Environmental Protection Secretary John Hanger announced this week Pennsylvania and other Delaware River states have negotiated an agreement with New York City that will reduce reservoir levels in the river basin to reduce the risk of flooding and benefit fisheries during the temporary shutdown of a major water supply tunnel that connects several of the city’s reservoirs.

The Rondout to West Branch Tunnel in the upper Delaware River Basin will close for a major repair project, and the city has agreed to divert as much as 50 billion gallons of water from reservoirs to the Delaware River between September 2009 and May 2010.

In addition to benefiting the freshwater fishery in the river and creating more reservoir storage capacity, the increased flows will allow Pennsylvania and other states in the basin to test a new weather and river forecasting tool that was recently developed by the National Weather Service.

The system will incorporate long-range weather forecasting and weekly monitoring to determine the amount of water to be released to maintain adequate reservoir levels and to provide sufficient flows to support aquatic life and recreational uses.

Releases from the city reservoirs will be higher when they are full and before wet weather arrives, further reducing reservoir levels below those established under previous agreements.

“This program is the result of an historic, cooperative effort on the part of New York City, Pennsylvania and other states in the Delaware River Basin to use excess water from the city’s reservoir system during the temporary shutdown of the Rondout to West Branch Tunnel,” Secretary Hanger said. “In addition, we will be using new scientific methods to assess real flow conditions so we can better manage water resources in the Delaware River basin to benefit fisheries, improve flood forecasting and protect water supplies.”

Pennsylvania and the other Delaware River states – Delaware, New Jersey and New York – signed the Flexible Flow Management Program with New York City in September 2007 that establishes a comprehensive, adaptive management program to better protect the basin’s water resources.

The increased flows during the water tunnel closing are temporary and will not have any affect on that agreement.

The Delaware River and its tributaries provide drinking water supplies for 15 million people. For more information, visit the Delaware River Master’s website.