According to Wikipedia, Pavement milling (cold planning, asphalt milling, or profiling) is the process of removing at least part of the surface of a paved area such as a road, bridge, or parking lot. Milling removes anywhere from just enough thickness to level and smooth the surface to a full depth removal.
Detention pond compliance is based on 100-year storm routing, not storage volume alone. Per the City of Dallas Storm Drainage Design Manual, routing analysis must confirm that peak discharge and maximum water surface elevation remain within allowable limits and do not encroach into required freeboard. Excess storage volume does not eliminate the need to demonstrate proper outlet performance.
According to the City of Dallas Storm Drainage Design Manual, detention ponds are required to maintain a minimum of 2.0 feet of freeboard above the design water surface elevation to provide a safety buffer against overtopping, outlet blockage, and storm events exceeding the design criteria.
Freeboard must be verified through stage–storage analysis, not assumed. A detention pond that meets the required storage volume but does not maintain the minimum freeboard is considered noncompliant and may increase the risk of embankment failure and downstream impacts.