2022-11-07_PERMIT FILE - M2022001 (13)

Home Browse Search

SECTION 3 - GROUNDWATER RECHARGE EXISTING SOURCES OF GROUNDWATER RECHARGE The purpose of this task was to identify sources of groundwater recharge that may most directly impact groundwater levels beneath the Town. The locations of recharge ponds, irrigation ditches and irrigated lands located near the Town were inventoried, as shown in Figure 3.1. We reviewed the DWR database and water rights decrees to identify the proposed location of additional structures and future potential infiltration (recharge) facilities and recharge rates for all structures. A summary of existing and proposed groundwater recharge facilities is presented in Table 3.1, including recharge facility location, historical recharge amount and maximum recharge rate. Recharge operations at the GMS Hunt, PVIC Hunt, Hunt W and Hunt SW recharge facilities are located immediately up-gradient from the Town and are likely to have the greatest impact on groundwater conditions. However, the historical amount of recharge at these facilities has been relatively small (25.1 to 162.1 acre-foot per year [af/yr]), compared to calculated groundwater underflow and the estimated rates necessary for dewatering described in later sections of this report. Although it is desirable to minimize recharge operations at these sites,they are not the sole cause for shallow groundwater conditions at the Town. The Evans No. 2 Ditch is located southeast of Town and previous groundwater modeling simulations have indicated that up to 5,614 of/yr of seepage from this ditch is a substantial source of groundwater flow beneath the Town. Anecdotal reports from irrigators that use the Evans No. 2 Ditch indicate that modeled ditch seepage may be overstated. The Evans No. 2 Ditch directly up-gradient from the Town can be used for recharge operations, (see decree in Case No. 05CW331, Water Division 1). However, irrigators report that this up gradient reach is not currently used for recharge. 12