The Presa de Tous has a sad history, on October 20th 1982 the dam burst, there were 9 fatalities, and thousands left homeless. The dam was rebuilt in 1991
When looking at the map it appears you can access the lake from Tous on the east, and Sumacarcer from the south, this is not the case. You can not access the lake from Sumacarcer, the road is closed to traffic.
Although, there is an interesting body of water below the dam.
Fishing In Spain
Exploring The Waterways
In La Comunidad Valenciana