Mulching to rebuild the topsoil
Everyone with a roof and a yard can help reduce flooding downstream by utilizing rainwater rather than letting it run into the street or the neighbor's property.  Begin by keeping the leaves that fall on your yard.  The piedmont lost some 6 inches of topsoil during the agricultural era a century ago, leaving a legacy of impoverished soils and unabsorbent ground.  Lawns, particularly in new subdivisions with compacted soil, can behave like impervious surface during heavy rains.  Spreading leaves as mulch on portions of your yard, or piling them in a back corner, is one way of rebuilding topsoil and creating a spongy layer of humus that can absorb rainwater.  It's also a great way of reducing maintenance, and helps shallow-rooted species like dogwood survive droughts.  Mulch, particularly pine needles and the narrow leaves of willow oaks, can be as attractive as what frequently passes for lawn.  Most dramatically in the fall, when trees dump on us big time, it becomes clear that Durham is a city that wants to be a woods.  Sometimes it's better not to fight it, give the leaves a place to return to the soil, and enjoy your newfound free time.

Putting the water to good use
Another interesting line of inquiry is exploring where the water goes from your downspouts.  Down your driveway?  Into your foundation?  Better to direct it out into the yard, where it can do some good, particularly where yearly deposits of leaves have made the soil absorbent, or where a depression will allow the water to seep in over a day or two.  The more water allowed to infiltrate into the ground, the more will be available for trees and shrubs during droughts.  Some homeowners create miniature fishponds in their backyards, lined with plastic or simply by the underlying clay, that are sustained by water from the roof and can be home to water lillies, pickerel weed and other long-blooming plants, not to mention frogs and fish.

ECWA is also hoping to make rain barrels available for homeowners.  Stored rainwater is said to be better for plants than the chlorinated water from faucets.

Discouraging mosquitoes
These approaches to keeping water around deal with mosquitoes in two different ways.  One is to make sure the water can seep into the ground over a couple days, so that mosquito larvae can't survive long enough to become adults.  In miniature fish ponds, on the other hand, mosquitoes are controlled by maintaining a population of fish to eat the larvae, e.g. the native mosquito-eating fish (gambusia, a cousin of guppies) that are common in Ellerbe Creek, and attracting predatory insects like dragonflies with diverse native vegetation.

Also see Steve's write-up on Controlling Mosquitoes.

Good water management makes good neighbors
The same storm water problems that plague Ellerbe Creek as a whole often play out on a miniature scale between neighbors, when the runoff from one property wreaks havoc on whoever lives just downhill.  If every neighbor takes responsibility for the rainwater falling on his or her property, using the methods mentioned above, a lot of neighbor to neighbor tension can be avoided.

On a community level, the way we handle storm water, by channeling it straight into the creek rather than putting it to use, greatly increases destructive flooding, and has a devastating effect on aquatic life.  Changing the status quo requires that everyone--businesses, new developments, homeowners--utilize storm water rather than spurn it.