Documents from the BMC & ISJ parties
Note: the current BMC is made up of the former ISJ parties
The County ordinance that includes the growth rate provisions for Los Osos.
Basin Plan Groundwater Program Annual Monitoring Reports (AMRs)
Research Library
Documents prepared by official and expert sources we cite or reference in our letters, appeals, and other documents.
Documents from the County of SLO
The 2016-2018 report prepared by County Planning staff for the BOS that provides analysis, recommendations, and reasons for designating Los Osos at a Level of Severity III (LOS III) (the highest level of severity) due to undependable water resources.
A plan for reducing or avoiding impacts to habitat and protected species that the Coastal Commission is requiring the County to complete prior to approval of the LOCP. We understand that the County has incorporated some or all of the HCP DEIR into the LOCP and/or LOCP FEIR in an attempt to satisfy Coastal Commission requirements.
Attachment #8 prepared by County Planning staff before the 8-13-20 Planning Commission meeting that estimates the amount of exempt housing (ADUs, affordable housing, commercial space to residential conversions) that will be constructed in the next 20 years Los Osos and the water and conservation potential available to accommodate it.
Chapter 7: Planning Area Standards
Attachment #5 prepared by County Planning staff before the 8-13-20 Planning Commission meeting containing Chapter 7.3 “Community-wide Standards,” which includes the LOCP’s Basin/water supply-related criteria for approval of development
6-23-20 email from County staff to LOSG
An email explaining the criteria for approval of “affordable housing,” which is exempt from the growth rate limits of the Growth Management Ordinance (GMO)
Title 19, Section 19.07.042 “Water Conservation Provisions” of the SLO County Code
A regulation requiring retrofit offsets for new development that uses water from several Basins including the Los Osos Groundwater Basin. Los Osos provisions begin at the bottom of Page 2.
Coastal Plan Policies (County of SLO Local Coastal Plan Policy Document) adopted by the BOS March 1, 1988 (revised 2007)
A plan certified by the Coastal Commission Feb. 25, 1988 (revised 2007) that provides the policies for land use within the Coastal Zone (including all of Los Osos) and makes up a portion of the SLO County Land Use Element of the General Plan.
County regulations certified by the Coastal Commission October 7, 1986, governing land use within the Coastal Zone including Los Osos. Adopted by BOS March 1, 1988 (revised 2019).
The annual reports prepared for the BMC by Cleath-Harris Geologists (GHC), which provide updates of Basin conditions. The AMRs provide the most recent water use, water quality, and water level data and compare it against targets, also providing an update of program implementation, recommended adaptive measures, and other information about the Basin and BMC efforts.
The plan that the parties to the Stipulated Judgment agreed to as the “physical solution” for addressing seawater intrusion and developing a sustainable Basin and water source for the community. Provides the goals, Basin history, mitigation strategy and proposed programs, funding options, and other information. Programs include the Monitoring Program, Water Use Efficiency Program (conservation), Water Reinvestment Program (recycled water use), and Infrastructure Programs A-D (relocation of wells, nitrate treatment, and interties between purveyor systems).
The agreement between the four parties now making up the BMC, which resolves the dispute that resulted in the Los Osos Basin being an adjudicated basin. The four parties include the County of SLO, Los Osos Community Services District (LOCSD), Golden State Water Company (GSWC), and S & T Mutual.
Technical Memoranda (TMs)
A TM that reports and analyzes the modeled reductions in sustainable yield of the Basin in response to reduced annual average rainfall, which finds that the yield is reduced by at least as much as the percentage of rainfall reduction.
A TM that evaluates the need for additional Infrastructure Program C expansion wells for the current population to achieve a sustainable Basin condition, which finds that only one of the three proposed wells is needed based on modeling and Chloride and Water Level Metric trends at the time (which later reversed).
A TM that evaluates nitrate contamination of the lower aquifer from the upper aquifer at production wells due to well-bore leakage, and the rate of seawater intrusion into Zone E at Well LA11. The TM finds that several lower aquifer wells will exceed the maximum contaminant level for nitrates and seawater intrusion is advancing into Zone E.
Peer Reviews
Memorandum re: “Final Peer Review of the Basin Plan for the Los Osos Groundwater Basin,” Gus Yates
Technical Memorandum re: “Peer Review of the Los Osos Basin Groundwater Model,” Peter Pyle, Stetson Engineers, Inc. (Exhibit “C” of Los Osos Groundwater Basin Update, May 4, 2010)
Documents from the Los Osos Community Services District (LOCSD)
A memorandum prepared for the LOCSD and included in the April 15, 2020, BMC agenda packet describing the results of a test hole drilled for the LOCSD for Expansion Well #2 near the Los Osos Middle School, which showed that Zone E did not exist at the site and Zone D did not have the capacity to support a production well.
A TM prepared for the LOCSD that reports and evaluates location options for Infrastructure Program C Expansion Well #2 and the potential added yield possible according to modeling with the well installed.
A TM prepared for the LOCSD and included in the June 17, 2020, BMC agenda packet that provides the modeled sustainable yield for programs implemented at the time plus Expansion Well #2, which indicates (based on the model without metric and monitoring support) that installation of Infrastructure Program D Expansion Wells #1 & #2 will enable 150 AFY of “marginal yield” for additional development.
Note: Cleath-Harris Geologists, Inc. (GHC) prepared all of the AMRs and TMS listed above. In two of our letters to the County and BMC, the LOSG challenges the findings of the 2018 Adaptive Management TM prepared for the BMC and the Program Update TM (2020) prepared for the LOCSD (e.g., see letters dated 12-11-20 to the County and 3-12-21 to the BMC).
Documents from the Department of Water Resources (DWR) relating to the Sustainable Groundwater Management Act (SGMA)
BMP Framework (DWR, Dec. 2016)
BMP 1 Monitoring Protocols, Standards, and Sites (DWR, Dec. 2016)
BMP 2Monitoring Networks and Identification of Data Gaps (DWR, Dec. 2016)
BMP 3 Hydrological Conceptual Model (DWR, Dec. 2016)
BMP 4 Water Budget (DWR, Dec. 2016)
BMP 5 Modeling (DWR, Dec. 2016)
BMP 6 Sustainable Management Criteria (Draft) (DWR, Nov. 2017)
Also see the DWR website for the SGMA regulations and requirements
Documents prepared for the LOSG
Analyzes and discusses the urgency and seriousness of seawater intrusion in the Basin, uncertainties in the Basin model, and ways to address both.
Can Los Osos Valley Groundwater Basin Provide a Sustainable Water Supply?
CSU Monterey Bay Watershed Institute/Central Coast Watershed Studies, Publication No. WI-2010-04.
(We refer to this in letters as the “CSUMB 2010 Report” or a variation.)
A report prepared by a CSU Monterey Bay graduate studies class in fall of 2009 that discusses, analyzes, and makes recommendations regarding the mitigation of seawater intrusion and other adverse impacts challenging Los Osos Basin sustainability (e.g., potential impacts from the wastewater project and climate change). Key recommendations include (1) use of sustainable options including conservation, reuse, and low impact development, etc., (2) factoring delayed Basin responses to adverse impacts such as droughts and management actions into planning (timescales from a few years to hundreds of years), (3) erring on the side of caution when implementing mitigation programs and estimating safe yields due to significant uncertainty and unknowns inherent in Los Osos Basin hydrologic conditions, (4) having well-designed contingency plans in place to address areas of greatest uncertainty.
Analyzes and discusses the most sustainable and cost-effective programs to mitigate seawater intrusion in the Basin
Documents provided to the LOSG
per California Public Records Act (CPRA) requests
Includes project descriptions, the Title 19 water offset credits required, and the status of County building applications filed between 2010 and August 2020
Includes priority ranking, project type, and parcel size--lists 218 requests as of 1-7-20.
Includes priority ranking, requested units, and parcel size—lists 130 requested units as of 1-7-20
Correspondence regarding building within the wastewater service area, application process, fees, and archeologically sensitive areas.
2018 Adaptive Mangement TM (CHG, February 28, 2019)
Analyzes and discusses the most sustainable and cost-effective programs to mitigate seawater intrusion in the Basin
Recomments that, at a minimum, the BMC consider resetting the Agricultural Groundwater Production estimate back to 800 AFY. The BMC used an unreasonably high irrigation efficiency number of 92%.Typically drip irrigation systems have efficiencies ranging between 60% and 90% while sprinkler irrigation systems tend to have low efficiencies ranging between 50% to 70%.
The purpose of this sea water intrusion assessment is to document the historical rate of advance of the sea water wedge and the transition zone, and to establish the current position of these elements within the main aquifer zones of the ground water basin.
A plan for reducing or avoiding impacts to habitat and protected species that the Coastal Commission is requiring the County to complete prior to approval of the LOCP. We understand that the County has incorporated some or all of the HCP DEIR into the LOCP and/or LOCP FEIR in an attempt to satisfy Coastal Commission requirements.
As part of adaptive management for 2019, Cleath-Harris Geologists (CHG) has performed a review of trends in nitrate concentrations at various Lower Aquifer wells, along with an evaluation of the potential for seawater intrusion at Lower Aquifer well LA11 (Zone E; Pasadena Drive). The purpose of these efforts is to provide the Los Osos Basin Management Committee (BMC) with information and recommendations for making adjustments to the Los Osos Basin Plan (LOBP)1, as appropriate. This memorandum presents the results of the adaptive management review.
Transcription of the Los Osos Basin Management Committee Regular Meeting, August 16, 2023 (PFOS section only)
Annual report required by LOWWP CDP Special Condition 5d
The purpose of this sea water intrusion assessment is to document the historical rate of advance of the sea water wedge and the transition zone, and to establish the current position of these elements within the main aquifer zones of the ground water basin.