Wastewater Modeling, Scottsdale AZ

As part of the City of Scottsdale’s broader water optimization program, the city turned to GHD to update its wastewater model. The objective was to reflect recent billing data and flow metering results as well as updated development plans and capital improvement projects.

GHD has a long history with the city, having designed more than 50 water projects within the region.

The wastewater model utilizes dry and wet weather steady-state and extended period scenarios to identify current and future capacity challenges within the system. GHD’s hydraulic analysis is focused on the city’s wastewater collection system, consisting of 342 miles (550 km) of sewer lines that span an area of 184 square miles (477 square meters). The model consists of future flow projections and sewer infrastructure improvements for a “built-out” Scottsdale in 2035.

GHD expanded the model to reflect system improvements that have been constructed since it was last updated and performed quality control reviews and updates throughout its databases. We used an extended-period model (48 hours), rather than capturing snapshots of wastewater flows. We leveraged actual GIS-based customer meter data and captured information from 35 temporary meters within the city to validate the model. The model also accounts for rain-derived infiltration and inflow, which is unusual in a desert climate.

“The wastewater modeling performed by GHD is invaluable, said Scott Anderson, Scottsdale’s Project Manager. “It gives us a vision into the future so we can plan for adequate capacity and avoid potential spills. Overall, it contributes to our broader optimization program, which will deliver savings to the city’s budget and resources.”