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HomeMy WebLinkAboutTerraSond Proposal October 7, 2008 Brian Hirsh Energy Program Manager Yukon River Inter-Tribal Watershed Council (YRITWC) 725 Christensen, Suite 3 Anchorage, AK 99701 Subject: Phase one of the Hydrokinetic Power Generation Feasibility Study at Ruby, Alaska Dear Mr. Hirsh: Terrasond Ltd. is pleased to submit the following proposal for the Yukon River Hydrokinetic Test Site in Ruby, AK. All instrument surveys will conform to accepted industry standards and practices and would be supervised and approved by our geophysical staff and a Registered Alaska State Professional Land Surveyor. Proposed Goals and Methodology The goal for Phase one of the Hydrokinetic Power Generation Feasibility Study will be to accomplish a preliminary reconnaissance of the Yukon River in the vicinity of the town of Ruby, Alaska for the purpose of identifying the most advantageous location to install hydrokinetic turbines for power generation. Once the initial single beam echosounder (SBES) data and the preliminary Acoustic Doppler Current Profiles (ADCP) are collected, TerraSond will process a sparse infield bathymetric surface and three (3) current flow transects with depth-quantized vector diagrams as reference. TerraSond will consult YRITWC and other interested stakeholders during presentation of this preliminary data as the most advantageous site location is determined. Once YRITWC has selected the (or limited number of) candidate site(s), TerraSond will focus all future efforts upon this selection. Additional ADCP data will be gathered if necessary. A multibeam echosounder (MBES) will be used to acquire a dense spatial dataset of the candidate site location(s) for processing of a detailed baseline surface at the TerraSond Processing Center. This product, geomorphologic interpretations, hazards to construction and navigation, and all conclusions will be presented in the final project report. Execution of Project TerraSond will prepare and mobilize for this effort on a mutually agreed upon high-water event coordinated with YRITWC. At this time, TerraSond believes that a realistic target expedition would occur soon after break-up. Survey control work will include the recovery of USGS monumentation, if available, and incorporation into our overall GPS survey network. The installation of TerraSond control will include a minimum of two new control points. Unless otherwise directed, TerraSond intends to identify and adopt the USGS vertical datum for all products and computations allowing for direct reference with river level history and published values by USGS existing infrastructure. TerraSond will ship a survey vessel of our own to the project location or we will obtain an acceptable vessel of opportunity at the project location and convert it to a survey vessel. The work will include one river discharge measurement in the vicinity of the hydrokinetic site. The site for this measurement will be chosen by TerraSond as necessity dictates to ensure the best and most accurate discharge measurement. Three (3) bi-directional transects will be accomplished providing both flow and direction measurements at ~1000m intervals. These transects will include bathymetry, flow and direction measurements presented as cross sectional imagery and vector diagrams. Full bottom coverage (MBES) bathymetry will be acquired once YRITWC determines which site specific location is chosen to best suit their needs for the Hydrokinetic test site. If schedule permits and assuming that the primary goals for this project are not at risk, TerraSond intends to be responsive to YRITWC for unplanned locations of interest or opportunities that present for gathering data while in the field within the project boundary. If the river water-level changes significantly while TerraSond is onsite, TerraSond will attempt to accomplish an additional discharge measurement with co-located current flow and direction measurements further expanding YRITWC’s understanding of the river and the variables which will determine power production. TerraSond will attempt to accomplish this work if time permits, however, it is unknown at this time how much can be accomplished in the time allotted for this project. TerraSond will try to accomplish as much as possible during the duration while onsite for YRITWC. The resulting products from this work effort will be: ! Establishment of TerraSond monumentation including detailed description of geodetic control used during this project. ! Sparce, but extensive bathymetry of the Yukon in the region of Ruby, AK. ! Representative river flow cross section graphic (for each transect accomplished). ! Vector graphic of current direction at peak flow depth (for each transect accomplished). ! Discharge computation and direct comparison to USGS value. ! Bathymetric dataset with high resolution (MBES) detail area(s). ! Project Report w/ interpretation and conclusions Equipment A minimum four cross sectional current flow measurements will be acquired with a 1200KHz Acoustic Doppler Current Profiler (ADCP) along the Yukon River at the sites listed above. This information will provide both flow velocity and flow direction information throughout the water column. The preliminary target site(s) will be provided by YRITWC and all additional sites for current measurement will be derived from the bathymetry, geomorphology, and focused upon areas of the river where the depths are acceptable for hydrokinetic power production or where holistic evaluation of the river volume is advantageous. A discharge measurement will be calculated using this same instrumentation for the river during this phase of the project for direct relationship to the river current vector information. If a moving bottom is identified this information will be quantified and calculated out of the final computation products according to USGS procedure or the ADCP vector information will be excluded from the final computations. This survey will also accomplish bathymetric transects of the Yukon River in the vicinity of the town of Ruby with an 16 foot inflatable with a custom-built survey structure outfitted with a 3° Singlebeam Echosounder (SBES) by acquiring cross-section transects at ~100m intervals along the river 1200 m upstream and 1200 m downstream of the town boundaries. Cross lines will be acquired along and at the foot of the thalweg for data QC purposes. TerraSond intends to run additional transects when deemed appropriate to ensure a quality surface product (i.e. specific deep areas identified during the field acquisition and near bends or angular transects). MBES will be an ODOM ES3 240 kHz 480 beam with 120 degree swath capability. This system will incorporate a Coda F-180 inertial navigation system to accurately position the swath bathymetric data. All Geodetic equipment for this portion of the project will be accomplished with Trimble GPS instrumentation. A permanent monument will be established by TerraSond for geodetic control, quality control and repeatability, and for future efforts related to this project. TerraSond will establish a Real-time Kinematic (RTK) base station which will broadcast GPS corrections throughout the survey duration significantly reducing the rover positional error in both the horizontal and the vertical dimensions. Cost The information listed below is the budgetary cost for this project. Yukon River at Ruby ADCP, Singlebeam and Multibeam Project Preparation Preparation (1 day at standby) $ 3455 Shipping time and cost for all equipment Anchorage to Ruby $ 2500 Sub Total Preparation Effort $ 5955 Field Effort ADCP and SBES Travel (1 day at standby includes RT airfare between Anchorage and Ruby) $ 5455 Control/Topography/Install (1 day) $ 3728 Survey Singlebeam and ADCP (2 days) $ 7935 Sub Total Field Effort ADCP and SBES $ 17118 Field Effort MBES Survey Multibeam detail areas (one day) $ 4718 Sub Total Field Effort MBES $ 4718 Demob from Ruby Travel (1 day at standby/ RT airfare accounted for in mob) $ 3455 Shipping time and cost for all equipment Ruby to Anchorage $ 2500 Sub Total Demob $ 5955 Office Effort Process Control and Topography (8 hours Senior Tech) $ 960 ADCP/Singlebeam Processing (20 hours Professional) $ 2570 Multibeam Processing (8 hours Professional) $ 1370 Drafting (8 hours Senior Tech) $ 960 Reporting (8 hours Professional) $ 1120 Sub Total Office Effort $ 6980 Project Total $ 40726 By nature, the Yukon River is a dynamic environment, the information gathered during this survey is only valid during the event of this project, any spatial/ temporal interpretations or extrapolations can not be considered reliable. Please feel free to contact me if you have any questions about the project scope or costing for this project. I wish you and your project great success, Brian. Best Regards, David Oliver Geophysicist TerraSond Ltd Terrestrial and Seafloor Mapping 1617 South Industrial Way Suite 3, Palmer, Alaska 99645 (907) 745-7215 x114 Office (907) 715-8144 Mobile www.terrasond.com cc: TJ Howland, Hydrographic Program Manager