The goal is to restore the quality of the lower Yakima River water so that it meets state water quality standards. Our sampling indicates tens of thousands of tons of top soil are eroded from valley farms during the irrigation season. The soil is carried down the drains and ends up in the Yakima River. That's bad for agriculture and it's bad for the fishery that we're trying to restore in the river. The new report is called A Suspended Sediment and DDT Total Maximum Daily Load Evaluation Report for the Yakima River.
Particles can also settle and clog spawning gravel or suffocate fish eggs.
Muddy water makes it difficult for fish to migrate and find food. Ecology, Yakama Indian Nation and several other state, federal and local agencies now will be working together with area growers to identify the best and most cost-effective ways to reduce soil erosion and runoff from farms. Public comment and involvement is an essential ingredient in the success of this project. According to the report, most of the sediment is eroded from farmland by poor irrigation water management and is carried back to the river through the irrigation return drains. One of the early recommendations is for growers to convert to sprinkler and drip irrigation where appropriate to eliminate tail water runoff and the resulting top soil erosion.