South East Management Area
WATER BUDGET An average annual groundwater budget for the South East Management Area for the last 5 years is presented in Table 4-1. The simple water budget for the IRWD portion of the South East Management Area is based on measured groundwater production and the subsurface flow calculated by the numerical model for the OCWD Management Area (Basin 8-1 Alternative 2017). The development of individual components in the average annual groundwater budget are described in the following subsections. 4.1 BUDGET COMPONENTS For IRWD’s Lake Forest portion of the South East Management Area, the components of the groundwater budget are presented in Table 4-1 and described below. Groundwater Production includes an average from 2016-2021. As of 2018, the groundwater production is zero until the LF-2 well can be rehabilitated and placed back in service.
Table 5
Table 4-1: Average Annual Groundwater Budget
South East Management Area Groundwater Budget 2016-2021 (acre-feet)
Total (acre-feet)
Item
Recharge Total Inflow
2,900 2,900
Groundwater Production
90
Subsurface Outflow
2,810 2,900
Total Outflow
Change in Storage
0
4.1.1 Recharge
Recharge includes infiltration from ephemeral creeks, precipitation and return flow recharge from irrigation. It was estimated to equal the total outflow as summarized in Table 4-1.
4.1.2 Groundwater Production
Groundwater production was taken from measured records by IRWD as summarized in Table 4-1. In the base period 2016 to 2021, groundwater production was only conducted by IRWD’s Well LF -2. Groundwater production in this well ranged from 0 to 389 acre-ft/yr. from 2016 to 2021 with an average of approximately 90 acre-ft/yr.
BASIN 8-1 ALTERNATIVE 2022 UPDATE
4-18 4 -1 Appendix F - 221
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