Slide 1

Why a new groundwater model? Developing a new model for sacramento valley Annual DWR Geology & Groundwater Meeting December 3, 2014 Linda D. Bond, P.G. Integrated Regional Water Management Regional Planning Branch Slide 2 Source:USGS IT IS IMPOSSIBLE TO USE A NATURAL RESOURCE WITHOUT IMPACTING IT Resources are finite Regional, long-term impacts of pumping often take decades to be detected Management will come early by choice or later out of necessity The best we can do is understand the impacts minimize the impacts we can manage the impacts we cant minimize 12/4/2014 Geology Matters2 Slide 3 OUTLINE OVERVIEW OF GROUNDWATER-SURFACE WATER INTERACTIONS WHY A NEW MODEL? KEY FEATURES OF THE NEW MODEL 312/4/2014 Geology Matters Slide 4 FACTORS CONTROLLING STREAM DEPLETION CAUSED BY GROUNDWATER PUMPING Hydraulic Connectivity Well Location Aquifer Parameters: Transmissivity and Storativity Streambed Conditions 2014 RPB Understanding GW SW Connection 4 Slide 5 HYDRAULIC CONNECTIVITY BETWEEN GROUNDWATER SYSTEM AND STREAMS AQUIFER AND STREAM DISCONNECTED AQUIFER AND STREAM CONNECTED SACRAMENTO VALLEY 52014 RPB Understanding GW SW Connection SAN JOAQUIN VALLEY Slide 6 WHY DOES GROUNDWATER PUMPING IMPACT STREAMFLOW? Barlow and Leake 2012 Circular 1376 62014 RPB Understanding GW SW Connection Slide 7 HYDRODYNAMICS OF GW-SW SYSTEMS Storage Depletion To Streamflow Depletion Barlow and Leake 2012 Circular 1376 72014 RPB Understanding GW SW Connection Slide 8 DELAYED IMPACT SEASONAL PUMPING 12/4/2014 Geology Matters8 Time Delay To Full Capture of Streamflow Extends Over Decades Bredehoeft and Kendy 2008 Slide 9 DELAYED IMPACT SINGLE EVENT 92014 RPB Understanding GW SW Connection