Research and Monitoring
Discharge and water quality monitoring (2002)
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RESEARCH AND MONITORING 2002-2005
Extensive monitoring conducted over the past 4 years demonstrates KBRT is delivering high quality water to the lake and water users below the valley. KBRT's research is independently reviewed by the USGS to assure scientific integrity.
* KBRT filed instream leases with the State of Oregon for 67,349 acre-feet of water. Prior to KBRT this water was spread over fields for flood irrigation, but now remains in the streams. There is increased stream flow due to landowners leaving their irrigation water rights in-stream. This is most notable in Sevenmile Creek, where a 2+ mile stretch of Sevenmile Creek ran dry from April 1 to October 1 for the past 50+ years, cutting off fish passage from the lake up to pristine forested habitat. A landowner signed a 5-year lease to leave his water right instream (and is hoping to make that lease permanent). As a result, the 2+ mile stretch that was once dry now has water flowing all year, and an Oregon Department of Fish and Wildlife fish survey on Sevenmile Creek in August of 2005 found the highest number and most fish diversity in this once-dry stretch of Sevenmile Creek.
Bowen Ratio station used to measure ET |
* The difference in crop water use (evapotranspiration) on irrigated and non-irrigated fields in the Wood River Valley is measured at 1.04 acft of water per acre of land. This means that using only ET as an estimation of water saved, then each acre of land that is no longer irrigated saves 1.04 acft of water over a season ... approximately 12,688 acft of water over the 12,200 acres in 2005.
* Research has shown that traditional flood-irrigation practices lead to increased nutrients and higher temperatures in the streams and lake. Monitoring results reveal improved water quality as a result of decreased runoff from flood irrigation and restricting cattle access to waterways.
* Groundwater monitoring demonstrates that the groundwater levels return to the same level each spring, recharged by winter precipitation. This allays fears that non-irrigation would result in a permanently reduced groundwater table, and confirms that each spring plentiful water is available for forage regrowth.
* Landowners have noticed a change in forage species, but not a decrease in forage. During the second year of non-irrigation some landowners were concerned about bare areas on higher ground where no vegetation was growing. However, in the third year these areas had almost all filled in with different forage species.
* Ranchers have noticed that grazing on lands with dry forage results in cattle gaining more weight (¡Ö30%) than on irrigated pastures. Cattle were also losing less weight during transport to other locations when winter arrived. Stocking rates were reduced to 25% - 40% of the rates when pastures were flood irrigated.
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