Upper Grande Ronde River, Oregon
Background: Elevated Summer Water Temperatures
Riparian areas play a critical role in regulating the temperature of rivers and streams. Wide spread alteration and/or removal of riparian vegetation elevates summer water temperatures. This, in turn, affects the ability of many northwestern rivers to sustain a healthy coldwater ecosystem that includes annual salmon runs and resident salmonid populations. A maximum water temperature of 77 F is considered lethal to salmon, and adverse effects on spawning and juvenile growth can occur at lower temperatures.
The Oregon Department of Environmental Quality is currently developing a temperature total maximum daily load for the Upper Grande Ronde River because elevated water temperatures have impaired the river's ecosystem. Objectives set by the Oregon Department of Environmental Quality are as follows:
(2) define riparian resource conditions to meet the temperature targets,
(3) develop watershed assessment methods, and
(4) ensure the transferability of the methods developed.
Several activities are underway to meet these objectives. The Oregon Department of Environmental Quality has established a temperature monitoring network in the Upper Grande Ronde River, which has been collecting summer data since 1992. In addition to the Oregon Department of Environmental Quality temperature monitoring network, the Forest Service has funded a temperature monitoring project in the Upper Grande Ronde River through Oregon State University. Between the two monitoring projects, excellent coverage of the watershed has been obtained. In addition to the temperature monitoring efforts, meteorological and flow data have been collected. The data will be used, in conjunction with the data from the riparian characterization project, in temperature model simulation, calibration, and verification. The temperature model will help the Oregon Department of Environmental Quality establish target temperatures for specific reaches and define the resource conditions necessary to meet the targets.Riparian Zone Characterization Project
Many of the environmental changes that lead to temperature impairment are visible and measurable from the structure of the stream and its riparian zone. Riparian characterization involves documenting stream channel morphology and streamside vegetation patterns, including alteration by various land use practices. A variety of methods are involved, including aerial photointerpretation, mapping, field reconnaissance, and geographic information systems analysis. The first goal of the Riparian Zone Characterization Project was to gather and analyze data for use as input values to a temperature model. Temperature modeling is intended to quantify the relationship between stressor (removal of shade) and response (elevated water temperature) in the Upper Grande Ronde River watershed. The second goal was the creation of a riparian characterization geographic information systems database to support watershed management, risk assessment, and restoration planning. The geographic information systems database will be widely shared with the other state, federal, tribal, and private geographic information systems users working on the Upper Grande Ronde River. The data, measurements, and geographic information systems database are essential to both the temperature model and the temperature total maximum daily load.
Elevated temperatures in the Upper Grande Ronde River were monitored using a series of temperature recorders situated along the mainstem and several tributaries. These and other data were used to determine temperature loading along different stream segments. Other available data on factors influencing water temperature include soils, groundwater, and meteorology. The Riparian Characterization Project provided several of the modeling parameters necessary to run the basin-scale temperature model. Project objectives, methods, and products are summarized in Table 6-6.
Temperature Modeling Project
The Nonpoint Source Control Branch of EPA's Office of Water and the Office of Research and Development at the Environmental Research Laboratory in Athens, Georgia developed a temperature model for the Upper Grande Ronde River basin in cooperation with the state. The model associated several watershed parameters, including different riparian zone characteristics, with effects on water temperature. This watershed-scale continuous stream temperature modeling investigation can be used to predict the spatial and temporal stream temperature regimes under different riparian forest management scenarios and to identify priority locations for stream restoration.
Stream Bank Stabilization and Riparian Vegetation Projects
The first two activities allowed Oregon Department of Environmental Quality to identify a list of projects which would stabilize the stream banks and provide the shade necessary for lowering instream temperatures to acceptable levels. The following list of restoration and education projects are proposed for funding by the Oregon Watershed Health Program from 1994 to 1996:
- Riparian fencing (2.5 miles) on Beaver Creek;
- Riparian fencing and vegetation recovery on Burnt Coral Creek. Cost-share sought for 1994 implementation;
- Rehabilitation of Camp Carson mine;
- Water monitoring workshop;
- Seminar series on Watersheds: The Critical Link, sponsored by the Blue Mountain Natural Resource Institute. This series was televised via EDNET to over 22 locations throughout the northwest.
Issues of Cost
The Watershed Health program funds restoration projects on both private and federal lands. The funding comes from a state lottery whose proceeds are to be spent on economic development projects. To date, efforts have been primarily directed toward private landowners. The private landowners that apply for grants are not required to share costs, although they are required to show that the project is being maintained. Funding of projects on federal land requires a 50 percent cost-share. Currently, the Watershed Health Program staff in the Grande Ronde basin are working with the GR Model Watershed Program and the Northwest Power Planning Council to identify areas in which to do projects and to rank projects for funding.
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