Chapter 13.25


13.25.010    Purpose.

13.25.020    Definitions.

13.25.030    Stormwater utility created.

13.25.040    Maintenance of city storm sewer facilities and assets.

13.25.050    Utility administration.

13.25.060    Service charge imposed.

13.25.070    System of rates and charges.

13.25.080    Billing and collection.

13.25.090    Appeal of charges.

13.25.100    Annual report to stormwater utility customers.

13.25.010 Purpose.

The city finds and declares that absent effective maintenance, operation, regulation and control existing stormwater drainage conditions in all areas within the city constitute a potential hazard to the health, safety and general welfare of the city. The city council further finds that natural and manmade storm sewer facilities and conveyances constitute a storm sewer system and that effective improvement, regulation, and control of stormwater through formation by the city of a stormwater utility requires the transfer to the utility of all storm sewer facilities and conveyances and related rights belonging to the city. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-010.]

13.25.020 Definitions.

For the purpose of this chapter, the following definitions shall apply. Words used in the singular shall include the plural, and the plural shall include the singular; words used in the present tense shall include the future tense. The word “shall” is mandatory and not discretionary. The word “may” is permissive. Words not defined in this section shall be construed to have the meaning given by common and ordinary use as defined in the latest edition of Webster’s Dictionary.

“BMP” means best management practices to improve stormwater quality as defined in Riverton City’s “Guidance Document for Stormwater Management.”

“City” means Riverton City, a municipal corporation of the state of Utah.

“City engineer” means the Riverton City engineer or engineer’s designee.

“Council” means Riverton City council.

“County” means Salt Lake County.

“Customer” or “person” means any individual; public or private corporation and its officers; partnership; association; firm; trustee; executor of an estate; the state or its departments, institutions, bureaus, or agencies; county; city; political subdivision; or any other governmental or legal entity recognized by law.

“Developed parcel” means any parcel whose surface has been altered by grading, filling, or construction of any improvement.

“Equivalent residential unit (ERU)” means a unit equal to the square footage of impervious surface area. This is based on an average single-family residential parcel, which has an impervious surface area of 2,744 square feet.

“Guidance Document for Stormwater Management” means Salt Lake County Public Works Department “Guidance Document for Stormwater Management.”

“Impervious surface” means a parcel’s hard surface area that causes water to run off its surface in quantities or speeds greater than under natural conditions and discharge directly into the city’s storm sewer system. Some examples of impervious surfaces are rooftops, concrete or asphalt paving, walkways, patios, driveways, parking lots or storage areas, and gravel that has been subject to surface traffic, including compacted gravel surfaces.

“Mitigation” means on-site facilities or practices which reduce stormwater quantity or improve stormwater quality.

“National Pollutant Discharge Elimination System (NPDES) Stormwater Regulations” means the provisions of the Federal Clean Water Act establishing specific permit requirements for the control of stormwater discharge.

“Parcel” means the smallest, separately segregated unit of land having an owner. A parcel has boundaries and surface area, and is documented with a property number by the county.

“Single-family residential parcel” means any parcel of land containing a single-family dwelling unit.

“Storm sewer drainage system” means all manmade storm sewer facilities and conveyances, and natural stormwater systems owned or maintained by the city that store, control, treat, and/or convey stormwater.

“Storm sewer facilities” means any facility, improvement, development, or property made for controlling stormwater quantity and quality.

“Stormwater” means water produced by storms, surface drainage, snow and ice melt, and other water handled by the storm sewer drainage system.

“Stormwater Design Standards Manual” means Riverton City Stormwater Design Standards Manual maintained by the engineering division and approved by the city engineer.

“Stormwater utility” or “utility” means the utility created by this chapter, which operates, maintains, regulates, and improves storm sewer facilities and programs within Riverton City.

“Undeveloped parcel” means any parcel that has not been altered by grading, filling, or construction. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-020.]

13.25.030 Stormwater utility created.

There is hereby created and established a stormwater utility and service charge rate structure. The utility will have regulatory authority and responsibility for planning, design, construction, maintenance, administration and operation of all city storm sewer conveyances and facilities. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-030.]

13.25.040 Maintenance of city storm sewer facilities and assets.

The utility shall operate, maintain, and improve all existing city storm drainage facilities used for the conveyance of stormwaters, through, under or over lands or watercourses, beginning at a point where the stormwaters first enter the storm sewer system of the city and ending in each instance at a point where the stormwaters exit from the system. Stormwater facilities do not include government-owned streets or those storm sewer facilities operated and maintained by, or for, the county or the state of Utah. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-040.]

13.25.050 Utility administration.

The storm sewer utility shall be administered by the city engineer. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-050.]

13.25.060 Service charge imposed.

All persons otherwise responsible for impervious surfaces within the city which contribute runoff to the stormwater system or who otherwise use or benefit from the stormwater utility of the city will be responsible for paying the stormwater utility fees as set forth in the Riverton City fee schedule; provided, however, service charges may be reduced up to 45 percent for impervious surface areas which are:

(1) Distant from the storm drainage system, such that the possibility of a future connection to the system is remote; and

(2) Isolated from other impervious areas; and

(3) Adjacent to an undeveloped area of equal size, owned or controlled by the same property owner, capable of absorbing the runoff from the impervious surfaces. Absorption fields will require a perpetual drainage easement to be recorded with the Salt Lake County recorder’s office. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-060.]

13.25.070 System of rates and charges.

(1) Service Fees Imposed. The city will impose storm sewer drainage fee rates and charges on each parcel of real property within the city except Riverton-owned facilities, public streets and stormwater facilities operated and maintained by or for the stormwater utility, the county or the state of Utah. The charges shall fund the administration, planning, design, construction, water quality programming, operation, maintenance, and repair of existing and future stormwater facilities.

(2) Methods of Determining Contribution of Stormwater.

(a) Contributions of stormwater from nonresidential parcels and residential parcels larger than duplexes have been ascertained through aerial photography and site plans by evaluating land surface and measuring the amount of impervious surface.

(b) Contributions of stormwater from residential parcels have been ascertained by sampling the amount of residential impervious areas with the use of aerial photography, site plans, and GPS (global positioning systems).

(3) Method of Determining Service Fee Rates. Storm drainage service fees shall be assessed on each parcel of real property within the city, except Riverton-owned facilities, public streets and state or county stormwater facilities. Service fees shall be set forth in the Riverton City fee schedule and may be differentiated according to the following classifications:

(a) Residential Parcels. Single-family residential parcels shall constitute one ERU per month. Duplex parcels shall constitute two ERUs per month.

(b) Undeveloped Parcels. Undeveloped parcels shall have no charges assessed.

(c) Other Parcels. Charges for all other parcels shall be computed by multiplying the total ERUs for a parcel by the monthly rate. Total ERUs are calculated by dividing total square feet of impervious surface by 2,744 (one ERU), rounded to the nearest whole number.

(4) Credits and Reduced Fees.

(a) Eligibility. Utility fee credits are available to nonsingle-family residential parcels, which exceed stormwater management requirements for quantity or quality of stormwater runoff as outlined in the “Riverton City Stormwater Design Standards Manual.”

(i) Developments, approved after January 19, 2009, must comply with the requirements of Chapter 13.20 RCC, Stormwater Ordinance. No credit shall be given for meeting these requirements. However, credits may be given for new developments with improvements or implemented BMPs, which exceed stormwater management requirements.

(ii) Developments approved prior to January 19, 2009, may receive credits by reducing the quantity of stormwater runoff, or implementing best management practices (BMPs) to improve storm runoff quality, as described below.

(b) Maximum Possible Credit. An analysis of the utility costs has determined that approximately 45 percent of planned expenditures are variable and directly related to stormwater flows and nonpoint source pollution. Fifty-five percent of the utility’s costs are fixed program expenditures not directly affected by fluctuations in flow or water quality. Nonsingle-family residential parcels may receive utility fee credits of up to 45 percent by (i) constructing or operating on-site facilities which reduce the quantity of stormwater runoff 25 percent, or (ii) implementing or continuing on-site source or treatment controls which improve the quality of the stormwater runoff 20 percent.

(c) Credit for Reducing Quantity of Stormwater Runoff.

(i) Detention. Stormwater detention facilities hold runoff for a period of time and release it at a controlled rate to the storm drainage system. Utility fee credits may be given to parcel owners who install facilities to detain storm runoff to a discharge rate lower than that specified in the “Riverton City Stormwater Design Standards Manual” in cubic feet per second per acre (cfs)/acre. The amount of credit is proportional to the discharge rate, based on the following formula:

Percent of Fee Credit = 25 [(D-q) / D]


25 = Percentage representing costs for utility’s improvement program.

D = Maximum allowable stormwater discharge rate from a parcel in cubic feet per second per acre (cfs/acre).

q = Peak stormwater discharge rate from a parcel in cfs/acre.

(ii) Retention. Retention facilities hold water until it evaporates or infiltrates into the ground. On parcels where the city engineer determines retention is required, the maximum credit for reducing stormwater runoff and improving water quality is 45 percent.

(d) Credit for Improving Stormwater Quality. Nonsingle-family developments may qualify for stormwater quality credit by implementing source or treatment controls, which exceed stormwater management requirements in force at the time of development approval. These source or treatment controls are known as best management practices (BMPs) applicable in whole or in part to specific types of businesses or land uses. The guidelines for BMPs within Riverton City are identified in the “Stormwater Design Standards Manual.” The amount of the quality credit may be up to 20 percent of the total fee based on:

(i) The number of best management practices which are directly applicable to the property; and

(ii) The number of those applicable best management practices that the property owner has implemented on the site and which have been approved by the city engineer. This credit will be based on the value assigned to the implemented BMPs by the city engineer or a designee during a review of the credit application.

(iii) Credit for Regional Stormwater Quantity Mitigation. Nonresidential parcels with stormwater facilities, that serve the city’s regional stormwater needs, as prescribed by the city engineer, and utilize methods that meet the city’s design and maintenance standards, may be eligible for a utility fee credit. The credit may be granted, if property owners have not already been compensated for constructing and maintaining such facilities, through impact fee offsets or reimbursements. Fee reduction will be determined by the city engineer based on prorated share of nondevelopment benefit.

(iv) Credit Requests. The owner of a parcel, or agent, must make application for utility fee credit to the city engineer. If a request for mitigation credit is granted, the credit shall be applied to all charges from the time of the appealed billing, and will be reflected on the next billing.

(v) Low Income Relief. A single-family residential parcel owner who qualifies for the city’s low income relief, as determined by the city council and set forth by established city policy for low income relief, may also be eligible for a reduction in the service charge for their parcel. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-070.]

13.25.080 Billing and collection.

(1) Utility Enterprise Fund. This chapter creates the stormwater utility fund. All revenues received from storm drainage user fees shall be placed in the enterprise fund as a designated fund, to be left separate and apart from all other city funds. The collection, accounting, and expenditure of all stormwater utility funds shall be in accordance with the Utah Uniform Fiscal Procedures Act.

(2) Billing. The city shall bill, or cause to be billed, property owners for stormwater drainage utility services. Fees and charges shall be considered delinquent if not paid as determined by the procedures established by the city and will be a debt to the city, which shall be subject to recovery in a civil action. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-080.]

13.25.090 Appeal of charges.

Any nonresidential customer who disagrees with the storm drainage user fee for his or her parcel may apply to the city engineer for a user fee adjustment. The adjustment request must state the grounds for adjustment and must be filed in writing with the city engineer no later than 30 days after receipt of billing. The city engineer shall review the request and basis for user charges to determine whether an error was made in the calculation or application of the fee. The city engineer may approve an adjustment to the fee.

An appeal of a city engineer’s decision may be brought before the city manager within 30 days after the date of the city engineer’s decision. The decision of the city manager shall be final and conclusive.

If an appeal of charges is successful, credit will be applied to all charges from the time of the appealed billing, and will be reflected on a future billing after the appeal is granted. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-090.]

13.25.100 Annual report to stormwater utility customers.

The city’s stormwater utility, acting through the citizen’s stormwater management advisory committee, shall cause to be completed an annual report on the stormwater utility which, if accepted, shall be presented for approval by the city council. This report shall summarize the financial activities of the utility and the major areas of expenditure, field activities, accomplishments, and the upcoming year’s priorities. [Ord. 10-08 § 1 (Exh. A). Code 1997 § 14-5-100.]