April 5, 2023 Update
- Superior Construction completed the Big Sand Lake Drawdown Project today when the lake level reached 93.0’ NAVD88. The pumps were operated beginning January 9 through April 5, 2023, lowering the lake level a total of 3.65’ in 13 weeks.
- Peak stage following Hurricane Ian was 97.03' NAVD88. Pumping operations began when the lake level was 96.65’ NAVD88.
- SFWMD Water Use Permit 48-02756-W authorized pumping until the lake level receded to 93.0’ NAVD88. Pumping operations ceased on April 5, 2023 when the lake level reached 93.0’ NAVD88.
As a result of Hurricane Ian and Tropical Storm Nicole, water levels in Big Sand Lake rose more than 30 inches. On November 16, 2022, the BSLAB unanimously passed a resolution to expend funds for 8 weeks of pumping when the lake receded to 96 feet NAVD88 and before conflicting with the Florida Department of Transportation's (FDOT) outfall lowering project that will lower the outfall from 95.34' to 92.83'.
On November 17, Orange County awarded a contract for pumping services to Superior Construction, the same contractor hired by FDOT to lower Big Sand Lake's outfall.
To allow Superior Construction and County staff to accurately measure water levels prior to and during pumping, Environmental Protection Division staff recalibrated the real-time water level monitoring buoy NAVD88 on November 29, 2022, and Orange County Public Works' Survey Section fabricated and installed a water level staff gauge at the project location on November 30, 2022. (While every effort is made to provide accurate real-time data, the data should not be used without first understanding the limitations. Real-time data is 'as is' without warranty of any kind.)
On December 8, 2022, the Big Sand Lake Advisory Board (BSLAB) approved changes to the lake pumping plan. The new plan extended the pumping duration from 8 to up to 16 weeks (as time allows) and raised the maximum water level threshold for pumping to 97 feet NAVD88. The previous threshold was 96 feet. The December 9 water level reading was 96.82' NAVD88.
Change Order #1 was issued on December 9, 2022 to modify the previous water level conditions listed on the Purchase Order (PO). Change Order #2 was issued on February 1, 2023 to increase the PO amount for additional weeks of pumping. The new total cost of the construction phase of the project is $1,049,637. The new contract amount required approval by the Board of County Commissioners for a budget transfer from reserves.
Final regulatory authorizations for pumping were obtained from the South Florida Water Management District on December 16, 2022 and the Florida Department of Environmental Protection on December 20, 2022.
Superior Construction secured the pumps and began preparing the site on December 21, 2022. After placing the plugs in the outfall pipes, the lake's head pressure began eroding the pipe structure. Due to the infrastructure failure, Superior Construction received approval to modify the plans by constructing an earthen dam downstream from the pipes and shifting the riprap slightly downstream.