Sullivan Lake Cold Water Intake. Pend Oreille PUD No. 1 of Pend Oreille County, WA

Transcription

1 Sullivan Lake Cold Water Intake Pend Oreille PUD No. 1 of Pend Oreille County, WA April 7, 2016

2 Project Location Sullivan Lake

3 Project Location Pend Oreille River Sullivan Lake

4 Project Team Project Team Owner: Pend Oreille PUD No.1 of Pend Oreille County, WA Engineer: McMillen Jacobs Associates Contractor: Karnath Contracting, Inc.

5 Project Background Project Goals Lower creek temperatures downstream of the dam to improve native bull trout habitat through cold water releases during summer months Limited rehabilitation of existing dam and gates Original timber crib dam built in 1909 Concrete dam constructed in 1923 and refurbished in 1994

6 Project Background Major Project Features Reservoir Intake Cofferdam Cold Water Pipeline Dam Penetration and Discharge Control Gate Control Building and Air Burst System

7 Project Design Criteria Design Criteria Maximum Design Flow: 160 cfs Max WSEL: Min WSEL: Screen Centerline EL: Pipeline Inside Diameter: 47.5-in (HDPE) Screen Opening Size: 1/16 Slot Screen Approach Velocity 0.4 ft/s Screen Cleaning: Air Burst System

8 System Operation System Operation Outlet and Sullivan Creek temperature and flows are recorded by instream sensors Temperature and flow data is sent back to the control building via radio PLC performs mass balance equation for desired blended temperature PLC modulates discharge gate position as required

9 Site Map Outlet Creek USFS Compound Dam Control Building County Bridge Airstrip Intake Location Boat Launch Sullivan Lake

10 Project Site

11 Project Site

12 Project Site

13 Construction Sequence Control Building Buried Pipeline Sunk Pipeline Intake Cofferdam

14 Pipeline Profile and HGL Max WSEL Min WSEL Discharge Gate Screen CL EL

15 Intake Design Characteristics Screen Structure Twin 6-ft diameter by 16.5 ft long tee style screens connected on a common header Supported on piles driven into reservoir bottom

16 Intake Air Burst System Air Burst System Air lines travel from control building to tee screens Each tee screen has it owns air burst line Burst of air travels through the line and the out of the screens to remove debris Screens are cleaned based on head differential Always manually activated to ensure no boaters are present

17 Intake Tee Screens

18 Cofferdam Cofferdam Placed to allow approach channel pipeline section to be installed in the dry Sheet pile vibrated into place U-shape to minimize overall length Bypass system required for 10cfs after installation

19 Cofferdam - Installation

20 Cofferdam Installation

21 Cofferdam Installation Complete

22 Pipeline Design Characteristics Cold Water Release Pipeline Constructed from 54 OD HDPE (DR 17 Approx. 3 thick walls) Two Distinct Sections Buried in approach channel (installed in the dry) On reservoir bottom from approach channel to intake (sunk in place) Concrete collars hold the pipeline in place Twin 10 HDPE air burst pipelines follow alignment

23 Pipeline Fusing

24 Pipeline Staging

25 Pipeline Floating

26 Pipeline Positioning

27 Pipeline Dry Installation

28 Pipeline Air Burst Piping and Backfill

29 Pipeline Floating

30 Pipeline Positioning

31 Pipeline Sinking

32 Dam Penetration & Discharge Control Gate Dam Penetration Transition from HDPE to steel 46-in square steel liner in existing concrete outlet channel Discharge Control Gate Fabricated stainless steel slide gate for throttling Flange connection to square steel liner Automated to control releases

33 Dam Penetration & Discharge Control Gate

34 Dam Penetration & Discharge Control Gate

35 Dam Penetration & Discharge Control Gate

36 Control Building Design Characteristics Control Building Houses air burst cleaning system equipment, electrical, and control systems Air burst system includes: Twin 5 hp compressors 6,000 gallon air receiver 8-in stainless steel piping and control valves Built next to historic bunk house on USFS compound

37 Control Building Site Development

38 Control Building Air Receiver Installation

39 Control Building Air Piping

40 Dam Rehabilitation Dam Rehab Items: Patched spalling concrete and armored pier noses Concrete deck overlay Replaced low level outlet gates Added electric actuators for upper gates Replaced existing handrail

41 Dam Rehabilitation Low Level Gates

42 Dam Rehabilitation Deck Overlays

43 Dam Rehabilitation Historic Handrail Replacement

44 Project Challenges Construction on and around historic structures Determining where to stop repairs on the dam Control building location and aesthetics Existing timber crib dam Site geotechnical: Varying reservoir bottom conditions Cofferdam Location Dewatering challenges Site Recreation Requirements Small in-reservoir work window

45 Existing Timber Crib Dam Discovery

46 Existing Timber Crib Dam Discovery

47 Existing Timber Crib Dam Discovery

48 Existing Timber Crib Dam Discovery

49 Existing Timber Crib Dam Discovery

50 Existing Timber Crib Dam Discovery

51 Air Burst in Action

52 Questions? William Zimmerman, PE McMillen Jacobs Associates