Fact 1: Damming a river can cause a lake to form.

Fact 2: There is no spillway at Lake Tahoe Dam.

Given the two facts above, answer the question "what can affect the level of a lake" with the following options: 
- boat traffic
 - flooding
 - boat shipping
 - erosion
 - Pollution
 - salinity
 - over fishing
 - spillways


 

        spillways 