National Dam Inspection Program. Hawstone Dam, (NDI Number PA-C0580, Pennder Number 44-7) Susquehanna River Basin, Tributary to Juanita River, Mifflin County, Pennsylvania. Phase I Inspection Report.
Abstract
Based on a visual inspection, operational history, and available engineering data, the dam is considered to be in poor condition. Deficiencies noted by the inspection team include: (a) an overall lack of maintenance, (b) spalled and delaminated concrete surfaces along both faces of the dam, (c) leakage through the downstream dam face, (d) extensive cracking of the spillway structure and, (e) lack of drawdown capability. The size classification is considered to be significant. In accordance with the recommended guidelines, the range of the Spillway Design Flood (SDF) for the facility is the 100-year Flood to the 1/2 PMF (Probable Maximum Flood). Due to the potential for loss of life from sudden failure of the dam, the SDF is considered to be the 1/2 PMF. Results of the hydrologic and hydraulic analysis indicate the facility will pass and/or store about 39 percent of the PMF prior to dam overtopping. Thus, based on criteria contained in the recommended guidelines, the spillway is considered inadequate, but not seriously inadequate. The structure is considered stable in its percent configuration. However, because of the poor condition of the spillway, large discharges could possible cause undermining of the spillway structure and erosion at the toe of the dam which could result in structural failure. Thus, the facility is considered unsafe, non-emergency.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA082111
Entities
Organizations
- GAI Consultants, Inc.