PASO ROBLES GROUNDWATER BASIN: WATER SUPPLY FRAMEWORK, HISTORY, AND CURRENT CONDITIONS CCVT Sustainable Ag Expo November 18, 2013 Paul A. Sorensen, PG, CHg Principal Hydrogeologist Fugro Consultants, Inc. www.fugro.com
Paso Robles Groundwater Basin 800 square miles 500,000 acres 30M AF groundwater in storage Maximum basin depth 2500 Average depth of aquifer 500-800 Page 2
Basin Hydrogeology and Water Balance Components Fault Offset of Water Level Evaporation / Transpiration Municipal / Industrial Pumpage B B Bedrock Well Rainfall Infiltration Recharge Ponds Alluvial Well Rainfall Infiltration NO 3? Drawdown AG Pumpage Waste Water + AG Perc. Bedrock Inflow Surface Runoff Surface Runoff Bedrock Outflow Page 3
Basin Conditions Perennial Yield (1997 data) (the rate at which groundwater can be pumped from wells without decreasing water in storage) 97,700 AFY Basin Pumpage 96,800 AFY (2011) Agricultural Water Demand 67,000 AFY (70% of basin pumpage) Page 4
History of Groundwater Pumpage Paso Robles Basin 140 130 Groundwater Pumpage (thousands of of afy) afy) 120 110 100 90 80 70 60 50 40 30 20 Perennial Yield -- 97,700 afy Perennial Yield -- 97,700 afy 10 0 1981 1982 1983 1983 1985 1984 1987 1985 1986 1989 1987 1991 1988 1993 1989 1995 1990 1991 1997 1992 1999 1993 2001 1994 2003 1995 1996 2005 1997 1998 1999 2000 2007 2009 2011 Net Agricultural Net Ag Pumpage M&I M&I Total Pumpage Groundwater Total Groundwater Pumpage Pumpage Page 5
History of Groundwater Pumpage Atascadero Basin 24 22 24 Groundwater Pumpage (thousands of afy) 20 18 16 Groundwater Pumpage (thousands of afy) 14 12 10 8 6 4 2 0 22 20 18 16 14 12 10 8 6 4 2 0 1981 1981 1983 1983 1985 1985 1987 1987 1989 1989 1991 1991 1993 1995 1997 Perennial Yield -- 16,500 afy 1999 1999 Perennial Yield -- 16,500 afy 2001 2001 2003 2003 2005 2005 2007 2007 2009 2009 2011 2011 Net Agricultural Pumpage M&I Pumpage Total Groundwater Pumpage Net Agricultural Pumpage M&I Pumpage Total Groundwater Pumpage Page 6
Change in Groundwater Levels 1997 to 2010 Page 7
Important Recent Actions - 1 Resource Capacity Study, Water Supply in the Paso Robles Groundwater Basin (SLO County Planning, August 2010) Concluded that Basin was at or near perennial yield Recommended that Board of Supervisors declare the Basin to be in a Level of Severity III Declaration of Level of Severity III (Board of Supervisors, February 2011) Page 8
Level of Severity III Definition: Water Demand Equals Available Resource Estrella/Creston Area of Concern greatest and most consistent area of water level declines Estrella Subarea has 16% of basin area and 40% of basin pumping Page 9
LOS III - Decision Making Constraints County has limited regulatory authority land use and building Majority of basin outflows not measured only municipal pumping Change in groundwater levels based upon limited data Page 10
LOS III - Recommended Actions Avoid Net Increase in Water Use Maximize Water Conservation County-Wide before new water considered Require Water Supply Assessments for new subdivisions by urban water supplier Improved Groundwater Data Collection Page 11
Groundwater Surface Elevation Spring 2013 Page 12
Water Level Trend Estrella Subarea Page 13
Water Level Trend Creston Subarea Page 14
Water Level Trend Atascadero Basin Page 15
Change in Groundwater Levels 1997 to 2013 Page 16
Water Level Declines Imbalance of Demand v. Supply Not a Drought Problem Page 17
Important Recent Actions - 2 Board of Supervisors, (May 2013) Directed staff to develop a team of experts to explore solutions, including Excess State Water (0 to 15,275 AFY) Salinas Dam (0 to 12,450 AFY) Excess Nacimiento Water Project allocation (0 to 6,095 AFY) Recycled Water (0 to 3,000 AFY) Directed staff to explore options for creating a jurisdictional water district or water agency with groundwater management responsibilities over the Basin Page 18
Important Recent Actions - 3 Blue Ribbon Steering Committee (August 2013) -- Solutions Ranking and Recommendations: Create a Basin-wide groundwater management structure Install water meters on all wells Require new development to be water neutral Require disclosure for land transactions Exchange/bank Nacimiento water with Santa Margarita Lake Deliver unsubscribed Nacimiento/SWP allocation directly to area of concern (in lieu) Page 19
Important Recent Actions - 4 Board of Supervisors (August 27, 2013) Passed Urgency Ordinance Applies to all unincorporated areas overlying the Paso Robles Basin Excludes: City of Paso Robles Atascadero Basin San Miguel CSD service area Shandon CSA service area Page 20
Important Recent Actions 4 (cont.) Board of Supervisors (August 27, 2013) Urgency Ordinance: Moratorium on new or expanded crop production, conversion of dry farm or grazing land to new or expanded irrigated crop production and new development dependent on a well unless such uses offset water use by a 1:1 ratio Certain exemptions (such as to drill a replacement well) Install meters on new wells (including replacement wells) Does not include a moratorium on new ponds and reservoirs In October 2013 extended Urgency Ordinance for two years Page 21
Availability of Supplemental Water Nacimiento Water Total SLO County Nacimiento supply 17,500 AFY Lakeside deliveries and supply 1,750 AFY SLO County water project supply 15,750 AFY City of Paso Robles 4,000 AFY City of San Luis Obispo 3,380 AFY Atascadero Mutual Water Company 2,000 AFY Templeton Community Services District 250 AFY CSA 10A (Cayucos) 25 AFY Total Commitment 9,655 AFY Available (uncommitted) 6,095 AFY Page 22
Solutions Never a water shortage, only a shortage of cheap water Reclaimed/Recycled water Conservation Water transfers Unallocated State Water Salinas Dam Retire undeveloped properties Import new water Desalination Page 23
Rural Domestic Community Initiatives PRO Water Equity Paso Robles groundwater basin Overliers for Water Equity Coalition of users, primarily rural residential Wants to develop a volunteer means of sharing the resource Solution based on demand management Page 24
Ag Community Initiatives PRAAGS Paso Robles Agricultural Alliance for Groundwater Solutions Promoting and developing a California Water District Landowner based (voting rights based on acreage) Solutions based on supply Page 25
Alternatives to No Action No Action has an inevitable consequence Adjudication Page 26
Thank You www.slocountywater.org www.ourwaterbasin.org www.prowaterequity.org www.praags.org psorensen@fugro.com www.fugro.com
Important Recent Actions 5 (cont.) Board of Supervisors (August 27, 2013) Formation of Management Structure Return in 45 days with options and recommendations for groundwater management structure RFP for expert consultant team Salinas River corridor State Water Project Use groundwater model to simulate impacts on basin from supplemental/imported water supply options Page 28