What is the maximum pool elevation, inflow, or outflow ever reached at one of the Philadelphia District Flood Control Dams?

Statistics on each project may be found on our historical data page.

What is "NGVD"?

NGVD stands for National Geodetic Vertical Datum.  It is a datum for measuring elevations and corresponds approximately to sea level.  NGVD has been superseded by NAVD (North American Vertical Datum), however the difference in datums is less than one foot.

Is it possible to release colder water from the "bottom" of F.E. Walter Dam?

Although most of the dam's releases are made from large flood control gates located on the reservoir's bottom, smaller releases can also be made from bypass gates located about 50 feet above the reservoir's bottom.

How does the Army Corps of Engineers determine how much water to release from F.E. Walter Dam?

Many factors are considered each day, sometimes each hour, to insure the successful operation of F. E. Walter Dam. Typically, the outflow is set to match the inflow in order to maintain the normal pool elevation of 1300 feet NGVD.   At approximately 1309 feet the road and the boat launch area on the upstream side of the dam are flooded. Except for the summer when the pool is raised to 1370 for recreation, to preserve in-lake recreation, keep the road open, and maintain flood water storage capacity, lake levels are usually kept below 1309. When a large storm threatens the area, Walter Dam is called upon to perform its primary mission of providing flood control protection. During a large storm, the dam holds back water until after the storm has passed and it can be released safely. Sometimes another storm is forecasted and this water has to be released quickly. Walter Dam has been quite effective in fulfilling its primary mission of reducing flood damages in the Lehigh River. There are other factors which also affect release decisions. A plan to enhance recreation was developed for the 2005 season and has been evolving ever since. You may learn more about the plan here. Scheduled whitewater releases are generally in the 500 - 750 cfs range. At other times, releases may be influenced by other needs such as fish stocking, search and rescues, construction, clean-ups, or drought mitigation.

What are the current releases from Philadelphia District Flood Control Dams?

Current reservoir releases and streamflow data may be found on our realtime data page.

When is the next whitewater release from F.E. Walter Dam?

Check the whitewater release schedule.

What is "cfs"?

Answer : A measurement of water flow equivalent to one cubic foot of water passing a given point for an entire second.  One cubic foot per second  is approximately equal to 7.5 gallons per second or 646,000 gallons per day.