For a developer, it was as good as things can get.

Officials with Reliable Contracting had all their permits in hand to lay pipes and install a giant stormwater pond at the Preserve at Severn Run, a 72-home development in the works in Millersville.

And then they threw them out.

At the nudging of environmentalists and the county’s top public works official, Reliable started all over, and designed a system that will more naturally move stormwater off-site.

And if all goes according to plan, the system will reduce pollution and preserve the health of a rare trout stream nearby, the Jabez Branch.

The redoing and...