DEQ has been working with partners in the Upper Deschutes and Little Deschutes subbasins for over 10 years to assess water quality in rivers, streams and lakes. The data gathered as part of this process indicate that, at some locations and times, water is not healthy for fish and aquatic life. The main water quality issues of concern include high temperatures, low dissolved oxygen concentrations, high pH levels, excessive amounts of algae (chlorophyll a) and excessive amounts of fine-grained sediment and turbidity.
DEQ contracted some of the temperature modeling work to Watershed Sciences, Inc., with financial support from EPA. This contract work was done from 2007-2011. Watershed Sciences completed Temperature Modeling Reports for this work. It is likely this initial modeling work done by Watershed Sciences will be modified by DEQ during TMDL development. The existing models may be revised to incorporate more site-specific input gathered from local stakeholders during the advisory committee process.
During the period 2000-2012, DEQ informally met with different groups and individuals around the region, discussing the upcoming TMDLs. These groups have included Upper Deschutes Watershed Council, Local Advisory Committee for the Upper Deschutes Agriculture Water Quality Management Area Plan, Deschutes Water Alliance, Working Group for the Deschutes Basin Habitat Conservation Plan, Water and Soils staff with the Confederated Tribes of Warm Springs, and others.
Technical Advisory Committee
In March, 2012, DEQ convened the Upper Deschutes and Little Deschutes Technical Advisory Committee The committee met five times in 2012 and provided valuable local input to DEQ on our technical analyses. DEQ postponed additional committee meetings and work on the models for temperature, dissolved oxygen, pH and nutrients in response to litigation on Oregon's temperature standard and the resulting court-ordered schedule for temperature TMDL replacement in 15 basins. DEQ has continued to implement nutrient monitoring that will support TMDL development.