National Dam Inspection Program. Echo Lake Dam (NDI Number PA-00957, DER Number 48-3), Delaware River Basin, Tributary to Jacoby Creek, Northampton County, Pennsylvania. Phase I Inspection Report,
WOODWARD-CLYDE CONSULTANTS PLYMOUTH MEETING PA
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Echo Lake Dam and Reservoir are used for recreational purposes. The dam and spillway structure of Echo Lake are currently in fair condition and the outlet structure is in poor condition. The recommended spillway design flood for this Small size dam and Significant hazard potential classification is the 100 Year Flood to one-half of the Probable Maximum Flood. Based on the small capacity of the reservoir and the fact that no loss of life is likely during failure of the structure, the 100 Year Event has been selected as the spillway design flood. Hydrologic and hydraulic computations presented in Appendix D indicate the spillway structure is not capable of discharging the 100 Year Event while confining dam outflow to the designed spillway. With the spillway notch closed normal pool level, the right abutment area overtops by about 0.3 feet for an estimated five hours. Thus the spillway is considered Inadequate. If the spillway notch is permanently open, the spillway would be considered Adequate. Because of the potential for property damage in the event of failure, a formal procedure of observation and warning during periods of high precipitation should be developed and implemented for this facility. This procedure should be coordinated with local authorities and should include a method of warning downstream residents that high flows are expected. In addition, an operation and maintenance procedure should also be developed to insure that all pertinent items are carefully inspected on a regular basis and maintained in the best possible condition.
- Hydrology, Limnology and Potamology
- Civil Engineering