National Dam Inspection Program. White Heron Dam (Minisink Lake), (NDS ID PA 00636 DER ID 45-116), Delaware River Basin, Marshall Falls Creek, Monroe County, Pennsylvania. Phase I Inspection Report.

White Heron Dam is a 34 foot high earthen embankment with an impervious puddled clay core and a wooden cutoff wall. The 1,450 foot long embankment impounds a 55 acre reservoir with a 614 acre-foot normal storage capacity. The upstream and downstream slopes are 2H1V from the toe to seven feet below the crest. Thereafter, the slope increases to 1.5H1V. The average measured crest width is 14 to 15 feet. The minimum width was measured as 10 feet and the minimum crest elevation is 709.8. The downstream slope is covered with grass and the upstream slope is protected with riprap from the crest to elevation 698 or -. There are no internal drainage systems incorporated in this embankment. Water is normally discharged through the concrete spillway located at the left abutment. The spillway weir is 20 feet long with a crest elevation of 706. The structure contains two pond drain pipes with gates at the upstream toe. The gate stems extend from the reservoir bottom to just below normal pool level. Water discharges through the two parallel 12-inch cast iron pipes into a small minnow pond at the downstream toe.