Changes to Neff's Creek floodplain.
Flood Control Engineering
As used in this chapter:
"Governmental entity" means the state and its political subdivisions.
"Political subdivisions" means any county, city, town, school district, public transit district, redevelopment agency, special improvement or taxing district, or any other political subdivision or public corporation.
"State of Utah" means the state of Utah or any office, department, agency, authority, commission, board, institution, hospital, college, university or other instrumentality thereof. (Ord. 827 §§ 2, 1982: Ord. 817 §§ 2 (part), 1982: prior code §§ 7-2-1 (part))
It is unlawful for any person, firm, corporation or governmental entity to interfere with, cause damage to, destroy or use for any purposes any flood control, storm drainage, water quality control, or water conservation structure, facility, appurtenance, or any other property owned, constructed, maintained or controlled by or on behalf of the county, as identified in Section 17.08.040 of this chapter, without having first received a written permit from the division.
The division may impose such terms and conditions as may be necessary to provide for the carrying away and the safe disposal of natural stormwaters and floodwaters, and to prevent the destruction or obstruction of any such structure, facility, appurtenance, etc., and to insure the proper maintenance and restoration of any such structure, facility, appurtenance or property. Application for use of such structures, facilities, appurtenances or property shall be made to the director of the division and shall set forth the particular use desired and the purpose and duration of use.
Permits shall be revocable when, in the discretion of the director of the division, the public interest and welfare so requires. (Ord. 817 §§ 2 (part), 1982: prior code §§ 7-2-1 (part))
No permit shall be required for any existing use of natural channels within the county for such beneficial purposes as are approved by the Office of the State Engineer for the state; nor shall it affect any water rights established by the State Engineer or by any court of competent jurisdiction.
No provision contained in this title shall be construed to interfere with or permit the regulation, allocation or reallocation of water rights or water right use or of any culinary water collection or distribution system or waters and facilities used in connection therewith. (Ord. 817 §§ 2 (part), 1982: prior code §§ 7-2-6)
All plans for public and private development that will alter the natural flow of surfacewater upon the lands involved in the development shall be submitted to the division for review and approval prior to the commencement of work thereon. Plans for a development which will drain into a flood control or storm drainage facility maintained by a city shall be the responsibility of that city and submission of the plans to the division shall not be required. The city shall review such plans to assure compliance with those provisions of Section 17.08.020 applicable to city facilities which connect to those facilities identified in Section 17.08.040 of this chapter.
The division may require the design of erosion and sediment control or other measures to protect the capacity of any flood control or storm drainage facilities or the quality of the water flowing through any part of the flood control and storm drainage system as defined in Section 17.08.040. "Water quality" or "quality of water," whenever used in this section, refers to and incorporates those definitions and standards which are set forth in the county''s then-current water quality management plan, as established by the division. (Ord. 817 §§ 2 (part), 1982: prior code §§ 7-2-3)
A. Replacement and new bridges or culverts on the natural tributaries and open man-made channels, except irrigation canals, listed in Section 17.08.040, shall be sized for a frequency based on consideration of the benefits and costs derived from the improvements.
As a minimum all such bridges and culverts shall be designed to pass the greater of the one-hundred-year snowmelt runoff or the twenty-five-year cloudburst storm unless the director of the division of flood control and water quality shall deem such level of protection unwarranted. In any case, replacement culverts or bridges with an equivalent opening of sixty inches in diameter, or greater, shall be sized for at least the one-hundred-year snowmelt or twenty-five year cloudburst standard.
Bridges and culverts on Big and Little Cottonwood Creeks through the valley floor shall be designed for the greater of the one-hundred-year snowmelt or the one-hundred-year cloudburst storm for present development conditions. In addition to the design flow, consideration shall be given to the freeboard necessary to pass debris and accommodate bed load and bulking.
B. The phrase ""one-hundred-year snowmelt"" means that snowmelt runoff of the magnitude which is expected to occur on the average of a one-hundred-year frequency or has a one-percent chance of being equalled or exceeded during any one year.
C. The phrase ""twenty-five-year cloudburst storm"" means that cloudburst storm of the magnitude which is expected to occur on the average of a twenty-five-year frequency or has a four-percent chance of being equalled or exceeded during any one year. (Ord. 921 §§ 1, 1985: prior code §§ 7-2-9)
It is unlawful for any person, firm or corporation, or governmental entity to place or cause to be placed in the channel or drain or within or upon any flood control channel, reservoir, detention basin, debris basin, spreading ground or other property over which the county has an interest, matter of any kind that may operate to impede, retard or change the normal direction of the flow of floodwaters, stormwaters, or other waters, or that may catch or collect debris carried by such waters, or that may be carried downstream by such waters to the damage and detriment of adjacent private or public property, or that may degrade the quality of the water, without first obtaining a written permit for such placement from the director of the division. (Ord. 827 §§ 3, 1982: Ord. 817 §§ 2 (part), 1982: prior code §§ 7-2-4)