1 The lifetime costs of a reservoir and its water delivery system include construction and ongoing operation and management (such as intensive energy needs) for the reservoir itself, as well as for water treatment facilities and delivery pipelines and pumps. Eventually, reservoir infrastructure will wear out and will need to be replaced or repaired.
2 Revenue-generating farm, ranch and forest lands are often flooded and destroyed in the reservoir-creation process. When this land is privately owned and the family is uninterested in selling, the city or river authority may use eminent domain to take the land, regardless of whether the land is their source of livelihood or it has been in their family for generations.
3 When rivers are dammed to create reservoirs, wildlife communities are destroyed. This can necessitate costly wildlife management measures, such as the money currently being used to study threatened blue suckers in the Colorado River. And if already-threatened mussel species were to be further harmed because of reservoirs, water quality benefits could suffer because mussels naturally filter water and remove pollution. Expensive mitigation efforts likely would be required.
4 Reservoirs divert water from Texas rivers; without enough fresh water flowing through rivers into Texas bays to provide essential nutrients, sediments, and salinity moderation, fish and wildlife suffer, harming fishing and tourism-based economies.
5 Over time, sediment builds up in reservoirs, limiting their storage capacity and leading to diminishing returns. Reservoirs greatly increase evaporation rates, which also leads to diminishing returns.