Aquifer recharge – storing surface water in aquifers for later use – may become a key strategy for managing increasingly scarce water resources during dry years. Communities in California and Arizona have been doing it for decades.
Aquifer recharge - storing water in aquifers for later use during dry years - has been used for decades in some communities in California and Arizona. Now, those states are expanding their use of the practice as other communities look into it.
Returning water back to aquifers can help ease water shortage concerns. In addition, higher groundwater levels can improve aquatic habitats by reconnecting streams and aquifers, which can help increase environmental flows that benefit plants and the animals that rely on streams. Increasing water mass in aquifers will also fill in pore spaces that, when left empty, can often compress and cause larger problems like land subsidence and sinkholes.
To those wondering why such a practice is necessary when, especially in California, so much rain has fallen recently, the problem comes from a lack of adequate capacity to store the massive amounts of water that fell over the last few weeks. In another few weeks, when the larger than usual snowpack starts to melt, if the reservoirs are full from rain, the meltwater has nowhere to go and flooding can be a concern. Aquifer recharge can alleviate some of these issues by storing water during the wetter years to make it available during the drier years.
Barriers to aquifer recharge include such issues as ensuring adequate quality of the water being stored for later use, especially if it will end up as drinking water. In addition, in some communities, that water has already been promised to downstream users, so aquifer recharge would take it out of service temporarily, leaving it unavailable to those with prior claims on the water.
In spite of the issues, more communities would benefit from the practice, since both drought and deluge seem to be the new normal, especially in the Western states.