Water Service - Water Resources

Villages Development Groundwater Model for a Consumptive-use Permit Renewal

Client:

The Villages Community Development
Location:

Central, Florida
Budget:

$100,000
Key Feature:

Calibration of transient groundwater flow model.

A dynamic MODFLOW model was developed and applied to support an application for renewal of a Consumptive-Use Permit for The Villages Community Development in Central Florida. The model was developed, in part, using an existing regional steady-state MODFLOW model that was developed by the Southwest Florida Water Management District. In addition to moving from steady-state to dynamic operation, model grid resolution was increased in the vicinity of the community’s well fields and site-specific recharge was estimated independently of MODFLOW using a spreadsheet water-balance approach. As well, interactive MODLFOW utilities were developed that included contouring routines and linkages to site basemaps.

 

Model runs were completed to demonstrate that the new MODFLOW model generated results that were consistent with the District’s regional model, and District approval was obtained.

 

 

 

The water balance approach to estimation of net recharge provided an opportunity to reliably account for all sources and sinks at the surface. Although MODFLOW includes reasonable evapotranspiration and recharge utilities, in some cases they fail to adequately address surface hydrology and overall water balance. Using a separate spreadsheet, net recharge for each MODFLOW model cell was estimated as a function of land-use, precipitation, directly connected imperviousness, site-specific irrigation, lake area, and so forth. This water balance approach provided a more realistic assessment of surface hydrology and, once linked to MODFLOW, yielded defensible estimates of groundwater impacts.


The final modelling report is presently under review by the District.