Copyright © City and County of San Luis Obispo 2019

September 11, 2019 GSC Meeting Summary

SGMA Compliance Efforts to Date

Attendees received a summary of SGMA compliance efforts to date, including background on governance, as well as the formation of the 
Groundwater Sustainability Agencies (GSAs) and the Groundwater Sustainability Commission (GSC). Compliance efforts completed since the June 12 GSC meeting include:

Chapters 1-2 Open for Public Comment

The consulting team of Water Systems Consulting (WSC) and GSI Water Solutions (GSI) presented a summary of Chapters 1 and 2 of the Groundwater Sustainability Plan (GSP), which covers materials for administrative information. A draft of Chapters 1 and 2 was approved by the GSC to be published to for public comment. Public comment for Chapters 1 and 2 remains open through 
October 31, 2019. To review the chapters and submit comments, please visit

  • Chapter 1: Introduction to the SLO Basin GSP — This chapter summarizes the purpose of the GSP, describes the characteristics of the SLO Basin, and explains why the Department of Water Resources (DWR) gave the Basin a high priority designation.

  • Chapter 2: Agency Information — This chapter summarizes the GSA governance structure, how the GSAs and the GSC are organized, the authority each agency has in developing and implementing the GSP, and the coordination agreement established between the agencies via the Memorandum of Agreement (MOA).

Basin Setting and Integrated Groundwater/Surface Water Model Update

The consulting team of WSC and GSI provided an update on the Basin Setting chapter, as well as the development of the integrated groundwater/surface water model. Drafts of Chapters 3-4 covering the Description of the Plan Area and Basin Setting will be presented at the December 11, 2019 GSC meeting; Chapter 5 covering the Groundwater Conditions will be presented at the March 11, 2020 GSC meeting.

The consultant team from GSI and Cleath-Harris Geologists presented a detailed description of the SLO Basin, including the following details:

  • Confirmation of the Basin boundary

  • Groundwater conditions within the Basin

  • The geologic make-up of the Basin and how it affects groundwater

  • Groundwater hydrographs and how they are interpreted

  • Gaps in the well monitoring network

GSI also gave a presentation about the integrated groundwater/surface water model. The model, which is being developed using GSFLOW, will simulate how water moves through the SLO Basin above- and below-ground. The model will be calibrated using past observed conditions to gain confidence that the water system in the SLO Basin is accurately represented and will then be used to simulate the effects of projects and management actions on the Basin.