The Corps of Engineers has completed a $20.5 million project to repair seepage and other problems at Vermont’s 5.52-MW Waterbury Dam.
The state of Vermont authorized refilling the project reservoir in September 2006 on the Little River, upstream from its confluence with the Winooski River. The Corps said it would monitor the 187-foot-tall dam for 18 months to ensure seepage control features operate satisfactorily.
In 1999, Vermont approached the Corps for help to address seepage at the 1,850-foot-long rolled earthen embankment dam. A 2004 federal appropriations bill directed the Corps to design and construct a repair for the dam’s concrete spillway and abutments supporting the tainter gates. The concrete was deteriorating due to an alkali aggregate reaction.
The state lowered the water level in 2000 due to dam safety concerns, and again in 2002 when the Corps began work. Hydro licensee Green Mountain Power Corp. operated the hydropower plant (No. 2090) at reduced capacity during the dam repair.
Alltech Engineering repaired the spillway. RAITO Inc. repaired seepage problems. Fleet Environmental restored and stabilized reservoir banks and planted vegetation to control erosion.
The Corps designed the dam as part of a regional flood protection plan for the Winooski River Basin. Construction was initiated in 1935; the Civilian Conservation Corps completed it in 1938. The dam was turned over to the state for operation and maintenance. Generation was added in 1953.