Managing floodwater in big storms but saving enough for the dry season is a constant battle. But in the Turlock area, there might be an answer.
CERES, Calif. — It’s a constant battle in California when it comes to managing floodwater in big storms but also saving enough for the dry season. The recent cycle of storms brought both beneficial rain but hazardous conditions. It’s a classic example of large atmospheric rivers.
The benefits included bringing up the ground saturation, helping to fill rivers and lakes which had hit some historic lows, plus building up the snowpack which feeds the state with 1/3 of its water needs.
The statewide snowpack is just under 250% of average for the date. The more critical number though is the April 1 average which has reached over 100%. This date is important because it’s right around this time the snow stops falling and the snow melts, filling our downstream reservoirs.
Water managers have to keep enough capacity in those reservoirs to take in all the snowmelt. This becomes a delicate balance when storm cycles like what Northern California just had start delivering early season inflow.
Some water needs to be released to make sure there is enough capacity to hold all that snow.
The hazardous part of these atmospheric rivers results in too much rain and runoff in between weather systems. Roads, homes and communities are flooded. Water needs to be released from reservoirs and rivers can’t hold what is flowing.
Capturing all the extra water has been a key focus point of the state with groundwater taking front stage. This is the water beneath our feet that gets pumped to the surface in dry years. The Department of Water Resources says it can account for up to 60% of our water needs in some years.
Unfortunately, this retention area has been overlooked for years but is being given new consideration and resourceful ways to put water back underground.
The Turlock Irrigation District (TID) in the Central Valley is implementing a pilot program called “FloodMAR,” flood managed aquifer recharge.
They are currently working in three areas to use floodwaters that typically would be flushed out to the river system, through the Delta and then out into the ocean.
Wes Miller, a supervising engineer with TID, says their customers are predominantly or almost all family farms. They live in the area they farm so what they do on their ranches affects their homes. Finding ways to save this water protects their livelihood.
The way FloodMAR operates is to open up gates from canals, flooding the nearby land. This water then percolates underground to recharge the groundwater.
Miller says the water that fills these canals is from upstream reservoirs like Don Pedro and Hetch Hetchy. When water flows from those reservoirs it flows downstream by gravity, eventually making it’s way into a series of canals which carries water through the Central Valley.
When flows are high enough and the weather conditions are safe, they can then release some of this water into the nearby properties.
Miller says TID can’t necessarily claim a win for the water storage though because of complex existing water rights in the state. He says they are working through that, but ultimately, any water that they can put on land and not in the river is a good thing.
While it’s a lot of work and a lot of long days with these recent storms, Miller says there is a light at the end of the tunnel if they can prove this is helpful and will help others.