Los Osos Community Services District Basin Management Planning and Proposed Work Program June 5, 2008

Background  Los Osos Groundwater Basin Supplies Water to:  LOCSD  Golden State Water Company  S&T Mutual Water Company  Other Ag and Private Wells  Groundwater Recharge Comes from Many Sources Including:  Rainfall  Creeks  Irrigation return flow  Septic System Discharge  Leakage from Other Aquifer Zones

Background, Cont.  Safe Yield - the Amount of Well Pumping that Maintains Groundwater Levels Safely Above Sea Level, Even During Dry Periods  If Exceeded, Sea Water Becomes an Unlimited Source of Unwanted Recharge  Deeper Zones are More Prone to Intrusion  The Lower Aquifer Currently Supplies 77% of the Water Delivered by the Three Water Purveyors  Much of the Upper Aquifer is High in Nitrates, Blending or Treatment is Required

Area of Sea Water Intrusion into Lower Aquifer LOCSD Palisades Well

Sand Spit Downtown Creek Upper Aquifer (Zone C) Lower Aquifer (Zone D) Lower Aquifer (Zone E) Bedrock

Background, Cont.  Los Osos Groundwater Basin is Broken into Two Compartments  Urban Area – Comprised of the East and West Compartment  Creek Compartment

ISJ Agreement  September Water Purveyors and the County of SLO Entered into an ISJ Agreement  ISJ – Interlocutory Stipulated Judgment  Equitable Sharing of Costs Related to Data Gathering and Analysis, and Development and Implementation of the Basin Management Plan

ISJ Meetings  ISJ Group Members have been Meeting Monthly  A Mutually-Agreeable Work Program has been developed that:  Meets the Intentions of the ISJ  Maintains a Schedule that Facilitates Timely Input Into the County Wastewater Project

ISJ Meetings, Cont  County Applied for a $250,000 Department of Water Resources Grant  To Partially Fund ISJ Group Efforts  Application Did Not Receive Funding  Cooperative Efforts Between ISJ Group  Pursue Water Conservation Education Programs  Inter-ties Between Purveyor Distribution Systems

Undeveloped Property  In July, 2007, the County adopted a policy relating to wastewater assessments for vacant properties  A second wastewater assessment vote will be held for vacant and underdeveloped properties  Water supply and infrastructure projects necessary to serve development may be included  Funding from proceeds of the assessment vote can reimburse purveyors for costs relating to development

Work Program  Steps Required to Reach the Goal of the ISJ – Prepare a Basin Management Plan  Analyze the Existing Condition of the Groundwater Basin  Assess various methods for maximizing basin resources, including conservation  Evaluate the potential benefits of various wastewater disposal options

Work Program  Steps Required to Reach the Goal of the ISJ – Prepare a Basin Management Plan  Analyze the Existing Condition of the Groundwater Basin  Assess various methods for maximizing basin resources, including conservation  Evaluate the potential benefits of various wastewater disposal options

Work Program  Goals of the Work Program  Define improvements and related costs that are necessary to achieve a balanced basin under current demand  Explore opportunities for increasing the efficient, sustainable use of the basin with the County’s wastewater project  Define improvements and related costs necessary to achieve build out without importing water  Provide input to the County for wastewater project decisions and the future vacant property assessment vote

Work Program, Cont.  Proposed Program in Five Tasks (Tasks 1, 2, and 3, Staff is Requesting to Proceed with at this Time)  Task 1  Update Steady State Hydraulic Model  Adjust Build-out Projections of the Basin Water Demand, including water conservation  Preliminary Evaluation of Nitrate Removal Unit  Assess the potential of the upper aquifer before and after the wastewater project  Task 2  Evaluate and Determine Creek Compartment Safe Yield  Perform Sampling Analysis for Water Quality of Creek Compartment

Work Program, Cont.  Task 3  Prepare Groundwater Basin Infrastructure Master Plan  Evaluate Groundwater Recharge Opportunities  Evaluate Options for Beneficial Re-Use of Reclaimed Water  Prepare a Draft Basin Management Plan  Task 4  Prepare a Transient, Dual-Density Hydraulic Model of the Groundwater Basin  Task 5  Annual Groundwater Monitoring  Transient Model Updates Every Two Years

Funding  Funding Sources for These Tasks Depend on the Objective  Tasks 1 & 2 Address Existing Deficiencies Related to Current Development  Funded by the ISJ Group (Ultimately by Rate Payers)  Percentage of Total Costs Based ISJ Agreement  District Share – 39%

Funding, Cont.  Task 3 Benefits Future Development,  Task is Completed Prior to Assessment Vote  District to Fund Up Front Costs  Will be Reimbursed if Assessment Vote is Passed  Tasks 4 & 5 Benefit Future Development  Tasks to Commence Following Secured Funding Source

Work Program Costs  District Share (39% of Work Program)  Task 1$ 8,500  Task 2$ 7,500  Task 3$45,000  Contingency$10,000  Total$70,000

Schedule  June 2008 through August 2008 – Water Purveyors Approve Work Program and Authorize Consultants to Proceed with Tasks 1 & 2  August 2008 through February 2009 – Completion of Task 3  March 2009 – County’s 2 nd Proposition Vote

Recommendations  Board to Approve Funding of Purveyors Basin Management Planning and Proposed Work Program in Accordance with the ISJ Agreement

Questions