La Habra-Brea Management Area
SECTION 9. MANAGING GROUNDWATER LEVELS A solid understanding of groundwater elevations, seasonal fluctuations and response to pumping, existing basin yield, and how groundwater is stored and transmitted through the basin is critical for sustainably managing the La Habra-Brea Management Area. 9.1 HISTORY OF BASIN CONDITIONS AND MANAGEMENT ACTIONS As shown on Figures 3-4, 3-5, and 3-6, groundwater levels in the La Habra-Brea Management Area have recovered from lows in the 1930 to 1950s and have experienced a general rising trend and leveling off since the 1970s. Given consistent groundwater production within the estimated safe yield of the basin, groundwater levels are expected to remain steady in the future.
9.2 MONITORING OF GROUNDWATER LEVELS
The City of La Habra recognizes the great importance of monitoring groundwater levels and acknowledges the current data gaps in the monitoring network. Monitoring groundwater levels is critical to basin management because water levels impact other potential undesirable results: loss of groundwater in storage, degraded water quality, land subsidence, and depletion of interconnected surface water. Groundwater levels can serve as a proxy for identifying potential impacts related to other groundwater conditions. As discussed in Section 5.2, the City has measured non-pumping and pumping groundwater elevations at its production wells since 2008. At the time the Alternative was first being developed, there were several additional wells actively being monitored in the La Habra Basin by other agencies. These wells with water level data included wells 3/10-9G1, 3/10-8B2, and 3/10-18C1. Many of these wells are no longer being monitored which is causing data gaps. Accordingly, La Habra is currently evaluating potential groundwater wells for inclusion into an expanded monitoring program as part of compliance under SGMA. The need for standard and multi-level monitoring wells to monitor the three aquifers of the basin is being investigated. The La Habra GSA may potentially request State assistance through the Technical Services Support program to install additional monitoring wells. The proposed monitoring program will include wells located within the vicinity of the La Habra Basin. La Habra has been in coordination with the Department of Water Resources regarding wells located in the La Habra Basin that have previously been included in bulletins/reports published by the Department of Water Resources (DWR) in order to acquire pertinent well information that is not publicly available. These wells and other existing monitoring wells are currently being screened and evaluated for available data and suitability for inclusion in the monitoring network for the La Habra Groundwater Basin. Updates and modifications to the monitoring network will be discussed in the next Annual Report.
2017 BASIN 8-1 ALTERNATIVE
9-2
Appendix F - 42
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