groundwater basins and establish water quality objectives for those waters. Regional Water Quality Control Boards (Region 3 Central Coast). The state of California has established nine regions governed by RWQCBs. The RWQCBs implement and enforce provisions of the California Water Code and the CWA under the oversight of the SWRCB. The County is within the area regulated by the Central Coast RWQCB. The Central Coast RWQCB establishes region-specific requirements for point sources of waste discharge including discharges of municipal wastes, municipal storm water, individual industrial waste discharges, and solid waste disposal sites. These waste discharge requirements establish the minimum acceptable quality of the wastes, as measured by those water quality parameters that are of significance for each water body to which regulated wastes are discharged. The SWRCB, in cooperation with the regional boards, is charged with the responsibility for formulating overall water quality management programs. To accomplish this task, the SWRCB initiated the preparation of basin water quality management plans for each of the basins in the state. The Basin Plan for the Central Coastal Area was first adopted in April The current Basin Plan was adopted on September 27, 2017 (Central Coast RWQCB 2017). This Basin Plan is the Central Coast RWQCB master water quality control planning document. The Basin Plan sets the water quality standards and objectives for determining beneficial uses, impairment, and TMDL allocations for designated water bodies, and contains a recommended program for management of the quality of the water resources in the County, as well as encourages the use of reclaimed water. Localized Basin Plans allow each region to focus on the unique and particular needs of an area. As stated previously, water bodies and pollutants that exceed protective water quality standards are placed on the State and Regional 303(d) List. Exceeding the protective water quality standards on the 303(d) List initiates the development of a TMDL, and must account for all sources of the pollutants that caused the water to be listed. There are no TMDLs for the 303(d) list of impaired water bodies in the Project area

19 State of California law requires that anyone who is discharging waste that could impact the quality of waters of the state must submit a report of waste discharge. The State may waive discharge requirements if deemed in the public interest; however, waivers are conditional and may be revoked at any time. Prior to 1983, irrigated agricultural lands were operating under blanket waivers that did not require monitoring or reporting. Since then, regulations affecting irrigated agriculture discharges have continued to evolve and become more stringent. Irrigated Lands Regulatory Program To prevent agricultural discharges from impairing the waters that receive discharges, the Irrigated Lands Regulatory Program regulates discharges from irrigated agricultural lands. This is done by issuing waste discharge requirements (WDRs) or conditional waivers of WDRs (Orders) to growers. These Orders contain conditions requiring water quality monitoring of receiving waters and corrective actions when impairments are found. SWRCB Central Coast Region Order No. R Conditional Waiver of Waste Discharge Requirements for Discharges from Irrigated Lands (Ag Order 3.0) Ag Order 3.0 implements the States Irrigated Lands Regulatory Program. Ag Order 3.0 was approved on March 8, 2017 and regulates (1) discharges of waste from irrigated lands, including, but not limited to, land planted to row, vineyard, field and tree crops where water is applied for producing commercial crops; (2) discharges of waste from commercial nurseries, nursery stock production, and greenhouse operations with soil floors that do not have point-source type discharges and are not currently operating under individual waste discharge requirements; and (3) discharges of waste from lands that are planted to commercial crops that are not yet marketable, such as vineyards and tree crops (SWRCB 2017). Ag Order 3.0 requires individuals subject to the order (known as dischargers) to comply with the terms and conditions of the order to ensure discharges do not cause or contribute to the exceedance of water quality standards. Individuals subject to the order include both landowners and operators of irrigated lands on or from which there are discharges of waste that could affect the quality of any surface water or groundwater. Consistent with the Water Board s policy for implementation of and enforcement of the non-point source pollution control program, dischargers comply by implementing and improving management practices and complying with the other conditions, including monitoring and reporting requirements. Ag Order 3.0 requires the discharger to address impacts to water quality by evaluating the effectiveness of management practices (e.g., waste discharge treatment and control measures), and taking action to improve management practices to reduce discharges. If the discharger fails to address impacts to water quality by taking the actions required by this order, including evaluating the effectiveness of their management practices and improving as needed, the discharger may then be subject to progressive enforcement and possible monetary liability. Unlike the prior Agricultural Order, the current order includes conditions that allow for determining individual compliance with