The lake discharges via a 200-foot wide concrete dam that is located at the northern tip of the lake.
The dam was built in the early 1920s and contains an 18-foot spillway with removable springboards allowing the lake levels to be seasonally managed.
A spillway height of 14 inches is maintained during the summer months. The lake water level has been raised and lowered seasonally to minimize damage from ice and to minimize encroachment of aquatic plants. The TLPOA has been managing this resource since the dam was constructed in the 1920s.
The dam is listed by the New York State Department of Environmental Conservation as a low hazard, class “A” dam and is built to handle the 100-year storm event.
[The above text was taken from the Land-Tech Report on Truesdale Lake, published September 5, 2001. It is available here.]
New York State Inventory of Dams
Name of Dam: Truesdale Lake Dam
State ID: 231-5160
Hazard Code: A
See below for hazard code definition
Year Completed: 1925
Most Recent Inspection: 6/19/2009
Municipality: Town of Lewisboro
River or Stream: TR-WACCABUC RIVER
Type of Construction: RE – Earth
Federal ID Number NY14813
Dam Length (feet) 200
Dam Height (feet) 14
Spillway Width (feet) 18
(cubic feet per second) 0
Maximum Storage (acre-feet) 720
Normal Storage (acre-feet) 400
Reservoir Surface Area (acres) 83
Drainage Area (square miles) 0
Basin LOWER HUDSON
Date of Data Update 1/24/2012
Last Condition Rating Not Rated