Draft 2025 Urban Water Management Plan

Rubber Dam (r 2 =0.99). This demonstrates that there are no net losses in flow between these two locations, at least within the margin of error in the measurement accuracy. The conclusion is that the flow measurements at the two gauges are consistent with the water level data that show that the Santa Ana Canyon Management Area is in hydrologic equilibrium, and also that the volume of groundwater pumping is relatively small so as to not measurably reduce surface water volumes through the canyon.

Comparison of Prado Outflow vs Imperial Dam Inflow (May-October, 2015-2021)

500

y = 1.02x R² = 0.9895

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0

0

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Prado Dam Outflow (cfs)

DWR has made a dataset, called “Natural Communities Commonly Associated with Groundwater (NCCAG) Dataset” available at NC Dataset Viewer (ca.gov). This dataset shows that there is riparian vegetation located in the Santa Ana Management Area along the SAR channel. The evapotranspiration associated with the riparian vegetation was estimated to be 740 afy as shown in Table 1-2.

La Habra GSA Response:

Requested information on whether surface water bodies in the La Habra-Brea Management Area are interconnected with groundwater and whether groundwater-dependent ecosystems exist within the La Habra Management Area is included in the 2022 Update.

Appendix F - 282

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