Groundwater recharge is the process where water moves downward from surface water to groundwater. Since there has been a decline in the Owens Valley groundwater supply, the need for recharge is a necessity. Mountain runoff, canals, ditches, irrigation, spill gate releases, precipitation and tributary systems are all possible sources for groundwater recharge in Owens Valley.
Recharge from precipitation is assumed to occur along the mountain fronts, but the exact quantity has yet to been documented. The California Water Science Center presented the assumption that about 95 percent of precipitation is evapotranspired, and the other 5 percent is recharged. Recharge also happens in multiple locations from the infiltration of excess irrigation waters to the spill gate releases along a tributary system. A tributary is a stream or river that flows into a main river or lake, and does not directly flow into a sea or ocean. Most tributary streams are measured at a gage station at the base of a mountain on land or by a stream and a river gages along the aqueduct.
There is a large degree of uncertainty in how to measure the exact recharge at the base of mountains, and this is what makes it even more important. It is assumed that an increase in recharge for one component with probably decrease the recharge levels for a different one. However, we do know that the principal source of replenishment in these areas are from the percolation of the stream flows that come down the mountains.
The map above is an extremely simple diagram showing the area I will be focusing on documenting the different sources of groundwater recharge and their amounts. In my research, I was able to identify all the sources of recharge for the area and was able to find very little useable recorded data on these multiple processes and their exact locations. Reports that are related to groundwater recharge and discharge are easy to locate, however the information on the quantity of water that actually infiltrates the permeable valley has become troublesome. I hope while sorting through this data, I can synthesize all these processes and quantities into an understandable visual language.