3/23/08 Logic by The Express Times
Time to revisit lowering reservoirs
Sunday, March 23, 2008
2008 Flood watch

Spring 2008. Right now we're in a fertile period for river-watching. And river-fearing, if you live along the banks of the Delaware River or one of its tributaries. What most people would like to know is whether we're about to add to the annals of recent disastrous floods: September 2004. April 2005. June 2006.

And if it is to be, could the next flood be offset by creating "voids" in the upper Delaware reservoirs? That question has set off a torrent of political and scientific conflict. More than 10,000 petitioners in favor of keeping the reservoirs at 80 percent capacity say "yes."

Various hydrologists say: It's not that simple. Some insist the reservoirs, by holding back water, help during floods. Then there are the vagaries of weather, which can switch from deluge to drought fairly quickly. The watershed is a big place; stream levels are affected by much more the three New York City-owned drinking-water reservoirs that get much of the attention as potential flood-busters.

All of this is a hard sell to those who've had to muck out after three devastating floods. A sense of urgency was reissued last week when the National Weather Service identified the Delaware Valley as a flood threat with a prediction of rainy spring weather. As of Friday, the three reservoirs were at or above 100 percent capacity, and spilling.

The good news is that the snowpack in the mountains is gone or barely there, according to a spokesman for the Delaware River Basin Commission. A repeat of 2005 seems unlikely.

So where is the case for better control of the river system today?

It's progressing. Last October the DRBC enacted a "flexible flow" plan approved by Pennsylvania, New Jersey, New York and Delaware and New York City, which aims to lower reservoir volume in wet periods and keep enough on hand for dry times. That's a step, but it's not enough.

A task force formed by the governors came up with a plan to mitigate flooding: redrawing flood plains, better stormwater control, limiting development, buying out property owners or helping them raise homes. It was an impressive list, but it's not enough.

The DRBC is readying a new set of watershed management rules. The Army Corps of Engineers is studying a model to see how reduced reservoir levels might have affected the 2004-06 floods. And the DRBC is preparing another study, to try to tie together all the data -- to address drought prevention, environmental protection, aquatic habitat, recreation, etc., along with flood control.

Clearly, we're in for an extended period of investigation and analysis, and because of the complexity of the watershed, this is a necessary process. Yet each spring, the Delaware presents itself as a laboratory to try out the "80 percent" experiment. It may all be a ruse, the idea that 20 percent less in the reservoirs would translate to anything more than a few inches of help at Portland, Belvidere, Easton, Carpentersville, Riegelsville. And a drastic reduction in reservoir levels could endanger the drinking water supply for 10 million people in the New York City area. No one's debating that.

Yet rather than wait for this to boil over into more lawsuits or expect Congress to fix a regional dispute, couldn't the four states and the city agree to try out some variation of the "void?" If the incoming data suggest that it's one piece of the puzzle, it's worth a try.