There has been a lot of talk about water supply the last few years. The ongoing drought has created some unique and extraordinary conditions throughout the western US. California in particular is enduring some extremely dry conditions with limited to no snow pack in the Sierra Nevada Mountains this spring. These mountains supply about 1/3 of our state water supply in an average year.
What many people may not realize is that this snow pack also provides surface water flow that recharges our groundwater basins. Groundwater is an important source of supply for people living in the Laguna Creek watershed. Recharge of these groundwater basins is critical because the water agencies supplying water to our residents rely on this source for a significant portion of our supply. Over 30% of the water supply in the Sacramento River watershed is from groundwater. In drought years that percentage goes up because of the lack of surface water supply derived from our snow pack in the spring and summer months.
Equally important is what groundwater does to support local ecosystems. The Sacramento Hydrologic Region has some of the highest concentrations of groundwater dependent ecosystems in the state. The types of ecosystems occurring in our local watersheds include wetlands and stream or creek discharge areas where groundwater flows at the surface. Current studies suggest that baseflow, where groundwater flows into the river, has been lost along the lower Cosumnes River and Deer Creek, both significant streams in our watershed. As you may recall from past feature articles these ecosystem types support a wide variety of unique species of vegetation and wildlife.
Where extraction of groundwater continues or increases (with or without drought conditions) is a concern for preservation of these valuable ecosystems. If groundwater levels drop the connection of groundwater supporting wetlands or creek flows could be reduced or lost. Fortunately recent groundwater level measurements in our area indicate groundwater levels are relatively stable. However as the demand for groundwater increases, especially due to the drought, levels could change. More data is needed to evaluate the potential impacts to groundwater dependent ecosystems in our region. The Laguna Creek Watershed Council is keeping an eye on the data and looking for ways we can help preserve these valuable groundwater dependent ecosystems. If you have any ideas please let us know.