Volume 2-05, Chapter 3 - City of Wichita

Section 3.1 - Stormwater Management Controls Overview
Backyard
Grass Channel
Roadside Grass
Channel
Direction
of flow
100-year
detention
Permanent
Pool
Figure 3-7 Example Treatment Train – Rural Residential Subdivision
(Adapted from: NIPC, 2000)
A gas station and convenience store is depicted in Figure 3-8. In this case, the decision was
made to intercept hydrocarbons and oils using a commercial gravity (oil-water) separator
located on the site prior to draining to a sand filter for removal of finer particles and TSS. No
stormwater control for channel protection is required as the system drains to the municipal
storm drain pipe system. Flood control is provided by a regional stormwater control
downstream.
Figure 3-9 shows an example treatment train for a commercial shopping center. In this case,
runoff from rooftops and parking lots drains to depressed parking lot islands, perimeter grass
channels, and bioretention areas. Slotted curbs are used at the entrances to these swales to
better distribute the flow and to settle out the very coarse particles at the parking lot edge for
sweepers to remove. Runoff is then conveyed to an extended detention wet pond for
additional pollutant removal and channel protection. Flood control is provided through parking
lot detention. (The acceptability of parking lot detention will be determined by the local
reviewing authority on a case-by-case basis.)
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Volume 2, Technical Guidance