Title
Consider receiving 2019 Groundwater Level Contour and Historical Seawater Intrusion Maps.
Report
RECOMMENDATION:
It is recommended that the Monterey County Water Resources Agency Board of Supervisors:
Receive the 2019 Groundwater Level Contour and Historical Sea Water Intrusion Maps
SUMMARY/DISCUSSION:
August Trough Groundwater Level Survey
Each summer, Monterey County Water Resources Agency (MCWRA) staff conducts an intensive groundwater level survey of the northern Salinas Valley. Groundwater levels (GWLs) are sampled at approximately 160 wells from Chualar to the coast, to obtain a "snapshot" survey of conditions within and beyond the Seawater Intrusion Front. This is done during a time of the year when aquifers are most stressed by pumping. One of the key purposes of the survey is to monitor and assess groundwater level gradients sloping inland from the coast, driving seawater intrusion, which are most pronounced when pumping is at its seasonal peak.
Fall Groundwater Level Survey
In the late fall, from mid-November to mid-December, the MCWRA samples GWLs in approximately 460 wells throughout the Salinas Valley. The timing of this survey allows us to capture conditions in the groundwater basin at a time when a relative lull in agricultural pumping causes groundwater level troughs to relax, prior to the influence of seasonal recharge in response to winter/spring precipitation. In this way, the annual Fall survey of groundwater levels is an assessment of the relative, year-to-year change in groundwater storage throughout the valley.
Historical Seawater Intrusion
Each summer, MCWRA staff samples approximately 120 agricultural, urban purveyor, and small diameter monitoring groundwater wells in the coastal area of the northern Salinas Valley. Water quality samples are collected from the agricultural and urban wells twice, once in June and again in August. The MCWRA's network of small diameter monitoring wells is sampled once in September. Sample...
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