§ 7-5.602. Standards of construction.

Properties located outside the SFHA are still subject to potential flooding caused by local drainage problems. To ensure that new development is elevated well above the street level or otherwise protected from shallow drainage flooding the following standards are required for all development in all areas of the City:

(a)

These standards shall apply on all development exceeding one-half acre in size, and/or increasing impervious area by over 5,000 square feet.

(b)

The lowest floor elevation of any structures shall be at least one foot above the crown of the nearest street.

(c)

The site plan shall account for street flooding and local drainage from and onto adjoining properties and protects the building from local drainage flows.

(d)

The site plan shall provide positive drainage away from the building site to an approved point of collection that does not create a hazard or problem on neighboring properties.

(e)

All requirements of the most current NPDES stormwater permit shall be enforced including, but not limited to:

(1)

Preference to the use of low-impact development techniques (instead of pipes, channels, or detention) to control the impacts of development on runoff.

(2)

Include in the design of the stormwater management facilities appropriate "best management practices" that will improve the quality of surface water.

(3)

At least once each year, the owners of all stormwater management facilities including, but not limited to, retention basins, detention basins, debris basins and "best management practices:"

(i)

Have the facilities inspected by a licensed professional engineer;

(ii)

Perform any and all necessary maintenance, repair or replacement as recommended by the engineer; and

(iii)

Submit the report to the Floodplain Administrator; and

(iv)

If the owner fails to perform items (i), (ii) or (iii) above, the City shall have the authority to perform the inspection, maintenance repair and/or replacement and receive reimbursement from the owner for the work performed.

(f)

For all new development, the maximum storm water discharge of the ten (10), twenty-five (25), fifty (50) and 100-year storms shall be limited to the pre-developed ten-year (10-year) peak flow rate.

(1)

Before development, the developer must submit hydrologic and hydraulic studies showing the nature and extent of runoff under present conditions and with the proposed development for those four (4) rainfall events. Peak runoff from new development shall be no greater than the runoff from the site in its pre-development condition.

(2)

For projects of less than ten (10) acres, on-site detention in the amount of 1,000 cubic feet per acre of developed area or greater shall be provided.

(3)

For projects of or greater than ten (10) acres, the required detention storage shall be based on a calculated hydrograph for a developed 100-year frequency storm.

(4)

Additional detention may be considered for reduction of the discharge rate commensurate with deficiencies in downstream facilities.

(§ 1 (Exh. A), Ord. No. 1268, eff. April 20, 2017)