AWRA National Conference Portland, Oregon,November 7, 2013

Transcription

1 AWRA National Conference Portland, Oregon,November 7, 2013 Analysis of Floodplain Reconnection and Habitat Enhancement on Okanogan and Similkameen Rivers Felix Kristanovich, PhD, PE, ENVIRON - Seattle Domoni Glass, ENVIRON - Olympia Erica McCormick, ENVIRON - Portland Greg Reub, ENVIRON Olympia

2 Town of Oroville Site Locations NE Washington State Similkameen River Okanogan River Town of Tonasket

3 Project Goals To identify areas for potential re-activation of floodplain or relic channels (outside main-stem river) To induce deposition of fine sediment in newly formed areas To provide high flow refugia for juvenile rearing in reactivated channels To enhance main-stem spawning

4 Methodology Site reconnaissance Coordination with Tribe Preliminary Analysis (hydrology, biology, feasibility) Site Surveying Selection of final 4 sites Hydrologic and Geomorphologic (Channel Migration) Analyses HEC-RAS, HEC- GeoRAS, GIS programming Design of diversion channels Biological Evaluation (Benefits for Fish)

5 Methodology Hydrology: USGS flow data for gages at Oroville and Tonasket; USGSS program PEAKFQ to calculate floods Hydraulics: Existing Conditions minimum flow for overtopping was found; program run in optimization mode Future/design condition excavation channel designed to enable overflowing at 2-year floods & channel sized to mimic relic channels Geomorphology: Channel migration analysis (historical aerials of 1947, 1954, 1964, 1974, 2011) Sediment Transport & Channel Stability analysis

6 HYDRAULICS AND GEOMORPHOLOGY

7 Site 5

8 Site 5 Design of New Channel Flow Regim e Flows in the river (m3/sec) Flows diverted (m3/sec) Flows overflo wing - existing % of diverted flow Inlet size modeled (HEC- RAS) Outlet Size modeled (HEC- RAS) Volume of cut needed 2-year year 100- year m opening; Invert at 276 m (for 300 m) 40 m opening; Invert at m for 300 m; transitions to 275 m for 16 m Entrance: 19,226 cy; Exit:: 47,000 cy

9 Modeling Results - Site 5 (2-year Flood)

10 Modeling Results - Site 5 (10- year Flood)

11 Modeling Results - Site 5 (100- year Flood)

12 Animation Site 5

13 Site C

14 Site C Design of New Channel Flow Regim e Flows in the river (m3/sec) Flows diverted (m3/sec) Flows overflo wing - existing % of diverted flow Inlet size modeled (HEC- RAS) Outlet Size modeled (HEC- RAS) Volume of cut needed 2-year year 100- year m wide; Invert at m; 78 m long 40 m wide; Entrance: 8,000 cy; Exit: 3,700 cy year

15 Modeling Results - Site C (100- year Flood)

16 Animation Site C

17 Site D

18 Site D Design of New Channel Flow Regim e Flows in the river (m3/sec) Flows diverted (m3/sec) Flows overflow ing - existing % of diverted flow Inlet size modeled (HEC- RAS) Outlet Size modeled (HEC- RAS) Volume of cut needed 2-year year 100- year m. wide; Invert at m; 1H:1V; 58 m long 40 m wide; invert at m; 84 m long Entrance: 11,000 cy; Exit: 20,000 cy) 500- year

19 Modeling Results - Site D (2-year Flood)

20 Animation Site D

21 Site K

22 Site K Design of New Channel Flow Regim e Flows in the river (m3/sec) Flows diverted (m3/sec) Flows overflow ing - existing % of diverted flow Inlet size modeled (HEC- RAS) Outlet Size modeled (HEC- RAS) Volume of cut needed 2-year year 100- year m. wide; Invert at 277 m; 1H:1V; 115 m long 40 m wide; Invert at 274 m; 1H:1V; 173 m long Entrance: 18,000 cy Exit: 27,000 cy) 500- year

23 Modeling Results - Site K (10-year Flood)

24 Animation Site K

25 FISH BIOLOGY

26 Fish migration facts Chinook salmon migrate - August/September - spawn October - emerge from gravel May/June Steelhead migrate August/September -spawn in March-May - emerge from gravel next March May Sockeye - spawn in Fall emerge out April - June Conclusion : Fish migration (small fish) coincides with high flows on Okanogan River (May)

27 Fish Habitat Criteria - review Fish Criteria Source Preferred Depth (ft) Preferred Velocity (ft/sec) Chinook WDFW/WDOE (2008) Raleigh (1986) Hampton (1997) Steelhead (fry) Steelhead (juvenile) WDFW/WDOE (2008) > Hampton (1997) Hampton (1997) <2.0

28 Fish Habitat Criteria this study Accepted Criteria: All water depths > 1 ft (0.3 m) Velocities: Preferred range: Still acceptable: ft/s (0.4 m/s) ft/s ( m/s)

29 Hectares of Habitat available - 2- year 70 2-Year Flow Return Interval 60 Hectares of Habitat Flow (m/s) > Site 5 Site C Site D Site K

30 Hectares of Habitat available-10- year Year Flow Return Interval 100 Hectares of Habitat Flow (m/s) > Site 5 Site C Site D Site K

31 Hectares of Habitat available-50- year Year Flow Return Interval Hectares of Habitat Flow (m/s) > Site 5 Site C Site D Site K

32 Hectares of Habitat available- 200-year Year Flow Return Interval 250 Hectares of Habitat Flow (m/s) > Site 5 Site C Site D Site K

33 SUMMARY RESULTS

34 Site 5 Fish-friendly habitat for Low Floods (2-yr, 10-yr, and 20- yr)

35 Site C Fish-friendly habitat for Low Floods (2-yr, 10-yr, and 20- yr)

36 Site D Fish-friendly habitat for Low Floods (2-yr, 10-yr, and 20- yr)

37 Site K Fish-friendly habitat for Low Floods (2-yr, 10-yr, and 20- yr)

38 Acknowledgements: Chris Fisher and Keith Kistler, Colville Confederate Tribes, Omak, Washington Kathy Dube, Geomorphology

39 QUESTIONS?