1,300 Acres of Solar Across Two Counties and a Floodplain

Renewable energy at this scale doesn’t just plug into the grid. It has to work with the land. This 170-megawatt solar energy farm spans 1,300 acres across Pinal and Pima Counties in southern Arizona, incorporating solar panel arrays, battery storage, fire staging areas, and connecting gravel roads. Our team provided comprehensive civil engineering and surveying services from site planning through construction-ready design.

We delivered civil design to support the minor comprehensive plan amendment and rezoning application, a process that required coordination with two separate county jurisdictions. The dual-county setting added complexity to every approval, but it also expanded the project’s reach and impact across a broader region of the state’s growing renewable energy corridor.

Reading the River Before Designing the Site

The Santa Cruz River floodplain runs through the project area, and understanding its behavior was essential before a single panel could be sited. Our stormwater team evaluated hydraulic conditions by analyzing and modifying a regional two-dimensional study of the Santa Cruz River and Tortolita Mountain tributary watershed. That analysis characterized the floodplain and floodway impacts on the site and directly informed preliminary grading and drainage plans for both counties.

It’s the kind of work that never appears on a rendering but determines whether a project this large can be built responsibly. For a 170-megawatt facility contributing to Arizona’s clean energy future, getting the hydrology right was as important as getting the panels in the ground.