Topic:
Consider and take action on a resolution authorizing a Work Change Directive #2 to the construction contract of C4 Partners, LLC related to the Bay Ridge Flood Reduction - Phase 2 (DR 2005), in an amount not to exceed $247,363.75 (Executive Director of Capital Projects)
Background:
Approval of this resolution will authorize funding for a Work Change Directive #2 (WCD #2) to the construction contract of C4 Partners, LLC related to the Bay Ridge Flood Reduction - Phase 2 (DR 2005).
The proposed Work Change Directive is being requested in support of the drainage project DR 2005 - Bay Ridge Flood Reduction - Phase 2, currently under construction, to relocate the transformer, add additional electrical conduits, and add rock riprap at the outfall. During design phase, the City, consultant, and Texas-New Mexico Power (TNMP) conducted a series of TEAMS meetings to discuss the location of the transformer and other possible conflicts and coordination. TNMP’s determined that the original location of the transformer was suffice.
However, during construction, when City staff coordinated with TNMP on the proposed location of the transformer as shown in plans and spotted in the field, the TNMP staff determined that area around the transformer pad is too narrow for service and maintenance by them as well as the City. They recommended moving the pad to a more open area which is farther. Options were considered for this relocation before location was finalized. The contractor must run approximately 100 feet of 3 - 3-1/2” conduits and wiring embedded in concrete encasement, install a new 4’x4’x4’ junction box, saw cut, remove and replace a section of concrete driveway pavement, to complete this relocation. Additionally, to bring power into site, approximately 550 feet of 2 - 6” conduits and conductors in a direct bury trench is needed between TNMP power pole and the transformer.
WCD #2 also includes unforeseen weather-related additional pump-down hours, above the allocated hours in the bid, to keep the pond volume down during rain events to avoid backups into the neighborhood streets.
In addition, at the existing detention pond outfall, it was determined that the accumulation of silt in the Duckbill Valve is mainly due to migration of silt into pipe and valve from the undercutting of the Gum Bayou channel. This caused valve not to function properly during storm events. Placement of rock riprap would reduce or eliminate undercutting of the channel. Therefore, City staff recommended the placement of riprap on geotextile fabric to stabilize the channel bottom. This outfall location will eventually be further improved under the future Bay Ridge Phase 4 project which includes, among other things, the deepening and widening of the Gum Bayou.
The total add-ons and modifications from above items, as shown in Attachment 3, is $382,751.75. However, project’s base bid and extra work items sections have number of construction items which staff has determined are not needed. As shown in Attachment 3, these total up to $135,388.00 which results in WCD #2 amount of $278,243.75.
This project has an approved contingency of $700,000, of which $228,797.00 was approved by Council on April 25,2023 to fund Work Change Directive #1, authorized to reroute an existing sanitary sewer line which was in conflict with the pump station structure.
Attachments:
1. Data Sheet
2. Proposed Resolution
3. Proposed WCD #2 and C4 Partners, LLC Change Order Cost Estimate
4. Copy of Approved WCD #1
5. Exhibits of Transformer Relocation
6. Aerial Map of Bay Ridge Subdivision
FUNDING
{X} Total funding in the amount of $247,363.75 is available from construction contingency, Fund 5270, with expenses charged to project expense string DR2005-CONSTRUCT-CONSTRUCT- 21PROPA.
STRATEGIC PLANNING
{X} Addresses Strategic Planning Critical Success Factor #1: Develop and Maintain our Infrastructure.