CHAPTER 15. UTILITIESCHAPTER 15. UTILITIES\Article 6. Storm Water Utility

The City of Hiawatha, does hereby establish a Storm Water Utility, the purpose of which is to assist the City of Hiawatha in its responsibility for the operation, construction, maintenance and repair of storm water drainage system facilities to provide adequate systems of collection, conveyance, detention, treatment and release of storm water and the reduction of potential hazards to property and life resulting from storm water runoff, improvement in general health and welfare through reduction of undesirable storm water conditions and improvements to the water quality in the storm and surface water system and its receiving waters.

(Ord. 1028; Code 2022)

The City of Hiawatha shall be empowered to administer the Storm Water Utility and may delegate such duty and responsibility as is necessary to carry out the provisions of this article within the limits of the budget, directives and storm drainage regulations adopted by the Governing Body of the City of Hiawatha for this Utility.

(Ord. 1028; Code 2022)

The City of Hiawatha shall adopt an operating budget for each fiscal year. The operating budget shall set forth, for each fiscal year, the estimated revenues and the estimated costs for the storm water utility. The initial operating budget shall be for the fiscal year commencing on January 1, 2010.

(Ord. 1028; Code 2022)

(a)   There is hereby assessed against all property within the City that is connected to either water or sanitary sewer systems, or both, of the City a monthly storm water utility fee. Such fee is based upon a determination of the use for each property. The owner, occupant and any person who is responsible for the payment of water and/or sewer service to the property, shall all be jointly and severally responsible for the payment of said fee. Persons responsible for the payment of water and/or sewer service to the property shall include the person responsible for payment for water provided to a master meter that is then distributed to multiple users, whether or not said users are located on the same property as the master meter. The fee rate schedule shall be:

(1)   All property devoted to a residential use shall be assessed the sum of Four Dollars ($4.00) per month per living unit. The term “residential” shall include single-family homes, mobile homes and mobile home parks, duplexes and apartment units. The term “residential” shall not include rooming or boarding houses, dormitories and similar facilities. The term “living unit” shall mean one or more rooms in a residential building which are arranged, designed, used or intended for use by one (1) family, and which includes cooking space and lawful sanitary facilities reserved for the occupants thereof.

(2)   Property devoted to any use other than residential, as set forth above shall be assessed a monthly fee for Eight Dollars ($8.00) per water meter.

(Ord. 1028; Code 2022)

(a)   Bills shall be rendered monthly as provided in section 15-222 of municipal code of the City of Hiawatha, Kansas, and shall be collected as a combined utility bill.

(b)   Any person at the time of beginning or terminating service who receives service for a period of less than 17 consecutive days shall be billed at no less than one-half of the regular monthly rate. For service of 17 consecutive days or more the charge shall be not less than full regular monthly rate.

(Ord. 1028; Code 2022)

In the event any person, except the United States and the state of Kansas or any political subdivision thereof, shall fail to pay the user charges when due, water service shall be terminated as provided in sections 15-102 to 104 of Municipal Code of the City of Hiawatha, Kansas.

(Ord. 1028; Code 2022)

(a)   Introduction. The Storm Water Management Criteria contained in this plan sets forth the minimum technical criteria for the analysis and design of Storm Water Detention Facilities in Hiawatha, Kansas. The purpose and intent of these criteria are to provide for the proper design of storm water appurtenances and to enhance the harmonious development of the City.

(b)   Applicability. These criteria are applicable to all residential, commercial and industrial development. Storm Water Detention Facilities shall be required where hydraulic calculations indicate an increase in storm water runoff due to proposed development.

(c)   Determining the Need for Detention

(1)   An engineering study as outlined in section 6 of these criteria will be required for all locations to determine the impact of the proposed development on the existing drainage system and the need for detention. The study shall be submitted to the City with the preliminary plat or site plan for proposed development. The City encourages as few detention facilities as possible in order to meet the requirements of this article. The study shall be prepared under the direct supervision of a professionally licensed engineer.

Exceptions Requiring an Engineering Study but no Detention

(2)   Detention will not be required when the engineering study indicates that construction of a detention facility will increase the downstream system’s peak discharge by delaying the peak from the proposed development so that it coincides with the peak discharge from the upstream area.

(3)   Detention will not be required where site discharge occurs within the limits of the 100-year floodplain as defined by the Federal Insurance Study current at the time the development is proposed.

(4)   Requirements may be waived if the drainage study, provided by the Developer and prepared by a registered professional engineer, quantifies the problems and adequately demonstrates to the City that a waiver of a specific requirement is appropriate.

Exceptions NOT Requiring an Engineering Study or Detention

(5)   Detention will not be required for additions to, improvement and repair of existing residential housing up to and including four-plex multi-family dwellings.

(6)   Detention will not be required for residential, commercial or industrial developments of one acre or less and this one-time allowance may not be applied to multi-phase development.

(7)   Detention will not be required for modifications to sites that result in an increase of less than 20% in impervious area. This one-time allowance may not be applied to multi-phase development.

(d)   Hydrological Criteria and Methods. This section sets forth the hydrological method and general parameters to be used for computations of storm water runoff and peak rates for storm water detention.

(e)   Hydrograph Method. The application of a hydrograph method is required for all detention facilities. Computer models or manual methods are permissible as approved by the City. The following is a list of preferred acceptable computer models:

(1)   SCS Technical Release No. 55 (TR-55) – “Urban Hydrology for Small Watersheds”

(2)   SCS Technical Release No. 20 – “Project Formulation – Hydrology”

(3)   US Army Corps of Engineers, Hydrologic Engineering Center – “Hec-1 Flood Hydrograph Package”

(4)   US Environmental Protection Agency “Storm Water Management Model” (SWMM)

(5)   Calculations generated in accredited engineering software programs utilizing one or a combination of the above methods will be accepted.

(f)   Design Storm. The following is a general guide to be used to determine the appropriate design storm for a given watershed:

Tc (minutes)

Time Step (minutes)

Storm Duration (hours)

1 to 12

1

3

12 to 18

2

6

18 to 24

3

12

24 to 30

4

12

>30

5

24

Type II

(g)   Runoff Coefficients. Storm water runoff coefficients or curve numbers shall be determined for proposed land use in modeling. Standard coefficients from an accredited engineering publication will be accepted for use in analysis. Existing runoff coefficients shall be determined but in no case shall existing unpaved areas be analyzed with a curve number exceeding 69 and 79 for Hydrologic Soil Groups B and C, respectively.

(h)   Time of Concentration. The time in concentration shall be calculated as the sum of overland flow time, the shallow concentrated flow time and the concentrated system flow time. Accredited engineering guides utilized shall be provided for support of analysis.

(i)    Easements. In all new developments, developers shall dedicate (plat) easements for all drainage system components. In all existing developments, easements shall be acquired from the property owners at no cost to the City before drainage system improvements are made.

(j)    Maintenance Responsibility. The City shall be responsible for maintenance of enclosed drainage system components within public street rights-of-way only. Maintenance of all improved or natural channels, all overflow channels, detention facilities and enclosed drainage system components within public easements and all easements associated with drainage system components shall be responsibility of the individual property owner or development association.

The City will conduct periodic inspections of above systems. In the event that maintenance concerns are identified but left unresolved by the responsible property owner or association, the City shall resolve those concerns and seek compensation from the responsible property owner or association by assessing cost of maintenance to the responsible properties by certifying the cost of maintenance to the county appraiser to be placed upon the real estate taxes.

(k)   Storm Water Detention Facility Requirements

(1)   Public and private detention facilities shall be sized to provide for no increase in runoff for the proposed development conditions. Proposed detention shall provide control of increased runoff for the 10 and 100-year frequency storms.

(2)   Public and private detention may be accomplished with either wet or dry bottom basin facilities. Public safety shall be addressed in the study if joint uses, such as parking or recreation, are proposed.

(3)   Wet bottom basins shall require additional storage volume to accommodate 5 years of sediment and storage volume necessary to maintain a minimum water depth of 3 feet.

(4)   Erosion control into and out of the proposed detention facilities shall be addressed in the study and provided as necessary.

(l)    Drainage Study Requirements. Storm water drainage studies shall contain the following general information, supporting calculations and drainage map.

(m)  Required Report Content

(1)   Names and addresses of the development team including but not limited to the landowner, developer, architect, and engineer.

(2)   Date of submittal.

(3)   A list of all permits required by local, state and federal agencies.

(4)   General summary discussion regarding the proposed development land use and facilities proposed for storm water management.

(5)   General discussion regarding the impact of the proposed storm water flow to adjacent properties.

(6)   Any special consideration items addressed in the study.

(7)   Supporting calculations and design guides utilized in analysis.

(n)   Drainage Plan Contents

(1)   A contour map indicating on and off site drainage areas to the development used in analysis.

(2)   Proposed location and type of detention facility to be provided.

(3)   Proposed size and type of control structure.

(4)   Existing and proposed 10 and 100-year discharge rates.

(Ord. 1063; Code 2022)