Does the weir control the lake level?
The weir and downstream channel conditions in Pigeon Lake Creek help stabilize Pigeon Lake water levels for both wet and dry climate cycles. The level of the lake is primarily determined by the amount of precipitation received in any year. In sufficient amounts, the precipitation will offset the effects of evaporation and groundwater flow from the lake. When the lake level is below the spill point of the weir, in the absence of significant amounts of precipitation, the lake level will show significant rates of decline. When the level is above the spill point, the operation of the weir will only marginally reduce the rate of decline in level. This is because the flow rate over the weir is small in comparison to the evaporation rates.
Check out the following fact sheets for more information: