National Dam Inspection Program. Johnson's Pond (NDI-ID Number MD-11), Wicomico River Basin, Wicomico River, Wicomico County, Maryland. Phase I Inspection Report,
RUMMEL KELEPPER AND KAHL BALTIMORE MD
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The dam consists of a concrete and steel ogee spillway, wingwalls, and a clay fill embankment constructed on either side of the spillway. Including the lengths of clay fill embankments shown on the contract drawings of the dam, the total length of the dam is 580 feet. the Concrete and steel structure is comprised of a 300 foot long ogee spillway with wingwalls at the left and right abutments. According to the dam crest survey, the lowest point along the clay fill is elevation 14.5 and is located adjacent to the right wingwall. The crest elevation of the ogee spillway is 11.1, and a 30 foot long notch with a crest elevation of 10.6 is located in the middle of the spillway. Three sluice gates are located in the spillway directly below the notch. According to the hydrologic and hydraulic analyses, the Johnsons Pond embankment will overtop by 0.4 foot for a duration of 10 hours during a flood equaling 50 percent of the Probable Maximum Flood PMF. The analyses indicate that the Johnsons Pond spillway can pass approximately 43 of the PMF before overtopping commences.
- Civil Engineering