County engineers say water model can vet data centers; 40 PSI fire-flow standard drives upgrades

Kerry Williams, the county engineering presenter, told commissioners the county maintains a calibrated hydraulic model that can simulate the impact of large water users on distribution pressure and fire flow. "We can put data centers or whatever and model the system and see what impact they will actually have on the system should we put them in different locations within the county," he said.

Williams emphasized that the model focuses on peak-hour demand plus required fire flow and that the county uses 40 PSI as a minimum pressure standard to maintain fire protection. If model results show insufficient pressure the developer is required to address the deficiency—typically by funding new or upsized mains—rather than the county providing the new infrastructure for free. Staff said developer-funded cost-sharing agreements and bonds are standard practice and that new on-site reuse (graywater) or water hubs can reduce a user's draw on the public system, though reuse may change constituent loading and still falls under IPP rules.

Commissioners asked when modeling is done in the approval process; staff said modeling is triggered during sewer-capacity verification and can be run as soon as the project submits demand data. The committee discussed moving modeling earlier in the land-use review or rezoning process to flag capacity limits sooner for big proposals. Staff agreed to provide options for timing changes if the board requests them.