Simulation of Water Resources Management in the Pajaro Valley

Science Center Objects

Two key hydrologic issues in all coastal aquifer systems are the delineation and the management of the renewable water resources. The proper development and management of the renewable resources helps to minimize ground-water mining of the lower aquifer systems, and minimizes overdraft and seawater intrusion of the upper aquifer system while maximizing the sustainable yield of the renewable water resources in Pajaro Valley.

Pajaro Valley

Simulation of Water Resources Management in the Pajaro Valley

The sedimentary layering and, in particular extensive fine-grained layers, commonly control the depth of the renewable resource and the depth of penetration of recent recharge. The renewable resources typically occur in the upper aquifers but may include parts of the lower aquifers in the forebay and foothill regions of the aquifer system. The proposed cooperative studies with the U.S. Geological Survey focus on creating an operations-based hydrologic model that allows
Pajaro Valley Water Management Agency (PVWMA) to assess the impact of Basin Management Plan (BMP) actions on the sustainability of the renewable ground-water resources. This will be accomplished in two proposed phases by:

Phase 1:

  1. Develop a conceptual model for the Pajaro Valley,
  2. Converting the existing regional model to MODFLOW-2000 (MF2K),
  3. Upgrading the previous simulations by adding additional simulation features,
  4. Updating the new model through 2005,

Phase 2:

  1. Linking land use with remote-sensing data to help keep the model current and useful to PVWMA staff, and
  2. Develop optimization/management analysis tools that will allow PVWMA staff to assess the performance of current and planned BMP activities.

Thus, phase 1 of the proposed project will develop the conceptual model of ground-water/surface-water flow and then upgrade, update, and recalibrate the regional flow model that can then be used to immediately test the project components that are currently being implemented by PVWMA. Then phase 2 will allow PVWMA to keep the model current with management tools linked to the hydrologic model. This important second phase will allow PVWMA staff to use the model not only for operational assessments of current conditions but also for forecasting near-future (< 2 years ahead) or decadal projections (10 - 50 years) needed to assess the potential impact from policy development or capital improvement projects related to implementation of the BMP.