Projects / Surface Water Management
ABC Flaghole WRP Enhancement Project
The Natural Resources Conservation Services (NRCS-Gainesville) of the United States Department of Agriculture (USDA) requested a comprehensive hydrologic-hydraulic analysis update of a previously completed wetland restoration plan and engineering design for the ABC Flaghole property in Hendry County, FL. The objective was to address issues with proper functioning of the water control structures and ditch blocks throughout the site as well as to configure the design and installation of new structures.
- CLIENT
- USDA, NRCS(sub-consultant to The Trust for Tomorrow)
- YEAR
- 2022-2023
- APPLIED SKILLS
- 2D H&H Modeling
Scenario Evaluation
Cost Estimations - CONSULTING AREAS
- Surface water management
Wetland conservation and restoration - SOFTWARE
- ICPR, ArcMap.
Specifics
Lago developed a new existing conditions ICPR model for the easement area. Information from previous projects and model files, enhanced by newer field and hydrologic data were used to build a 1D network. The new model utilized the 2D overland and groundwater components in ICPR.
The new existing condition ICPR model served as the basis to conduct the scenario evaluations to resolve the issues at existing structures and ditch blocks. A modified wetland restoration plan with replacement of ditch blocks by ditch crossings using operable metal risers or concrete box culverts was proposed. New control elevations were selected similar or slightly above the existing conditions.
Scenario simulations were conducted for the 3-day 25-year design storm to assess potential offsite impacts, and also for a continuous one-year period to assess the surface and groundwater levels for wetland functions. Stage and flow hydrographs were extracted and compared at hydraulic structures. Water table level maps for the dry and wet season were generated, as well as water depth and hydroperiod maps. Difference maps (i.e., scenario – existing conditions) were also produced.
The model results indicated that the proposed improvements would enhance the restoration of the wetland areas in the ABC Flaghole easement without causing potential offsite impacts.