New Hydro without a new Dam NWHA FEBRUARY 16, 2016

Transcription

1 New Hydro without a new Dam NWHA FEBRUARY 16, 2016

2 Agenda Background Perceptions & Misconceptions about Hydro Legislative Environment Snohomish PUD s search for new Hydro resources Sunset Project Overview Trap-and-Haul Mitigation Dam-free design Conclusions

3 Mis-Conceptions of Hydroelectric Projects All hydroelectric projects are detrimental to fish. All hydroelectric projects require big dams that alter the river ecosystem (fish blockage, sediment/wood transport)

4 Recent Studies and Legislation on Hydropower Development TRANSLATION: Projects that don t require a new dam are given a faster path towards approval (not greenfield)

5 Snohomish PUD Low Impact Hydro Assessment Identified 145 sites in 4-County area Review Criteria: Upstream of or at a natural barrier to anadromous fish Outside Federal Wilderness & Federal Wild and Scenic River designations Near transmission Outreach: with Federal and State agencies, tribes and NGOs

6 Using existing dams case study

7 Can a hydroelectric project be a win-win for fish? Existing Trap & Haul Facility

8 Sunset Trap & Haul Facility Site sold by private utility in 1951 Trap built in 1958, operated by WDFW Originally a temporary facility, fishways proposed at all three falls 1965, decided fishways too expensive, recommended upgrades (never completed) Operates from July to December Eight species of salmonids passed including Chinook, coho, chum, pink, sockeye, steelhead, bull trout, and cutthroat Fish are transported 4 miles around Sunset, Canyon and Eagle falls Provides access to over 90 miles of habitat upstream Accounts for 20% of production in Snohomish Basin

9 If you can t find an existing dam, how about not using one?

10 Sunset Project - Overview Facility Capacity / Output Average / Output Impoundment Weir/Dam/River Barrier Intake Tunnel Powerhouse Tailrace Transmission line Footprint Bypass reach Overview Details 30 MW 13.7 MW None None 2,500 cfs maximum diversion, Trash rack and bays of fish screens in a V-shaped arrangement, fish bypass pipe discharging down-stream of the diversion Underground, horseshoe-shaped; 22-foot diameter for 600 feet, then 19-foot diameter for 1,500 feet Semi-underground, twin 15 MW Vertical Kaplan turbines and generators 15 feet high by 30 feet wide, underwater 115kV overhead line to be overbuilt mostly along the existing distribution line on US 2, ~8.5 miles to existing Gold Bar substation Less than 4 acres, with much of that underground 1.1 miles (approximately between river mile

11 Intake Location 1954 Pool and Control Point 2006 Pool and Control Point

12 Sunset: Debris transport 12 Per bathymetry, review of historic aerial imagery and refinement of rating curve, no weir is required Flow regulation via powerhouse control Natural stable control point downstream maintains deep pool, self-cleaning at high flows Hydraulic constriction at Eagle Falls limits sediment transport into the downstream reach Operation would cease at flows >8,000-cfs

13 Bathymetry & Sediment Transport 13

14 Overview - Section

15 Conclusions Prior era dams were developed with impacts to migrating fish and biodiversity that left a negative stigma for the general public With effective mitigations and efforts to make a project low-impact, hydroelectric projects can avoid negatively affecting fish With the right opportunity new hydro can be built without the need for a new dam. Hydropower has its place in renewable portfolios as a cost-effective resource.