ARS | Publication request: IRRIGATION TAILWATER REUSE IN SOUTHERN IDAHO

Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: September 15, 1994
Publication Date: N/A

Interpretive Summary: In southern Idaho, water has generally been plentiful and inexpensive so tailwater reuse provided little direct benefit to the farmer and is not generally used. Because of water quality problems in the Snake River that is partially attributable to sediment and nutrients in surface irrigation return flows, there is a real possibility that farmers may be forced to dramatically reduce tailwater runoff from the farm. Tailwater collection and reuse is one way to accomplish this and will often be less expensive than converting surface-irrigated fields to sprinklers. A well-designed tailwater reuse system can add much-needed water supply flexibility to a farm irrigation system. System costs vary from $8,000 to $15,000 for a typical 30 Ha block of fields. On canal systems where some of the irrigation tailwater reenters the irrigation delivery network and is reused downstream, extensive on-farm reuse will require reallocation of water to farmers to account for the reduced return flows. Although tailwater reuse may be motivated by river quality concerns, farmers also gain significant benefits in improved water supply, reduced maintenance and improved long-term soil productivity.

Technical Abstract: Water quality deterioration in the Snake River may force farmers in southern Idaho to eliminate irrigation runoff from their farms. Tailwater reuse systems can accomplish this. Farmers and irrigation companies will also benefit from reuse systems. Reuse systems should be integrated with the rest of the irrigation system to maximize water supply flexibility.