Evaluating Aquifer Storage and Recovery Joel Stevens December 2, 2003 GIS in Water Resources

What is ASR? Temporary storage of water in an aquifer Used in place of water tanks and reservoirs Water is injected during wet or surplus periods and pumped during dry or peak need periods Animation and drawing courtesy of ASR Systems LLC

Project Goals Original Objective: Use GIS to show the change of the TDS concentration gradient of the injected “bubble” over time or its storage period. Modified Objective: Use GIS to physically represent well locations, injection volumes, and differences in hydrogeologic conditions.

Site Location: North Padre Island Corpus Christi

Well Parameters r = (Q/πbφ)1/2 where: r = radius Q = discharge (-) b = aquifer thickness φ = porosity Assumptions Fluid displacement w/o dispersion Aquifer is homogeneous and isotropic Darcian flow conditions Well 1 Aquifer Thickness = 50 ft Porosity = 40 % Injection Rate = 100 GPM Injection Time period = 10 days Total Injection Volume = 1.44 MG Day Date Injection (ft3) Radius (ft) 1 1/1/2003 19250 17.5 2 1/2/2003 24.8 3 1/3/2003 30.3 4 1/4/2003 35.0 5 1/5/2003 39.1 6 1/6/2003 42.9 7 1/7/2003 46.3 8 1/8/2003 49.5 9 1/9/2003 52.5 10 1/10/2003 55.4

Creating Injection Plumes using Buffer Wizard

The Problem of Scale Using USA size resolution for plumes that are measured in tens of feet Change grid size from 1000 to 10

Combining Plumes in ArcCatalog Build attribute tables from each of the well’s ten buffers or plumes.

Tracking Analyst Animation ArcMap Product Tracking Analyst Animation

Interpolating Volume in ArcScene Animation

Conclusions You can manipulate ArcGIS to graphically illustrate simple groundwater processes. ArcGIS is still not suitable for more complex groundwater modeling.

Special thanks to Gil Strassberg from the Center for Research in Water Resources Questions?