NYC helps upstate towns prepare for floods

The people of the mountain-ringed hamlet of Phoenicia, which is snuggled at the confluence of two world-renowned trout streams, were about to dig out the delta of silt dumped by two previous floods when Hurricane Irene hit at the end of August.

Tropical Storm Lee followed closely, turning Main Street into a roiling red river.

"Fortunately, we were able to take a prepared plan off the shelf and work in a way that otherwise would have been impossible," said Danny Davis, a hydrologist with the New York City Department of Environmental Protection.

The catastrophic flooding from Irene and Lee exposed planning gaps in small towns that are hard-pressed to pay for the engineering studies and sophisticated stream modification projects needed to reduce the devastation.

Here in New York's Catskill Mountains, a unique relationship with New York City brings top-level expertise and millions of dollars in construction cash to towns crisscrossed by flood-prone creeks.

Within a month, excavators had removed more than 20,000 cubic yards of sediment from a quarter-mile stretch of stream and bank -- enough to fill 86 boxcars.

Then, using hydraulic modeling that predicts the action of future floodwaters, engineers designed and installed a V-shaped boulder weir upstream from the Main Street bridge. The weir redirects currents to maintain a deep pool, prevent bank erosion, and keep sediments from creating a new sandbar.

"Basically, we re-engineered the stream channel to increase the flow," said Rob Stanley, town supervisor of Shandaken, which includes Phoenicia. "We hope not to have a repeat of the flooding we had in October and December 2010, and this past August during Irene and Lee." The town of Shandaken is one of those mountainous towns that have embraced a scientific approach to stream management. The work has started to pay off by protecting key roads from devastation and enabling an effective response to floods.

It's something other municipalities should be doing as well to prepare for more severe weather events brought about by global climate change, according to the New York State Energy Research and Development Authority. The agency released a 600-page "ClimAID" report in November as a resource for planners and policymakers.