To facilitate settlement of a water rights dispute among three municipal entities, LRE used an existing groundwater model developed by one of the entity’s consultant to estimate the maximum yield each entity could pump without causing excessive drawdown in each well and without causing exclusive drawdown in “trigger monitoring wells” installed during settlement of a prior dispute between two of the parties.
- The pumping optimization considered each entity’s desired well field yield, maximum allowable drawdown and a range of well efficiencies.
- The optimization was conducted using the existing MODFLOW model coupled with the model-independent optimization code PEST.
- The difficulty of the optimization problem in this case necessitated running PEST in parallel mode and custom codes were developed to speed up the optimization by leveraging the power of cloud-computing.
- Water quality concerns from municipal entities, including our client, were addressed using the particle-tracking code MODPATH. The particle-tracking results were used to approximate the origin and travel path to each municipal well.
- These results showed acceptable travel times and travel paths to each municipal well. The optimization modeling effort resulted in a three-way stipulated settlement agreement that avoided years of costly litigation.