Cochise Conservation and Recharge Network Recharge Simulations with Updated Sierra Vista Subwatershed Pumping

Transcription

1 Cochise Conservation and Recharge Network Recharge Simulations with Updated Sierra Vista Subwatershed Pumping Presented to Upper San Pedro PAC Sierra Vista, AZ September 13, 2017 By Laurel J. Lacher, PhD, RG Tucson, AZ

2 Two-part Presentation: 1. Update of pumping and recharge values in USGS groundwater model. 2. Simulation of CCRN recharge at hypothetical full buildout.

3 Part 1: Pumping and Recharge Updates Actual pumping Municipal & Community Water Systems (as reported to ADWR). Domestic & other unmetered wells (estimated). Projected pumping Based on revised population projections from US Census/AZ OEO. Incidental (unintentional) and managed aquifer recharge (MAR). No changes in Mexico.

4 USGS MODEL AREA Sierra Vista Subwatershed

5 Incorporates Changes in Water Use Over Time 2005 Cessation of AG Pumping (3 Canyons)

6 New Greenbush Draw Recharge Added to Model Increased sales to FMI

7 Existing MAR in SVS: Sierra Vista s Environmental Operations Park (EOP) ~ 2700 AFA Bisbee s San José WWTF/Greenbush Draw AFA Tombstone s WWTP ~90 AFA Palominas Recharge Project ~ 40 AFA Horseshoe Draw Recharge ~ 40 AFA (predicted) Fort Huachuca s WWTF AFA

8 Simulation Results Two Ways Water Budget Components (whole model) Pumping Aquifer Storage Depletion Stream Baseflow Riparian Evapotranspiration (ET) Baseflow at Three Locations Charleston Lewis Spring Palominas

9 Water Budget Components

10 Pumping minus incidental recharge Change in model pumping is a combination of: 1. Updated actual water use ( ). 2. Corrections to prior estimates for unmetered wells. 3. Revised population predictions.

11 More riparian water

12 ~+9%

13 Where does pumped water come from? 1. Water in subsurface sediments (aquifer storage) 2. Water that WOULD have gone to, or stayed in, the riparian system (baseflow and evapotranspiration (ET)) under natural conditions. >>> When aquifer storage can t satisfy pumping demand, the rest must come from: CAPTURE RIPARIAN SYSTEMS OR MANAGED AQUIFER RECHARGE

14 Simulated Riparian Water (Baseflow + ET) Annual Volume (AF) 14,000 12,000 10,000 8,000 6,000 4,000 Riparian Water CAPTURE 2, Baseflow + ET 2011 Model Baseflow + ET

15 Baseflow at Three Locations

16 Stream-flow Gaging Stations

17 Simulated Annual Baseflow - San Pedro River at Charleston Acre-feet per year Model Model Year

18

19 Simulated Annual Baseflow - San Pedro River at Palominas Acre-feet per year Model Model Year

20 Summary - Update to SVS Model Pumping Simulated SVS pumping was reduced by about 5,700 AFA from 2002 to % pumping by muni & residential users increased while % of pumping for agricultural irrigation decreased model update reduced projected NET pumping by about 16% (7,000 AFA) in 2100 (relative to 2011 model update). Corresponding increase in riparian water (baseflow + ET) = 930 AFA (9%) by Current MAR projects are not sufficient to prevent increased capture of riparian water over 21 st century.

21 Part 2: Cochise Conservation and Recharge Network (CCRN) Recharge Simulations

22 Three Simulations 1. With CCRN recharge at hypothetical full build-out 2. Without CCRN recharge 3. With CCRN recharge at full build-out and 2,000-AFA reduction in Mexico pumping from 2020 to 2100.

23 CCRN Recharge Sites Wet/Dry Mapping Bella Vista EOP* identifies wet vs dry stream conditions long-term results inform decisions about where MAR is needed most. Riverstone Palominas* * Signifies built project Horseshoe Draw*

24 Model Input

25 MODEL INPUT CCRN Recharge at Hypothetical Full Buildout Simulated Managed Aquifer Recharge ( ) Hypothetical Recharge Senario Site Recharge Rate (AF/yr) Year ON Year Off EOP Basins EOP Wetlands Bella Vista CCRN Recharge Riverstone Riverstone Palominas RP Horseshoe Draw Horseshoe Draw Total CCRN Recharge Total CCRN Recharge EOP Basins No CCRN Recharge EOP Wetlands Horseshoe Draw Palominas RP Total No CCRN Recharge Total No CCRN Recharge

26 Simulated Hypothetical CCRN Recharge by Site AFA Pal HD RS BV EOP Upstream of partially dry reaches 2045 Year

27 Simulated No-CCRN Recharge by Site AFA Pal 0 HD RS BV EOP Year

28 Simulated 2,000 Acre-foot Reduction in Mexico Pumping USA Mexico SPRNCA Model Layer 4 Boundary Model Layer 5 Boundary SPRNCA Mexico Wells With Reduced Pumping [a] Model Area Boundary [b]

29 Simulation Results Three Ways Baseflow at Three Locations Maps of Baseflow Change in SVS Maps of Groundwater-level Change Near San Pedro River

30 Baseflow at Three Locations

31 Stream-flow Gauging Stations

32 1,153 AFA (+82%)

33 36 AFA (+16%)

34 57 AFA (+ 23%)

35 Maps of Baseflow Change

36 Simulated Baseflow Change 2003 to 2025 (cfs) Bella Vista Bella Vista Bella Vista EOP Riverstone EOP Riverstone EOP Riverstone [a] No CCRN Recharge [b] CCRN Recharge [c] Reduced Mexico Pumping with CCRN Recharge United States Mexico Palominas Horseshoe Draw Palominas Horseshoe Draw Palominas Horseshoe Draw

37 Simulated Baseflow Change 2003 to 2025 (cfs) Bella Vista Bella Vista EOP Riverstone EOP Riverstone [a] No CCRN Recharge [b] CCRN Recharge United States Mexico Palominas Horseshoe Draw Palominas Horseshoe Draw

38 Simulated Baseflow Change 2003 to 2050 (cfs) Bella Vista Bella Vista EOP Riverstone EOP Riverstone [a] No CCRN Recharge [b] CCRN Recharge United States Mexico Palominas Horseshoe Draw Palominas Horseshoe Draw

39 Simulated Baseflow Change 2003 to 2075 (cfs) Bella Vista Bella Vista EOP Riverstone EOP Riverstone [a] No CCRN Recharge [b] CCRN Recharge United States Mexico Palominas Horseshoe Draw Palominas Horseshoe Draw

40 Riparian/Aquatic Flora Accesses SW & GW Charleston Area Baseflow Supports Aquatic and Other Riparian Flora and Fauna Riparian Vegetation Accesses GW No Riparian Vegetation Palominas Area Shallow Groundwater Critical to Maintaining Riparian Habitat in Absence of Streamflow Tombstone Area Restoring Shallow Groundwater Critical to Regaining Riparian Habitat

41 Maps of Groundwater-level Change Near River

42 Bella Vista EOP Bella Vista EOP Increase in Simulated Groundwater Level with CCRN Recharge (ft) Model Layer 1 Riverstone Riverstone [a] 2050 [b] riparian acres 3680 riparian acres Palominas Model Layer 1 Boundary Palominas Model Layer 1 Boundary Horseshoe Draw Horseshoe Draw

43 Summary CCRN Recharge (to 2075) Adding CCRN recharge results in significant benefits to the SPRNCA downstream of the projects. Number of acres of riparian area in SPRNCA with simulated groundwater-level increases of 0.5 feet or more: 2050: 1, : 3,680 Adding CCRN recharge increases simulated baseflows by: 82% at Charleston, 16% at Lewis Spring, 23% at Palominas by Reducing simulated Mexico pumping by 2,000 AFA has no significant impact on simulated baseflows from

44 Thank you!