D.C. Water said Thursday that it plans to prevent flooding in the Bloomingdale and LeDroit Park neighborhoods by embarking on a massive infrastructure project that will create 12 million gallons of stormwater storage.

The agency announced that it will use the McMillan sand filtration site as the location for 6 million gallons of storage that should be available by spring 2014.

D.C. Water will also begin digging a tunnel below First Street Northwest that will hold another 6 million gallons and will be completed in 2016.

The new strategy will shave as many as nine years off previous estimates of when the two neighborhoods would see extensive relief from the threat of torrential flooding.

The new construction is expected to add about $40 million in costs to a larger $600 million project.

Earlier this year, Bloomingdale and LeDroit Park flooded on multiple occasions, causing extensive damage and leading to the urgent efforts to develop a new strategy.