Projects / Groundwater Assessments
Seepage Study beneath and around a pump station
Terracon contracted LAGO to provide MODFLOW modeling support of the seepage beneath and around the pump station presented below. The goal is to determine groundwater heads during construction at maximum gradients, when the water level at the C-51 reservoir is at -20 ft NAVD88 and outside is around 16.5 ft NGVD88.
- CLIENT
- Terracon
- YEAR
- 2023
- APPLIED SKILLS
- Groundwater Modeling
Scenario evaluations - CONSULTING AREAS
- Groundwater seepage
- SOFTWARE
- ArcMap, ICPR, LAGO ToolBox.
Specifics
A steady-state MODFLOW model was developed to estimate the seepage at the structure during construction. Information about the water levels at the canal segments, the geological model and the groundwater parameters (such as hydraulic conductivities Kh and Kv for each geological layer) were provided by Terracon. The model grid had high spatial resolution (i.e., small grid cells) at the structure. Areas with water ponded inside canals and reservoirs are used to define head boundary conditions (BCs).
Groundwater heads & flows were obtained from the model. Head tables/maps at selected planes (as indicated by Terracon) were generated. The total seepage flows around and beneath the pump were computed from the model results. The model was modified to reflect post construction conditions and groundwater heads and flows were obtained.
Outcome
The estimated groundwater heads from the models were provided to the client in the form of contour lines at selected depths, and in form of tables at profiles located at selected locations.