Tuesday, April 04, 2006

Underground Water Storage

In this editorial from yesterday’s Bee, underwater storage of water is discussed; obviously a tactic that needs to be part of our over-all strategy of water storage and supply.

What also needs to be a tactic is surface water storage, or the water stored behind dams, as it is still the optimal storage, supply, and flood protection option for our region.

Here is an excerpt.

Editorial: The 'reservoir' below
Roseville looks to bank water underground
Published 2:15 am PDT Monday, April 3, 2006


Problems tend to create opportunities, and the Sacramento region's reliance on pumping groundwater is no exception.

Pumping from this supply, sometimes excessively, has created empty space in aquifers. Nature can slowly fill this space in years of abundant rain. Or water districts can more rapidly build up a supply by drilling wells and injecting water into them.

That is what the city of Roseville is doing in one of the first tests of its kind in Northern California. It is an important step in getting the public to think of groundwater basins as important new reservoirs.

Underground reservoirs are a little mysterious because the water isn't as visible as water stored behind a dam. In this Roseville experiment, the city has injected millions of gallons of American River water into this well. It has also drilled some monitoring wells nearby. That way, the city in the coming months can determine whether this stored supply is migrating somewhere in the groundwater basin or staying put. That information is necessary to operate any water bank.

In Roseville's case, the hope is to someday drill enough injection wells to store about 25,000 acre-feet of water (that is an acre of water a foot deep, or about 326,000 gallons) under the city. During extreme drought conditions, when river supplies are low or non-existent, this could be a key backup supply.

When Roseville is done growing, this underground back-up supply could be enough for six full months of regular deliveries (or even longer if conservation and drought measures are applied).