Abstract:
Reston Association maintains 4 lakes on 125 acres, all of which were once fed by gliding streams
that now become roaring torrents during any passing rain storm. Lake siltation has accelerated as impervious surfaces have multiplied in the community development process. Ironically,
Reston’s lakes, designed as scenic and recreational amenities, now serve in addition as giant detention ponds in an evolving system of storm water management. The management principle
is to hold in porous ponds and depressions a substantial portion of run-off, permitting percolation of the soil to occur over time. The withheld run-off eases the magnitude and velocity of stream flow fed by storm water, thus reducing erosion and its adverse consequences.
So Reston’s lakes help protect landowners downstream, mostly outside Reston, and RA picks up
the tab for dredging the silt. Sure, of course, dredging is necessary anyway to assure recreational safety for Restonians. While silting conditions vary from lake to lake, the standard interval between one dredging and the next has been seven years at an estimated cost currently of
$220,000. RA is studying what portion of that cost can be eliminated by rehabilitation of water
channels upstream.
