(a) Stormwater management facilities may include structural and non-structural practices. Natural swales and other natural runoff conduits shall be retained where practicable.
(b) Where additional stormwater management facilities are required to satisfy the minimum control requirements, the following measures are examples of what may be used in their order of preference:
(1) Low impact development (LID) practices, such as minimizing the area of streets, parking lots and rooftops; bio-retention swales and basins; porous pavement; or other innovative measures to reduce runoff volume and protect water quality;
(2) Facilities designed to encourage overland flow, slow velocities of flow, and flow through buffer zones;
(3) Regional stormwater detention structures (dry basins);
(4) Regional stormwater retention structures (wet basins);
(5) On-site stormwater detention structures (dry basins);
(6) On-site stormwater retention structures (wet basins); and
(7) Infiltration practices, where permeable soils are present.
(c) Where detention and retention structures are used, designs which consolidate these facilities into a limited number of large structures are preferred over designs which utilize a large number of small structures, unless LID features are used to provide post construction water quality.
(d) C-SWPPPs can be rejected by the Director if they incorporate structures and facilities which have the potential to result in significant long-term maintenance problems. The structure design parameters outlined in the Design Manual must be met to prevent being rejected.
(e) The drainage system and all stormwater management structures within the County (including both public and private portions) will be designed to the same engineering and technical criteria and standards. The Land Development Division’s review will be the same whether the portion of the drainage system will be under public or private control or ownership.
(f) All stormwater management measures shall be designed in accordance with the design criteria contained in the Stormwater Management Design Manual using procedures contained in this manual or procedures approved by the Director.
(1976 Code, § 8-81) (Ord. 3551, passed 11-11-2001; Ord. 4281, passed 5-5-2009; Ord. 4698, passed 5-5-2015)