|Abstract or Summary
- Oregon’s stream gaging network was last evaluated in 1970 by the U.S. Geological Survey. Water management and scientific-related needs have changed significantly since 1970, including the recognition of instream water rights and implications of climate change on water resources. The Oregon Water Resources Department (OWRD) has recently undertaken an evaluation of the state’s stream gaging network in order to meet OWRD current and future data needs.
The OWRD goals (or data needs) for the stream gaging network are broadly grouped into those associated with water management and those associated with scientific purposes. The water management goal for the gage network is to provide discharge data required for timely and effective distribution of water by the state, and to meet conjunctive use management needs. The scientific goals include providing discharge data for: 1) regional regression analysis; 2) defining hydrologic systems;
3) accurate forecasts; and 4) long term trend analysis.
The management component of the gaging evaluation is complete and is under internal peer review. A qualitative approach was used in the evaluation after quantitative methods proved difficult due to variability in regulatory settings across Oregon. Over 1,000 watersheds, storage facilities, diversions and stream reaches were examined in the management component of the gage network evaluation. The evaluation identified 225 locations needing stream gages to meet OWRD’s water management goal. Currently there are active gages at 155 of these locations, leaving 70 sites where new gages are needed for surface water management. Of these locations, 31 were designated as high priority sites due to their regulatory, environmental, and logistical setting. These locations were predominately located in the south central and south eastern part of the state.
The stream gaging network is currently meeting today’s conjunctive–use management needs. However, there are 26 identified sites that may need monitoring to meet future conjunctive–use needs, pending further study. Currently gages are in operation at 19 of these sites for other reasons.