Regional Aquifer Recharge to Support San Pedro River Baseflows, Flood Flows and Groundwater

Transcription

1 Regional Aquifer Recharge to Support San Pedro River Baseflows, Flood Flows and Groundwater Brooke Bushman & Holly Richter, AZ Water Projects November 7, 2017

2 San Pedro River Tributary of the Colorado River Migratory corridor of hemispheric importance for 1-3 million birds annually First Riparian National Riparian Conservation Area designated in the U.S. Demonstration site for aquifer replenishment to sustain groundwater dependent ecosystem

3 Arizona s Future Water Security 3,000 + miles of perennial rivers At-risk basins in 2035 Results from Arizona s Water Resources Development Commission, 2011

4 San Pedro s Hydrologic Regime Groundwater, Perennial Baseflow, Natural Flood Flow

5 San Pedro Riparian Water Needs Groundwater and surfacewater accessible Perennial Reaches Intermittent Reaches Groundwater and surfacewater partially accessible Groundwater and surfacewater not accessible Ephemeral Reaches

6 Wet-Dry Mapping Long-term surfacewater monitoring Bella Vista Informs where managed aquifer recharge is needed the most Riverstone EOP Three Canyons Palominas Horseshoe Draw

7 A Regional Aquifer Recharge Network Cochise Conservation and Recharge Network (CCRN) Vision - A flowing San Pedro River, conservation of water resources, and a viable local economy. Members: Cities of Sierra Vista and Bisbee Cochise County Hereford Natural Resource Conservation District The Nature Conservancy

8 USGS Groundwater Flow Model Collaborative development of regional groundwater model that stakeholders trust Reports only baseflow, not total streamflow Grid size reasonable to provide project scale predictive results (250m x 250m, 15.4 ac) Used to optimize among and refine recharge locations to enhance baseflows in perennial and intermittent reaches

9 USGS Groundwater Capture Map From Leake and others, USGS years

10 CCRN Flood Flow and Urban Enhanced Runoff Modeling - UER Example of runoff hydrograph under pre-and post-development conditions in Bangalore, India (Adapted from Fig in Ramachandra and Mujumdar, 2009) /10

11 Aquifer Recharge Using Treated Effluent CITY OF SIERRA VISTA ENVIRONMENTAL OPERATIONS PARK 50 acres treatment wetlands 30 acres of rapid infiltration recharge basins Approximately 2,700 afy recharged By year-5 of operation, 5-mi diameter groundwater mound formed underlying river About 6 mi perennial reach enhanced by recharge

12 Aquifer Recharge Using Enhanced Sheetflow COCHISE COUNTY PALOMINAS FLOOD CONTROL AND RECHARGE FACILITY 20 acre basin collects sheet flooding from rural residential watershed Detention Basin Conveyed into constructed flood channel, divided into 13 recharge cells Each cell pilots different recharge technologies and assesses infiltration rates Constructed channel with 13 basins

13 Aquifer Recharge using Urban Enhanced Runoff COCHISE COUNTY COYOTE WASH RECHARGE FACILITY Located specific location for construction of a recharge facility with soil testing and groundwater modeling Surface water model estimates up to 630 AFA of urban enhanced runoff (UER) flowing off of urban Sierra Vista hardscape in this tributary NRCS funds in hand to move to shovel ready phase

14 Groundwater modeling scenarios

15 Modeling Input: Source water

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17 Temporal Baseflow Change At One Location 1,153 AFA (+82%)

18 Spatial Baseflow Change

19 Spatial Groundwater Change

20 Summary- Supporting a complex ecological system Manage for benefits to multiple dimensions of HYDROLOGIC FUNCTION using best available SCIENCE: Predict increased SPRNCA riparian area GROUNDWATER LEVELS Predict increased simulated BASEFLOWS across three stream gauges Model protection of FLOOD FLOWS Manage for benefits for PEOPLE and NATURE Predicted 54% of recharge goes to aquifer storage Predicted 44% of recharge goes to riparian flows Solutions are EXPENSIVE TO IMPLEMENT Initial MODELING & MONITORING investment is critical DUE DILLENGENCE

21 QUESTIONS