Retention basins, such as this giant one at Elm Court, can also be converted to excellent habitat. Mowing is done annually rather than every week or two, saving money, effort, and any risk associated with mowing those steep slopes. This is just one of many such basins around town, designed to catch runoff from nearby buildings and parking lots. Their periodic inundation would be beneficial to the many kinds of native floodplain wildflowers available.
One basin that has particularly great potential is just down from the office complex on Ewing Street. With the Princeton Charter School next door, it would make a great educational asset for the school if planted with native floodplain species. My efforts to interest the out-of-state owner in substituting habitat for turf were unsuccessful, but it was worth a try.