Are drawdowns an effective way to control shoreline erosion, siltation, and aquatic plant growth?
Drawdowns are usually not useful in controlling shoreline erosion unless they are the only way to prevent significant springtime ice damage, which aggravates the process of soil loss by root damage and scouring. Ice damage can often be reduced by attaining a stable, slightly lower water level in the fall and actively managing the dam to keep at the target water level through the winter season and into the spring. This level should be chosen to avoid ice contact with unstable or sensitive shoreline but not so low as to cause problems with wildlife habitat or uses such as water intake pipes. Major level fluctuations can actually aggravate shoreline erosion in some areas if wave or ice action is concentrated below the level where cobbles and boulders have accumulated over the years. This is especially true for fairly steep shorelines where erosion below this cobble layer undercuts bank stability. Increased siltation along a lake shoreline is often a result of some new sediment supply, usu
