STRATEGIC PRIORITY: Transportation & Infrastructure
AGENDA DATE: June 22, 2022
COUNCIL DISTRICT(S): 9
DEPARTMENT: Water Utilities Department
EXECUTIVE: Kimberly Bizor Tolbert
______________________________________________________________________
SUBJECT
Title
Authorize an increase in the construction services contract with Rebcon, Inc. for additional work associated with the White Rock Lake Dam and Spillway Maintenance Improvements Project - Not to exceed $543,030.65, from $5,997,105.00 to $6,540,135.65 - Financing: Water Capital Improvement G Fund
Body
BACKGROUND
The White Rock Lake Dam and Spillway was originally constructed in 1911 and today includes an approximately 47-foot tall earthen embankment and 450-foot long concrete overflow spillway. The dam is operated and maintained by Dallas Water Utilities (DWU) and is regulated by the Texas Commission on Environmental Quality. As part of regulatory requirements, DWU performs monthly, annual, and five-year regulatory inspections to assess the condition of the dam and recommend maintenance repairs, additional monitoring measures, operational improvements, or risk mitigation strategies. In December 2016, a White Rock Dam Safety Inspection Report was completed that recommended several maintenance repairs to improve the condition of the dam and protect the critical infrastructure asset.
On September 23, 2020, City Council authorized a construction contract with Rebcon, Inc. to perform the recommended maintenance of the dam and spillway, including structural concrete repair to the stop log channels and spillway slabs, replacement of broken concrete on the waterside face of the earthen embankment, slope protection on the land side of the earthen embankment to control erosion, and vegetation removal at the base of the dam to allow for maintenance access and inspection and to prevent invasive roots from impacting the integrity of the dam. In addition, grout injection, concrete joint sealant replacement, and painting of the parapet wall along the top of the dam were included in the proposed improvements.
During construction, the contractor lowered the water level in White Rock Lake to allow personnel and equipment to access areas of the dam and spillway that are normally underwater or have limited accessibility due to the flow of water. The contractor assisted DWU and the project engineer to safely investigate conditions of the existing concrete and confirm the extent of needed concrete replacement. As a result of the investigation, the engineer recommended additional concrete replacement on the dam revetment wall, in the spillway channel, and along the ogee weir. In addition, the concrete channels that hold the wooden stop logs were recommended to be replaced to allow for the installation of the new aluminum stop logs. Under the supervision of DWU, the concrete repairs were completed, and the dam and spillway were placed back in service as lake levels returned to normal. The extended repairs consisted of the removal and replacement of 184 additional 20-foot by 20-foot reinforced concrete panels.
This action will authorize an increase in the construction contract for the removal and replacement of additional concrete to ensure the dam and spillway continue to safely serve City of Dallas residents and visitors to White Rock Lake.
ESTIMATED SCHEDULE OF PROJECT
Began Construction November 2020
Completed Construction February 2022
PRIOR ACTION/REVIEW (COUNCIL, BOARDS, COMMISSIONS)
On September 23, 2020, City Council authorized a construction contract with Rebcon, Inc. for the White Rock Lake Dam and Spillway Maintenance Improvements Project by Resolution No. 20-1469.
FISCAL INFORMATION
|
Fund |
FY 2022 |
FY 2023 |
Future Years |
|
Water Capital Improvement G Fund |
$ 543,030.65 |
$0.00 |
$0.00 |
Construction $5,997,105.00
Change Order No. 1 (this action) $ 543,030.65
Total Project Cost $6,540,135.65
M/WBE INFORMATION
In accordance with the City’s Business Inclusion and Development Policy adopted on September 23, 2020, by Resolution No. 20-1430, as amended, the M/WBE participation on this contract is as follows:
|
Contract Amount |
Procurement Category |
M/WBE Goal |
M/WBE % |
M/WBE $ |
|
$543,030.65 |
Construction |
25.00%* |
12.99% |
$70,541.80 |
|
• *This item reflects previous Business Inclusion and Development Policy M/WBE goal. |
|
• This contract does not meet the M/WBE goal, but complies with good faith efforts. |
|
• Change Order No. 1 - 6.81% Overall M/WBE Participation |
|
• Rebcon, Inc - Local; Workforce - 38.00% Local |
OWNER
Rebcon, Inc.
Mark Gaines, Vice President
MAP
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