REQUEST FOR PROPOSAL BRUNSWICK COUNTY COUNTY PARK AT GREAT CREEK DAM #6A PROFESSIONAL ENGINEERING SERVICES JANUARY 2010
Brunswick County, Virginia will accept proposals for professional engineering services to assist the county with compliance with the Virginia Dam Safety Regulations. Great Creek Dam 6A is a 65 foot high, 1370 foot high earthen dam providing both flood control and water supply for Brunswick County and the Town of Lawrenceville, Virginia. Brunswick County currently owns and operates Great Creek Dam 6A under a six year Regular Operation and Maintenance (O&M) Certificate issued by the Virginia Soil and Water Conservation Board, effective January 20, 2006, and scheduled to expire January 31, 2012. These professional engineering services include spillway design flood development, spillway capacity analysis, dam break analysis and inundation zone mapping for Great Creek Dam 6A. A copy of the Scope of Services is available by contacting Ms. Charlette T. Woolridge, Brunswick County Administrator, 434-848-3107.
The purpose of this RFP is to solicit the input of firms in making recommendations on how to best meet the needs of Brunswick County in assuring Great Creek Dam 6A is in compliance with state regulations. Great Creek Dam 6A is currently classified as a high hazard dam with a required spillway flood design equal to the probable maximum flood. As mentioned above the O&M Certificate will expire January 31, 2012. Prior to application for a new Operation and Maintenance Certificate, a dam break analysis and inundation zone mapping will need to be performed in accordance with dam safety regulations. Ninety (90) days prior to the expiration of the current Operation and Maintenance Certificate Brunswick County will be required to apply for a new O&M Certificate which involves submission of an O&M Certificate Application form, O&M Plan and Schedule, Emergency Action Plan (EAP), and an Annual Inspection Report to Virginia Department of Conservation and Recreation.
Those submitting proposals shall list on a separate sheet of paper any variations from or exceptions to the conditions and specifications of this proposal. This sheet shall be labeled “Exception(s) to Proposal Conditions and Specifications” and shall be attached to the proposal.
Award of this project is dependent on approved funding from the Brunswick County Board of Supervisors.
Submit Request for Proposal to Charlette T. Woolridge, County Administrator, Brunswick County Administrator’s Office, P.O. Box 399, Lawrenceville, Virginia 23868 no later than 1:00 p.m. on February 3, 2010.
1 Submitting Proposal: Each proposal shall be submitted in a separate sealed envelope and shall contain seven (7) copies of the following information as a minimum.
Completed Proposal Form
Narrative describing proposal
List of references with contact information
List of related projects
Review of Proposals: The proposals received will be referred to a committee for review, evaluation and recommendation to the Brunswick County Board of Supervisors.
Evaluation of Proposals
FACTORS WEIGHTED VALUE CONSIDERATIONS Cost 30% Total not to exceed $______
Experience 20% Years of Service/Related Projects
Proposal Meeting 50% Compared to minimum Scope of Services specifications
Scoring System
Proposals rated relative to Scope of Services and other proposals
1 Lowest 2 3 4 5 Highest
Minority business enterprises are encouraged to respond to this solicitation notice.
2 The Brunswick County Board of Supervisors, Brunswick County, Virginia reserves the right to reject any and all proposals, to waive any informality, or to select the firm best suited for or in the best interest of Brunswick County.
______Charlette T. Woolridge County Administrator Brunswick County, Virginia
3 Proposal Form for Engineering Services
We, ______propose to provide engineering services in accordance with the Scope of Services as set forth by Brunswick County, Virginia for the terms generally described below:
Cost: $______
Proposal Submitted By:
Signature:______
Printed Name:______
Title:______
Address:______
______
Telephone:______
Fax:______
Email:______
Date:______
4 SCOPE OF SERVICES
Great Creek Dam 6A is currently a high hazard dam and the required spillway design flood will be the full probable maximum flood.
In accordance with the Virginia Dam Safety regulations, the hydrologic and hydraulic modeling and inundation zone mapping shall extend to a point downstream where the water-surface elevation of the spillway design flood with and without dam failure converge to within one foot of each other or to a point at which the probabl maximum flood with a dam failure creates possible damage to a structure, whichever is the farthest downstream. Based on these criteria it is anticipated that the limit of study will begin at Great Creek Dam 6A and end at the confluence of Great Creek and the Meherrin River for a total reach length of approximately nine (9) miles.
Best available existing topographic base mapping and field survey data may be used as the basis for all hydrologic and hydraulic anaylsis. This may include as-built plans for Great Creek Dam 6A, Brunswick County or Town of Lawrenceville topographic mapping, 10 foot contour interval USGS quadrangle maps, or terrain data from the Virginia Geographic Information Network (VGIN).
Estimates of the lake storage volume below normal pool may be based on existing records available from either the Natural Resources Conservation Service or the Virginia Department of Conservation and Recreation Division of Dam Safety.
Data Collection and Field Reconnaissance Data necessary to perform hydrologic and hydraulic analysis for this project will need to be collected. This data may include as-built construction plans for the dam, available topographic or digital terrain data for the watershed and downstream inundation zone, available Natural Recource and Conservation Service design data for the dam, Virginia Department of Transportation roadway and bridge plans for hydraulic structures within the inundation zone, and FEMA floodplain data for Great Creek. The following agencies should be contacted to obtain relevant data: . Virginia Department of Natural Resource and Conservation to review their files and collect relevant data concerning the dam. . Brunswick County staff to obtain any available base mapping data suitable for the dam breach inundation mapping. . Virginia Department of Transporation to obtain as-built plans for existing bridge or culvert structures crossing Great Creek below the dam. 5 . Federal Emergency Management Agency to obtain the effective hydraulic model and floodplain work maps for Great Creek, if available. . Virginia Geographic Information Network to obtain digital terrain data of the Great Creek watershed and inundation zone below the dam, if available.
Spillway Design Flood Development and Spillway Capacity Analysis Hydrologic and hydraulic analysis is required to compute the spillway design flood and assess spillway capacity for Great Creek Dam 6A. A hydrologic model of the Great Creek watershed above Great Creek Dam 6A is required. This model will be used for spillway design flood development and flood routings. Natural Resources Conservation Service procedures and guidelines outlined in Natural Resource Conservation Service TR-60 for development of the probable maximum flood should be followed. The hydrologic model will be used to develop probable maximum flood inflow and outflow hydrographs and compute the available spillway capacity in terms of a percentage of the probable maximum flood. The results of this task should be summarized in a report describing the hydrologic and hydraulic procedures used to assess spillway capacity.
Dam Break Analysis and Inundation Zone Mapping Dam break analysis and inundation zone mapping is required along the assumed limit of study. The hydrologic model above Great Creek Dam 6A will need to be extended downstream to the assumed study limit. Water- surface elevations associated with dam breach and no dam breach scenarios will need to be computed using appropriate hydrologic and hydraulic modeling techniques. In accordance with section 4VAC50-20-54 of the Virginia Dam Safety Regulations the following flooding scenarios should be analyzed and the associated inundation zones mapped: 1) sunny day dam breach; 2) spillway design flood with dam breach and; 3) spillway design flood without dam breach. As stated previously the probably maximum flood is assumed to be the required spillway design flood for Great Creek Dam 6A. After review and evaluation of the sunny day and probable maximum flood dam breach inundation zones, a determination should be made to confirm whether or not the high hazard classification for Great Creek Dam is appropriate and whether or not the full probable maximum flood is the appropriate spillway design flood. The inundation zone flood limits for the three scenarios described above should be depicted in plan and profile format in accordance with recommended mapping criteria set forth by Virginia Department of Conservation and Recreation Division of Dam Safety. The results of this task should be summarized in a report describing the procedures and engineering methodology used to perform the dam break analysis and inundation zone mapping. The dam breach inundation zone mappping (plan and profile) should be included as an attachment to the summary report. 6 Preparation of the O&M Certificate Application form.
Preparation of the O&M Plan and Schedule.
Preparation of the Emergency Action Plan (EAP).
Preparation of the Annual Inspection Report.
Site visit(s) necessary to inspect the dam structure, spillway and related areas and to meet with staff and other individuals.
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