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.
Submitting Proposal: Each proposal shall be submitted in a separate sealed
envelope and shall contain seven (7) copies of the following information as a
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
Evaluation of Proposals
Total not to exceed
Years of Service/Related
Proposal Meeting
Scope of Services
Compared to minimum
Scoring System
Proposals rated relative to Scope of Services and other proposals
Minority business enterprises are encouraged to respond to this solicitation
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
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:
Proposal Submitted By:
Printed Name:___________________________________
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
 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
Federal Emergency Management Agency to obtain the effective
hydraulic model and floodplain work maps for Great Creek, if
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. Watersurface 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
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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