(a) “Groundwater Management Act” means Water Code Sections 10750 et seq.
(b) “Aquifer” means a geologic formation that stores, transmits and yields significant quantities of water to wells and springs.
(c) “Board” means the Board of Supervisors of Yolo County.
(d) “Commission” means the Planning Commission of the County of Yolo and the WRA meeting jointly.
(e) “County” means the County of Yolo.
(f) “Director” means the Director of Community Development or his designee.
(g) “District” means a district wholly or in part located within the boundaries of the county, which is a purveyor of waters for agricultural, domestic or municipal use.
(h) “Groundwater” means all water beneath the surface of the earth within the zone below the water table in which the soil is completely saturated with water, but does not include water which flows in known and definite channels.
(i) “Hydraulic gradient” means the slope of the water table.
(j) “Hydrology” means the origin, distribution, and circulation of water through precipitation, stream flow, infiltration, groundwater storage and evaporation.
(k) “Overdraft” means the condition of a groundwater supply in which the amount of water withdrawn by pumping exceeds the amount of water replenishing the supply over a period of time and also the point at which extractions from the supply exceed its safe yield plus any temporary surplus.
(l) “Percolation” means the movement of water through the soil to the groundwater table.
(m) “Permeability” means the capability of the soil or another geologic formation to transmit water.
(n) “Piezometric surface” means the surface to which the water in a confined aquifer will rise.
(o) “Porosity” means voids or open spaces in alluvium and rocks that can be filled with water.
(p) “Recharge” means flow to groundwater storage from precipitation, irrigation, infiltration from streams, spreading basins and other sources of water.
(q) “Safe yield” means the maximum quantity of water which can be withdrawn annual from a groundwater supply under a given set of conditions without causing overdraft or adverse water quality conditions. Specifically safe yields is the amount of water which can be withdrawn without:
(1) Exceeding in any calendar year the long-term mean annual water supply of the basin (considering all sources of recharge and withdrawal);
(2) Lowering water levels so as to make further drilling of water wells uneconomical;
(3) Causing water pumped from the basin to deteriorate below drinking water standards;
(4) Violating water rights or restrictions in pumpage in the groundwater basin as established by court adjudication or application State or Federal law;
(5) Other observable environmental damage.
(r) “Specific capacity” means the volume of water pumped from a well in gallons per minute per foot of drawdown.
(s) “Spreading water” means discharging native or imported water to a permeable area for the purpose of allowing it to percolate to the zone of saturation. Spreading, artificial recharge and replenishment all refer to operations used to place water in a groundwater table.
(t) “Transmissivity” means the rate of flow of water through an aquifer.
(u) “Usable storage capacity” means the quantity of groundwater of acceptable quality that can be economically withdrawn from storage.
(v) “Water table” means the surface or level where groundwater is encountered in a well in an unconfined aquifer.
(w) “Water year” means the year beginning March 1 and ending the last day of the following February.
(x) “WRA” means the Water Resources Association of Yolo County.
(y) “Zone of saturation” means the area below the water table in which the soil is completely saturated with groundwater. (§ 1, Ord. 1195, eff. December 26, 1996)