§ 3.10. Stormwater Collection and Conveyance Systems.

a.

System Design Requirements. Drainage improvements shall accommodate runoff from the upstream drainage area in its anticipated maximum "build-out" condition, and shall be designed to prevent overloading the capacity of the downstream drainage system. The City may require the phasing of development, the use of control methods such as retention or detention, or the construction of off-site drainage improvements in order to mitigate the impact of the proposed development. No stormwater collection system shall be constructed unless it is designed in accordance with the City's TCSS Manual by a licensed professional engineer, and unless it is reviewed and approved by the City Engineer. All plans submitted to the City Engineer for approval shall include a layout of the drainage system together with supporting calculations for the design of the system.

b.

All erosion and sedimentation controls shall conform to the TCSS Manual. For erosion and sedimentation control, the City uses the latest edition of "Storm Water Quality Best Management Practices for Construction Activities in North Central Texas" (by the NCTCOG), a copy of which is on file at the City.

c.

No person, individual, partnership, firm or corporation shall deepen, widen, fill, reclaim, reroute or change the course or location of any existing ditch, channel, stream or drainageway without first obtaining written permission of the City Engineer and any other applicable agency (such as FEMA or the U.S. Army Corps of Engineers) having jurisdiction. The City Engineer may, at his or her discretion, require preparation and submission of a CLOMAR or flood study for a proposed development if there are concerns regarding storm drainage on the subject property or upstream or downstream from the subject property. The costs of such study, if required, shall be borne by the developer.

d.

In order to help reduce storm water runoff, and resulting erosion, sedimentation and conveyance of nonpoint source pollutants, the layout of the street network, lots and building sites shall, to the greatest extent possible, be sited and aligned along natural contour lines, and shall minimize the amount of cut and fill on slopes in order to minimize the amount of land area that is disturbed during construction.

e.

No cross-street flow (i.e., perpendicular to traffic flow) of stormwater runoff shall be permitted unless approved by the City Engineer. When and if such drainage flow is allowed, it must be across a concrete street (i.e., valley gutter) and as approved by the City Engineer.

g.

All stormwater retention or detention facilities which are not located underground shall be designed using materials and techniques as established in the City's TCSS Manual or as may be required by the City Engineer.

h.

Funding and priority for stormwater improvements either in existing developed areas of the city or in conjunction with new development may be provided through developer's agreements, TIF funding, Stormwater Utility Fund, CIP or other funding mechanisms as approved by the City Council or other boards and commissions.