Section 303(d) of the Clean Water Act establishes requirements for states and tribes to identify and prioritize water bodies that are water quality limited (i.e., water bodies that do not meet water quality standards). States and tribes must periodically publish a priority list of impaired waters, currently every two years. For waters identified on this list, states and tribes must develop water quality improvement plans known as total maximum daily loads (TMDLs) that establish allowable pollutant loads set at levels to achieve water quality standards.

The middle Snake River TMDL also covers portions of this subbasin.

The middle Snake River is a managed water system where normal flow regimes are no longer present, which allows sediment to accumulate. In general, the middle Snake River and its tributaries are impacted by runoff from irrigated crop production, rangeland, pastureland, animal holding areas, feedlots, dredging, hydro-modification, and urban runoff. Natural springs have exhibited hydro-modification and stream bank modification from activities relating to sedimentation, aquaculture, hydropower, irrigated crop production, and land development.

TMDLs were not written for ammonia, nitrogen, pesticides, oil and grease, or temperature. Data did not show that nitrogen, pesticides, or oil and grease were exceeding water quality standards or impacting beneficial uses. It will be recommended that pesticides and oil and grease be removed from the §303(d) list; nitrogen levels will continue to be reviewed by DEQ. Clover Creek was found to be polluted by ammonia, but ammonia is not listed on the §303(d) list for Clover Creek. It will be recommended that ammonia be added to the next §303(d) list for Clover Creek; a TMDL will be completed after this occurs. Temperature TMDLs have been deferred until after new water quality standards are developed for temperature (new standards are projected to be proposed in 2000).

This document is not available electronically. To view a hard copy, contact DEQ's Upper Snake Rock Watershed TMDL contact.

Draft wasteload allocations for aquaculture facilities were developed in July 2004. These allocations are designed to meet the total phosphorus reductions as specified in the Middle Snake River and Upper Snake Rock TMDLs. The allocations affect 37 TMDLs for total phosphorus and total suspended solids and six associated segments of the Snake River.

Public comments were accepted on the document in August 2004. In spring 2005, DEQ invited public comment on the document's aquaculture wasteload allocations separately in three parts. The aquaculture wasteload allocations were submitted to EPA for review in August 2005.

View Upper Snake Rock Watershed Management Plan – Modification - A Modification of Mid-Snake TMDL and Upper Snake Rock TMDL to Account for the Aquaculture Wasteload Allocation of Part 1 (Fish Production Facilities and Conservation Hatcheries), Part 2 (Fish Processors), and Part 3 (Billingsley Creek Facilities) (pdf 936 kb, 171 pages).