Presentation on theme: "David P. Statler n Nez Perce Tribe n Department of Fisheries Resources Management n Director of Resident Fisheries."— Presentation transcript:
David P. Statler n Nez Perce Tribe n Department of Fisheries Resources Management n Director of Resident Fisheries
Dworshak Integrated Rule Curves/ Monitoring and Evaluation Proposal 198740700
Dworshak Dam and Reservoir are located in the Clearwater Subbasin of the Mountain Snake Ecological Province, about - 35 miles east of Lewiston, Idaho. Regional Location
Subbasin Location Dworshak Dam is located in the northwest quadrant of the Clearwater Subbasin, within the Nez Perce Indian Reservation.
Dworshak Dam Statistics * Located on North Fork Clearwater River at River Mile 1.9. * 717 feet high. * Highest straight-axis concrete dam in the W. Hemisphere * Third highest dam in the US.
54 miles long at full pool (1600 ft msl) 19,824 surface acres-175 miles shoreline 3,453,000 acre-feet gross storage 2,000,000 acre-feet active storage, Reservoir Statistics
No Fish Passage Lower North Fork Upper North Fork ACCESS Clearwater Subbasin
Blocked by Dworshak Dam n 25% (2440 square miles) of the total Clearwater Subbasin area. n 60% of the steelhead spawning area in Clearwater Subbasin n 1.5 million square yards of steelhead spawning habitat n 1.3 million square yards of chinook salmon spawning habitat
Dworshak Operations n Operated by US Army COE n Authorized Project Purposes –flood control –hydropower –in-reservoir navigation n Also operated for –recreation, water quality, reservoir fisheries, and listed anadromous fish
Proposal Objectives n n Refine the Dworshak Rule Curve Evaluation Model (DRCEM). n n Identify and update appropriate integrated rule curve (IRC) operations. n n Institute appropriate integrated operations. n n Develop a comprehensive long-term M&E Plan for Dworshak Reservoir.
Integrated Rule Curves - A Definition n Integrated Rule Curves (IRCs) are a family of rules for dam operation that incorporate incremental adjustments to allow for uncertainties in water availability. n IRCs serve a spectrum of operational needs.
Development of DWR Integrated Rule Curves n Requisites –Understanding of multi-purpose needs –Coordination with entities with expertise and public responsibilities to serve these needs –Use of available tools to effectively evaluate alternatives and tradeoffs
Defining Individual DWR Rule Curves n Integrated rule curve development first requires the definition of individual operational rule curves for the various needs served by the project, including: –flood control –recreation –hydropower –navigation –resident fish, anadromous fish, wildlife, cultural resources
Individual Rule Curves n Following is a series of graphs intended to define rule curves for specific needs and project purposes n Rule curves need to be minimally defined as elevations or discharges n The following curves are based on operational criteria currently defined by the appropriate regulating and operating entities and other experts
No flood storage space needed July 1 - September 1. 1586 on Oct 1 1579 on Nov 15. 1558 on Dec 15. Max drawdown on April 1 based on run-off forecasts after Jan 1. DWR Flood Control Rule Curve
Depicts operations prior to BIOP flow augmentation for listed salmon. Described and modeled as SOR Alternative 1b (optimum load- following). Minimal summer draft. DWR Hydropower Rule Curve
June - August peak recreation. 1590 most sites usable. Minimum elevation 1590 June 1 - September 1. Default to f.c. rule curve during other periods. DWR Recreation Rule Curve
Log dumps are effectively operational from June 15-Sept 15. Log dumps are effectively operational at 1595. Default to f.c. rule curve during other periods. DWR Navigation Rule Curve
1600 June-October Stable pool as long as possible to minimize erosive impacts. f.c. rule curve Nov- May. (per discussions with NPT Cultural Resources Department) DWR Cultural Resources Protection
1600 June-October. f.c. rule curve Nov- May. (Criteria from Alternative 4c in 1995 SOR - considered fish habitat and reservoir food production.) DWR Resident Fish Rule Curve
Hydro Models Hydrosim HYSSR Genesis DWR Elev. Flows Food Production Bull trout forage (redside shiner) production Bass spawning/inc/ rearing DWR Volume Surf Acres SOR MODEL Habitat Suitability Bull trout Smallmouth Bass Kokanee Kokanee Entrainment Fish Index Value
Light Temp Reservoir Area Shore Area River ( inflow ) Terrestrial Input Outflow Phytoplankton Zooplankton Benthic Insects Terrestrial Insects Fish Growth or Index Dworshak Rule Curve Evaluation Model Schematic
Draft to 1520 by August 31. Refill to flood control rule curve by December 15. Default to f.c. rule curve during other periods. Refill as soon as possible late spring. DWR NMFS BIOP Rule Curve
NMFS BIOP 2000 Update n NMFS is calling for an evaluation of the benefit to listed stocks of an additional 20-feet of Dworshak drawdown in late summer/early fall. n Increases the challenge to achieve meaningful multi-purpose integration of operational needs. n Greater departure from normative conditions for the Clearwater system.
Challenges to IRC Operations n Recreation, navigation, resident fish, flood control and power have generally similar rule curves. (Power has more aggressive fall drawdown.) n BIOP summer drawdown of 80 feet by August 31 is adverse to recreation, navigation, resident fish, power and cultural resources.
Summary n Flood control requirements are hard constraints affecting pool elevation and discharge. n BIOP flow targets are behave like hard constraints affecting pool elevation and discharge. n Spring flood control operations may conflict with spring BIOP flow targets.
Summary (cont.) n BIOP spring flow targets may compete with desired BIOP summer flow conditions. n BIOP summer drawdown adversely affects other project needs including power, navigation, recreation, resident fish and cultural resources. n Power emergencies trump everything else.
Summary (cont.) n Relaxing of flood control space requirements would decrease the conflict between spring flood control operations and BIOP spring flow targets (and benefit other project needs). n Increased spring discharges while assuring refill will generally require less draft for flood control, especially during medium to high water years.
Monitoring and Evaluation Comprehensive Plan bull trout kokanee water quality entrainment zooplankton nutrients benthos fisheries BIOP 2000 cultural resources recreation cutthroat trout introgression modeling impacts