Such improvements can also be aesthetic in nature and help the local economy by supporting tourism. The reason is that the water is already flowing at or near the river's natural flow rate. These changes commonly result in lost capacity to generate power when it is in highest demand and most valuable. White Water Boating One of the factors in juvenile salmon mortality is the length of time it takes to migrate to the ocean. When this occurs, water not passing through a turbine area is released over a dam's spillway.
Water is stored and then released in concert with juveniles migrating downstream in the Spring.
Freshet refers to the turbidity and other water conditions that occur when water is flowing rapidly downstream as a result of conditions such as rainfall, snowmelt, or sudden release of water from a reservoir. From a recreational perspective, the timing and length of spills can dramatically affect conditions for white water rafting, kayaking, and similar activities. By doing so, a project loses all or most of its ability to store water and thus regulate the generation of electricity to times when it is most needed and valuable. How much to draw down reservoirs has been the subject of much debate. One issue is that while new rearing and spawning habitats for some species will emerge, habitat for other fish and wildlife will be lost.