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HomeMy WebLinkAbout2026 01 12 Consent 304 - Deer Run Stormwater Control Structure Modification ProjectCONSENT AGENDA ITEM 304 CITY COMMISSION AGENDA | JANUARY 12, 2026 REGULAR MEETING TITLE Deer Run Stormwater Control Structure Modification Project SUMMARY The primary reason for modifying the existing Willow Lake control structure at the Deer Run Subdivision is to prevent continued homeowner access that has resulted in unauthorized, potentially dangerous adjustment to control the lake levels prior to and following a significant storm event. The discharge from this lake outfalls directly to Howell Creek which has a history of flooding and erosion impacts from prior storm events. The homeowners do not have the authority to operate the control structure, and potentially at the detriment of downstream homeowners on Howell Creek. Therefore, the existing control structure boards are to be removed and replaced with an attached aluminum plate, along with an orifice to ensure proper water control elevation and prevent continued unauthorized adjustment to the water levels in the Deer Run pond. The secondary reason for modifying the existing control structure is the removal of the makeshift PVC pipes that were intended to serve as a fish barrier but adversely impacted the water flow through the structure weir openings which has created an ongoing maintenance issue. This modification will lower the existing steel grate while maintaining the intent of the PVC pipes to create a fish barrier during high water events. The City released a formal ITB (ITB 11-25-01 Deer Run Control Structure) on November 12, 2025 and received only one response on December 12, 2025 from Cathcart Construction Company in the amount of $138,162. FUNDING SOURCE The funding for this project was not budgeted for FY26, however due to the timing of other capital projects in the 3rd Generation Sales Tax Fund, this capital project can be funded under the City - Wide Stormwater Rehab project due to urgency of need. RECOMMENDATION Staff requests the City Commission approve a task order for Cathcart Construction Company to provide construction services to modify the existing Willow Lake control structure located within the Deer Run Subdivision in the amount of $138,162. 81 “Engineering a Higher Standard” 301 West State Road 434, Suite 309, Winter Springs, FL 32708 • 407-992-9160 • Fax 407-358-5155 www.pegasusengineering.net P R O J E C T M E M O R A N D U M Submitted To: Kevin Sweet, MPA, ICMA-CM City Manager City of Winter Springs Prepared By: David Hamstra, P.E., CFM Stormwater Department Manager Date: March 13, 2025 (Revised April 14, 2025) Subject: Deer Run Subdivision | Willow Lake Control Structure Pursuant to the City of Winter Springs request, we have prepared the revised attached control structure figure with the proposed scope of work to make the structure less susceptible to being tampered with and reduce the need for continual maintenance work (refer to attached figure). Based on our review of the 1989 construction plans (Sheet 29), as well as our recent site inspections to confirm the current conditions and take measurements, we offer the following observations (refer to attached site inspection photographs): ▪ The existing control structure has weir openings on all four sides whereas Sheet 29 of the original control plans would lead you to believe only three openings were envisioned. It appears that the general difference being the concrete headwall for the 30 -inch outfall pipe was not installed per the 1989 construction plan and what exists today is a typical control structure with various openings. ▪ Other than the existing PVC tubes/pipes on the east and west side of the control structure , which may have been installed by residents to control the fish population in the lake, the weir openings are consistent with the 1989 plans. We recommend the removal of the existing PVC tubes/pipes. ▪ A raised reticuline steel grate sits above the four weirs and is supported in the elevated position by four 9” x 9” concrete supports at each of the four corners of the existing control structure. We recommend removing the four concrete supports and lowering the grate to the top of the current weir openings (elevation 46.00). Considering that the existing grate is 2-inches thick and, due to its size, needs to sit on top of the south and north walls when the supports are removed from the existing drainage structure, the grate elevation of the 82 Deer Run Subdivision | Willow Lake Control Structure March 13, 2025 (Revised April 14, 2025) Page 2 modified structure will be 46.17 (i.e., elevation 46.00 plus 2-inches (0.17-feet) equals 46.17- feet). This allows the high-level overflow elevation to basically remain the same but allows the removal of the maintenance prone PVC tubes, while at the same time accomplishing the goal of preventing fish from leaving the pond. ▪ Regarding the north side of the control structure, we are recommending removal of the wooden flash boards and installing a 3/8-inch fiberglass plate, bolted, and sealed to the existing structure to cover the flash board opening once the boards are removed . The plate would serve to prevent homeowners from altering the discharge conditions and lowering water levels for Willow Lake, and potentially impacting Howell Creek during extreme storm events. The fiberglass plate would be fabricated with a 6-inch diameter orifice that has a flowline elevation 1-foot below the existing elevation of the weirs on the four sides of the current control structure. This orifice would serve to control the lake level at a constant elevation and allow the level of the lake to recover to the elevation of the orifice following rainfall events. If you have any questions, please do not hesitate to contact me directly at 407-992-9160, extension 309, or by e-mail at david@pegasusengineering.net. END OF MEMO 83 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 1 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: February 14, 2025 (Site Inspection #1) Photograph No. 1 Photographer Location: Northeast of Control Structure Direction Photo was taken: Facing southwest Comments: Photograph No. 2 Photographer Location: Northeast of Control Structure Direction Photo was taken: Facing southwest Comments: 84 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 2 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: February 14, 2025 (Site Inspection #1) Photograph No. 3 Photographer Location: East of Control Structure Direction Photo was taken: Facing west Comments: 85 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 1 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: March 6, 2025 (Site Inspection #2) Photograph No. 1 Photographer Location: Northside of Control Structure Direction Photo was taken: N/A Comments: 30-inch weir opening. Photograph No. 2 Photographer Location: Eastside of Control Structure Direction Photo was taken: N/A Comments: 42-inch weir opening. 86 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 2 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: March 6, 2025 (Site Inspection #2) Photograph No. 3 Photographer Location: Westside of Control Structure Direction Photo was taken: N/A Comments: 42-inch weir opening. Photograph No. 4 Photographer Location: Southside of Control Structure Direction Photo was taken: N/A Comments: 37-inch weir opening. 87 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 3 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: March 6, 2025 (Site Inspection #2) Photograph No. 5 Photographer Location: South of Control Structure Direction Photo was taken: Facing north Comments: Photograph No. 6 Photographer Location: East of Control Structure Direction Photo was taken: Facing west Comments: 88 Pegasus Engineering, LLC 301 West State Road 434, Suite 309 Winter Springs, Florida 32708 407-992-9160 Page 4 PROJECT INFORMATION Project Name: Willow Lake Control Structure Location: Deer Run Subdivision | Tuskawilla Community Inspection Date: March 6, 2025 (Site Inspection #2) Photograph No. 7 Photographer Location: Northeast of Control Structure Direction Photo was taken: Facing southwest Comments: 89 LOWER TO ELEVATION 46.17 AFTER REMOVING SUPPORTS LOWER TO ELEVATION 46.17 AFTER REMOVING SUPPORTS REMOVE FOUR SUPPORTS REMOVE FOUR SUPPORTS INSTALL 42" WIDE x 54" HIGH, 3/8" THICK FIBERGLASS PLATE FABRICATE FIBERGLASS PLATE WITH 6" ORIFICE, 12" BELOW TOP OF PLATE AT FL ELEV. 45.00 INSTALL 42" WIDE X 54" HIGH, 3/8" THICK FIBERGLASS PLATE FABRICATE FIBERGLASS PLATE WITH 6" ORIFICE, 12" BELOW TOP OF PLATE AT FL ELEV. 45.00 INSTALL 42" WIDE X 54" HIGH, 3/8" THICK FIBERGLASS PLATE INSTALL 3" x 3" GALVANIZED ANGLE IRON TO PROVIDE SUPPORT FOR BACK OF FIBERGLASS PLATE. SEAL INTERFACE BETWEEN FRONT OF FIBERGLASS PLATE AND CONCRETE 47.13 47.13 INSTALL 2"x 2"x 48" GALVANIZED ANGLE IRON AT NORTH AND SOUTH ENDS OF STRUCTURE TO PROVIDE SEATS FOR GRATE. BOLT GRATE TO ANGLE IRON TO SECURE GRATE AND PREVENT POTENTIAL MOVEMENT. 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158