Polluted storm water runoff is often transported to storm drain systems, referred to by the permit as, municipal separate storm sewer systems (MS4s) and ultimately discharged into local rivers and  streams without treatment.  EPA’s Storm Water Phase II Rule establishes an MS4 storm water management program that is intended to improve the Nation’s waterways by reducing pollutants that drain into storm drain systems during storm events and non-stormwater runoff.  Common pollutants include oil and grease, salts and deicing materials associated with transportation.  Pesticides, fertilizers and organic refuse from private and commercial landscape maintenance.  Sediment and various construction related pollutants from construction sites projects.  Also carelessly discarded trash and poor trash receptacle management, mostly paper and plastic.  When these pollutants are collected by the miles of roadway gutter and acres urban surfaces, the volumes are significant and impair the waterways, negatively affecting the beneficial use of the water body, contaminating water supplies,  habitat for aquatic organisms, and land wildlife. 

In 1990, EPA promulgated rules establishing Phase I of the National Pollutant Discharge Elimination System (NPDES) storm water program.   The Phase I program for MS4s requires operators of “medium” and “large” MS4s, that is, those that generally serve populations of 100,000 or greater, implement a storm water management program as a means to control polluted discharges from these MS4s.  The Storm Water Phase II Rule extends requirement of the NPDES storm water program to certain “small” MS4s.

General Information
The Riverton City Storm Drain System, also referred to as the stormwater system, maintenance and UPDES Management falls under the Public Works Department.   Development oversite  and management falls under Development Services.  The Public Works Director can be contacted at the following address and phone number:

Public Works Director
12526 S 4150 W
Riverton, Utah 84065

Some general information for Riverton City follows:




12 Square Miles

Geographic Description:

Southwest area of Salt Lake  Valley

Receiving Waters:

Jordan River, Midas, Rose and Butterfield Creeks,

Beckstead Ditch and the South Jordan, Utah and Salt Lake, and Utah Lake Distributing Canals

Annual Precipitation:


Type of Community:



40 31’04”N


111 56’21.30”W


The Riverton City Stormwater System consist of various types, including but not limited to: high-back, mountable and ribbon curb, rural dirt shoulder, pipe, manholes, catch basins, detention and retention, drywells, swales, ditches, streams, rivers and canals.  The City has 3 high level Low Impact Development sites but most of the City consist of traditional roadway gutter and detention type flood control systems.  New development consist of more of a traditional regulation retention system and traditional flood control systems for the excess.

See Link to Stormwater System Inventory

Riverton City Drainage Way History
Two primary creek systems cross Riverton City flowing west to the east.   The third Butterfield system is diverted to Midas creek in Herriman City but still exists in Riverton downstream of Redwood Road.  Rose Creek is located at the southern boundary and Midas Creek on the northern boundary.  Butterfield Creek was historically located more-less through the center.  The Historic Butterfield Creek split somewhere around 4000 West but only remnants remain beginning at Redwood Road at 11850 South on the north and 13500 South on the south end of the City.   Previously Butterfield Creek discharged over the surface into downstream canal systems.  In addition, farming practices slowly filled Butterfield Creek with soil causing Butterfield Creek to shrink and later residential development ultimately erased its existence across most of the City except for the eastern quarter.   Riverton is divided by five canals which flow from the south to the north.  Beginning on the east boundary is the Beckstead Ditch, South Jordan Canal, Utah and Salt Lake Distributing, Utah Lake Distributing respectively and the furthest west is the Welby Canal, also know as the Provo River or Highland Canal. 

Development accelerated in the 1990’s and continues rapidly today.  Like many cities in the Jordan Valley Riverton  was changing from a rural community to an urban city.  Early development occurred with little or no runoff volume management.  Many flood control systems were surface in nature, were shared with gravity irrigations and piped drainage systems were less common.  The primary drainage ways receiving the new urban developments runoff impact were the five canals and Rose and Midas Creeks.  However, by the mid 1990's it was recognized modern flood control management was becoming necessary.  

Some of todays challenges come from the fact that many subdivisions did not have their own detention systems and many piped systems were installed through private property.  Also, the canals and creeks received much of this new runoff impact without runoff rate restriction using most of the receiving systems capacity, leaving new development with significant discharge rate restrictions.   Also Rose and Midas Creeks and the canals had to pick up the load from the abandoned Butterfield Creek basin resulting in expensive piped systems for conveying the basin runoff to Rose Creek, Midas Creeks, the Jordan River and the canals where possible.  Runoff to canals resulted in the necessity for overflow structures for spilling excess runoff volume from the canals to the creeks.

In 2002 UDOT improved 12600 South which included a conveyance system from the west side of the City to the Jordan River, however, betterment cost prohibited including much of the already built out Butterfield Basin which resulted in a 12600 South system basin which is mainly limited to the 12600 South frontage properties only.

Local Water Quality Concerns
Phase 1 of the Jordan River Total Maximum Daily Load(TMDL) Water Quality Study identifies organic material as the primary pollutant which is depleting to much oxygen in the river.  Although pollution constituent levels vary along the river segments, and are all important to manage, but organic matter seems to be the common pollution constituent of concern; see sections 2.7.2, 2.73, 5.3.3 of TMDL Study.  Other pollutants of concern are TDS, E.coli  and even temperature but segment 6 of the river where Riverton is located, temperatures are to high and organic material contributions throughout the entire reach of the river are swept downstream causing problems by overloading the lower segments with organic material. 
By observation the primary pollution material in Riverton loose organic material collecting in storm drain catchment systems mostly residential and commercial fallen tree and shrubbery leaves, urban transportation system sediments,  and unintended pollution from property maintenance, and construction activities.  Property maintenance operations usually result in grass clippings and fertilizers in the roadways exposed to storm drains but also loose trash either intentionally discarded or more commonly trash unintentionally blowing from poorly managed trash receptacles and dumpsters.  Construction related pollutants are primarily sediments and, fugitive dust and trash.  Construction is regulated by a permit system with a control system in place to manage construction sources, where as, educational programs are much more practical for non permitted residential  and commercial property maintenance activities.
The retention regulation should limit and is expected to effectively manage solid type pollutants like organics but water soluble pollutants are a concern with the current type of retention infrastructure most preferred by development.  The preferred retention infrastructure are underground galleries and siphon type water quality devices which will likely not protect groundwater resources from common water soluble pollutants.  Development and local elected officials are currently not supporting surface low impact development approaches and filters effective for water soluble pollutants are to expensive.  In addition, Riverton is more than 75% built out with mostly existing traditional flood control infrastructure and the remaining land is not developing with true surface low impact development or cartridge type filter system expected to be most effective for managing water soluble pollutants. 

Commercial, Institutional, Industrial,  and private owners association properties developed after 2010 are managed by permit regulated Long-Term Stormwater Management Plans and Agreement however there are currently not enough employees to effectively manage private implementation of Long-Term Stormwater Management regulation.

Permit Requirements
The permit requirements are found in the Permit for Jordan Valley Municipalities UTS000001.  For your convenience the requirement summary is provided. 

The Stormwater Management Program must, reduce the discharge of pollutants to the “maximum extent practicable” (MEP), protect water quality and intending to satisfy the water quality requirements of the Clean Water Act.

Storm water management programs must include, six minimum control measures(MCM).  Each MCM requires multiple programs demonstrating the whole of the MCM is adequately managed;

  1. Public Education and Outreach
  2. Public Participation/Involvement
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Storm Water Runoff Control
  5. Long-Term Storm Water Management in New Development and Redevelopment Control
  6. Pollution Prevention and Good Housekeeping for Municipal Operations

MCMs must also specifically incorporate controls to reduce and manage urban nitrogen and phosphorus impacts. 

Measurable goals and interim milestones for the development of each program and a measure of success for the implemented programs, i.e. observation, numeric water quality measurement or other adequate means necessary to determine program effectiveness.

Permits expire and must be renewed in addition to any renewal permit requirements.  The current permit expires February 25, 2025.

The permit requires an annual assessment of SWMP program implementation and  Minimum Control Measure(MCM) program successes.  The assessment is expected to be included in the SWMP document.
Individual MCM programs include a measure of success, see programs 1-6
TABLE A references MCM programs to the corresponding regulation.

An annual report submitted on a DEQ standard form including certification of compliance is required October 1st annually.  Permit Regulation 2.1.5, 4.5, 5.6

The SWMP must be  accessible to the public.  SWMP supplementary records must be kept for at least 5 years.  

SWMP amendments are allowed upon notification and approval by the DEQ.  An amendment request must include an written justification, including but not limited to: performance, infeasibility, application, assessments, non-applicability, changes of conditions and so forth.  Amendments may also be required but DEQ audits. 

The NPDES permit is State and federally enforceable, thus subjecting the City to potential enforcement actions and penalties by the NPDES permitting authority for non-compliance.  This federal enforceability also includes the right for interested parties to sue under citizen suit provision (section 405) of CWA.


Stormwater Utility Budget
The permit requires the City to secure the resources necessary to meet all requirements and to conduct an annual analysis of the human resource, capital and operations and maintenance expenditures defined in Section of the Jordan Valley Municipalities (MS4) Permit; No. UTS000001

The permit requires the City to secure the resources necessary to meet all requirements and to conduct an annual analysis of the human resource, capital improvements and operation expenditures.  The funding details are elaborated in the Stormwater Utility Budget section.

Funding Sources
1. Stormwater User Fee
2. Sales Tax


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