National Program for Inspection of Non-Federal Dams. Winnekeag Lake Dam (MA 00007), Merrimack River Basin, Ashburnham, Massachusetts. Phase I Inspection Report.
Abstract
Winnekeag Lake Dam is a 260-foot long dry-stone masonry and earth dam built prior to 1878. The dam has a maximum height of 21 feet and consists of a spillway and separate outlet structure. The downstream slope of the dam is a vertical dry-stone masonry wall. Generally the dam is in fair condition. The following deficiencies were observed at the site: bulging of downstream stone wall; seepage discharging from the stone culvert low-level outlet; seepage downstream of the toe of the dam; several sinkholes on the crest of the dam adjacent to the downstream stone wall; animal burrows on the crest of the dam; voids between the stones on the downstream wall; erosion of the crest adjacent to the spillway right training wall; riprap missing from the upstream face of the dam; cracked concrete at the upstream end of the spillway left training wall; and an accumulation of debris in the low level outlet culvert and spillway discharge channel. The test flood would overtop the dam by 0.4 feet. Hydraulic analyses indicate that the spillway (without stoplogs) can discharge 1530 cfs, or 83 percent of the test flood outflow before the dam is overtopped. With stoplogs (1.4 feet high) the spillway can discharge 1,150 cfs or 47 percent of the test flood outflow before the dam is overtopped.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1980
- Accession Number
- ADA145339
Entities
Organizations
- New England District, U.S. Army Corps of Engineers