Stiles Reservoir Dam Rehabilitation

Leicester, MA

Stiles Reservoir Dam Rehabilitation

Leicester, MA
  • Subsurface investigations
  • Geophysical evaluation
  • Stability analysis
  • Hydrologic/hydraulic analysis
  • Topographic survey
  • Design of repairs, improvements, & remedial measures
  • Low-level outlet design
  • Construction documents
  • Environmental permitting
  • Construction-phase services

Since its construction circa 1865, the Stiles Reservoir Dam experienced many deficiencies, concerns, and modifications. Despite extensive repairs and buttressing of the dam after a partial failure following a 1955 Hurricane, the deficiencies remained unresolved. There were several more recent attempts to control the seepage. These efforts proved unsuccessful and resulted in the MA Department of Conservation and Recreation Office of Dam Safety ordering an 8-foot drawdown of the impoundment to maintain a safe operating level until “such time that adequate repairs are completed to restore the dam to a safe condition.

In 2015, the Stiles Lake Watershed District retained Pare Corporation to develop a rehabilitation program to bring the 150-year-old dam into compliance with current dam safety regulations. Repairs included vegetation removal, hydraulic capacity improvements to accommodate the ½ Probable Maximum Flood (PMF) spillway design flood, embankment regrading and drainage improvements, a seepage cutoff wall to provide a stable upstream slope, spillway improvements to address maintenance requirements, and wetland impact mitigation.

Pare completed the design of repairs, prepared construction and bid documents, and secured permits from the regulatory agencies. Pare provided continued engineering services with a resident engineer present throughout the construction.