Projects / Surface Water Management
I-75 W2 water control structure replacement evaluation
The SFWMD has requested engineering services for the replacement of the I-75-2 water control structure on the I-75 canal in the Big Cypress Basin (BCB). This required the use of the existing MIKE SHE/MIKE11 model to simulate propose a new operational protocol to maximize flood control and pre-storm draw down capabilities and long-term water conservation/dry season water resource benefits.
- CLIENT
- SFWMD(subconsultant to R. J. Behar & Company, Inc.)
- YEAR
- 2023
- APPLIED SKILLS
- Integrated Modeling
Scenario evaluations - CONSULTING AREAS
- Surface water management
- SOFTWARE
- ArcMap, MIKE SHE/MIKE11
Specifics
The current MIKE SHE/MIKE11 model for the BCB area was run in the latest software version to become the baseline existing conditions model. Then, the model was modified to replace the I-75-2 structure according to the design plans, to remove the I-75-1 weir, and to change the GG2 gates control operation.
A total of five alternatives were considered as part of the scenario evaluation. They included using or not a back flow pump with various pump schedules, various dry/wet season rules for the new gates, and variations in the way that the three gates are operated (e.g., opening simultaneously or two gates closed most of the time).
Model results from design storms were extracted to present stage and flow hydrographs, peak stages and flows, and peak stages profiles along the I-75 canal. Results from 1-year simulations were also extracted to show stage and flow hydrographs, water table level hydrographs, and water table level difference maps for each month.
Outcome
The modeling suggested that a backflow pump would be of no use, and that the dry season water levels upstream of I-75-2 could be maximized just by operating the gates optimally. The replacement project together with the proposed gate operations at GG2 and I-75-2 would optimize the flood control functions of the two canals and increase the groundwater levels during the dry season (Oct 15 - May14). The modified operation of the water control structures will not raise the wet season (May 15 - Oct 14) groundwater levels significantly above the existing condition levels.