Attractive and Beneficial: Groundwater Recharge Basins Can Be Both for People and Wildlife
February 26, 2021
With the lack of rain this fall and winter, comes anxiety about California’s water future for people, wildlife, and agriculture in California’s Central Valley. Our rainfall not only produces benefits at the surface like wildlife habitat and food crops, but it also recharges our stores of water below ground, otherwise known as groundwater aquifers. Even though we can’t see groundwater, and many of us don’t quite understand what it is, we all depend on it for the fresh water that we drink and use to grow our food. (More on what groundwater is here.)
California is facing one of the largest resource challenges ever: how to recharge or refill a depleted water table in the Central Valley, a hugely important region for wildlife and agriculture. The source of the problem is that more water is being pumped out of our groundwater aquifers, largely for the agricultural activities millions of people depend upon, than is able to be replenished by rain and melting snowpack each year. Inadequate groundwater stores are leading to irreversible ecological and economic crises like permanent loss of habitat and cropland and will get worse if we don’t act.
The challenge is great and so is the opportunity. On September 16, 2014, California Governor Jerry Brown signed into law the Sustainable Groundwater Management Act. The Act mandates that regions, overseen by locally-led Groundwater Sustainability Agencies, create and implement a plan that balances groundwater extraction and recharge by various methods between 2030 and 2035.
One of the ways we can add water to our underground aquifers is by building and managing recharge basins. These are natural or artificially constructed places that collect surface water, most often in the form of rain or snowmelt. The water in these basins eventually drains down through the soil and replenishes the groundwater level in the aquifer. But recharge basins can do more than just increase groundwater levels. If designed and managed with multiple benefits in mind, they can provide many additional advantages, such as habitat for waterbirds and other wildlife, as well as lessening flood risks and providing recreational benefits like a place to birdwatch, take walks in nature, and hunt to name a few.
Even now, before much of the new on-the-ground construction has begun, there are opportunities to modify some existing basins to create multiple-benefit, wildlife-friendly recharge basins. In a study by the Migratory Bird Conservation Partnership, led by Point Blue, we saw that as of 2018, 90% of existing recharge basins in California’s Central Valley were just bare soil or grass, which has limited value to wildlife. Given that loss and absence of suitable habitat is the leading cause of our biodiversity crisis, these recharge basins could be part of the solution.
With our partners at Environmental Defense Fund, Audubon California, and Sustainable Conservation, we created a guide for managers and farmers to make recharge basins wildlife friendly. Not only does the approach we provide support birds and other wildlife, it also helps to reduce sediment and clogging and stabilize the basins. The guide offers potential funding sources for these endeavors as well.
We recently partnered with Triangle T Ranch, a large ranch in the San Joaquin Valley, to evaluate their recharge basin and make recommendations that would help make it more wildlife-friendly. Triangle T only puts water on its basin in big water years and there was no guarantee they would flood the basin during the course of the study. But to our collective good fortune, California had a wet year during our study, and according to Kristin Sesser, Point Blue Avian Ecologist, “Even in a sea of orchards, if you put water on it, the birds will come. During our bird surveys after water was applied we saw waterfowl including those that breed locally like Mallards and Cinnamon Teal, as well as 11 species of shorebirds, including those on their migration north like Least Sandpipers, Dunlin, Long-billed Dowitchers, and even a Pectoral Sandpiper.”
At Point Blue, we see this as a ripe moment to bring a multiple benefit, collaboration-driven mindset to the planning table. We clearly see the ability to cultivate a more stable future for both farmers and wildlife in our great Central Valley. We know from experience that partnerships between conservation professionals, private farmers and ranchers, and government agencies work to bring benefits to all.
2020 marked the year that many of the Groundwater Sustainability Agencies’ draft water budgeting plans were due. Point Blue and our partners are excited and ready to influence revisions and implementation of practices as funding gets allocated in the coming years, especially when it comes to including and managing recharge basins. This is a long-term, critical, complicated task at hand. Most efforts in conservation are. And now we hope for more rain.