AN ORDINANCE TO CREATE CHAPTER [NUMBER] OF THE [CODE OR ORDINANCE] OF THE [NAME OF MUNICIPALITY] RELATING TO THE CONTROL OF POST-CONSTRUCTION RUNOFF
FOREWORD.
The intent of this ordinance is to reduce the discharge of pollutants carried in storm water runoff to waters of the state. Use of this ordinance by municipalities will foster the consistent, statewide application of post-construction performance standards for new development and redevelopment contained in subch. III and IV of ch. NR 151, Wis. Adm. Code. The [governing body (town board of supervisors, county board of supervisors, city council, village board of trustees, or village council)] of the [name of municipality] does hereby ordain that Chapter [number] of the [code or ordinance] of the [name of municipality] is created to read as follows:
[CHAPTER]
POST-CONSTRUCTION STORM WATER MANAGEMENT
S. 01 AUTHORITY.
(1) This ordinance is adopted by the [governing body] under the authority granted by s. [59.693 (for counties); 60.627 (for towns); 61.354 (for villages); or 62.234 (for cities)], Wis. Stats. This ordinance supersedes all provisions of an ordinance previously enacted under s. [59.69, 60.62, 61.35, or 62.23], Wis. Stats., that relate to storm water management regulations. Except as otherwise specified in s. [59.693, 60.627, 61.354, or 62.234], Wis. Stats., s. [59.69, 60.62, 61.35, or 62.23], Wis. Stats., applies to this ordinance and to any amendments to this ordinance.
Note to Users: There may be instances when this ordinance does not supersede other ordinances relating to construction erosion control previously adopted by the governing body.
(2) The provisions of this ordinance are deemed not to limit any other lawful regulatory powers of the [governing body].
(3) The [governing body] hereby designates the [administering authority] to administer and enforce the provisions of this ordinance.
(4) The requirements of this ordinance do not preempt more stringent storm water management requirements that may be imposed by any of the following:
(a) Wisconsin Department of Natural Resources administrative rules, permits, or approvals including those authorized under ss. 281.16 and 283.33, Wis. Stats. (b) Targeted non-agricultural performance standards promulgated in rules by the Wisconsin Department of Natural Resources under s. NR 151.004, Wis. Adm. Code. S. 02 FINDINGS OF FACT.
The [governing body] acknowledges that uncontrolled, post-construction runoff has a significant impact upon water resources; the health, safety, and general welfare of the community; and diminishes the public enjoyment and use of natural resources. Specifically, uncontrolled post-construction runoff can do all of the following:
(1) Degrade physical stream habitat by increasing stream bank erosion, increasing streambed scour, diminishing groundwater recharge, diminishing stream base flows, and increasing stream temperature.
(2) Diminish the capacity of lakes and streams to support fish, aquatic life, and recreational and water supply uses by increasing pollutant loading of sediment, suspended solids, nutrients, heavy metals, bacteria, pathogens, and other urban pollutants.
(3) Alter wetland communities by changing wetland hydrology and increasing pollutant loads.
(4) Reduce the quality of groundwater by increasing pollutant loading.
(5) Threaten public health, safety, property, and general welfare by overtaxing storm sewers, drainage ways, and other minor drainage facilities.
S. 03 PURPOSE AND INTENT.
(1) PURPOSE. The general purpose of this ordinance is to establish long-term, post-construction runoff management requirements that will diminish the threats to public health, safety, welfare, and the aquatic environment. Specific purposes are to do all of the following:
(a) Further the maintenance of safe and healthful conditions.
(b) Prevent and control the adverse effects of storm water; prevent and control soil erosion; prevent and control water pollution; protect spawning grounds, fish, and aquatic life; control building sites, placement of structures, and land uses; preserve ground cover and scenic beauty; and promote sound economic growth.
(c) Control exceedance of the safe capacity of existing drainage facilities and receiving water bodies; prevent undue channel erosion; and control increases in the scouring and transportation of particulate matter.
(d) Minimize the amount of pollutants discharged from the separate storm sewer to protect the waters of the state.
(2) INTENT. It is the intent of the [governing body] that this ordinance regulates post-construction storm water discharges to waters of the state. This ordinance may be applied on a site-by-site basis. The [governing body] recognizes, however, that the preferred method of achieving the storm water performance standards set forth in this ordinance is through the preparation and implementation of comprehensive, systems-level storm water management plans that cover hydrologic units, such as watersheds, on a municipal and regional scale. Such plans may prescribe regional storm water devices, practices, or systems, any of which may be designed to treat runoff from more than one site prior to discharge to waters of the state. When such plans are in conformance with the performance standards developed under s. 281.16, Wis. Stats., for regional storm water management measures and have been approved by the [governing body], it is the intent of this ordinance that the approved storm water management plan be used to identify post-construction management measures acceptable for the community. S. 04 APPLICABILITY AND JURISDICTION.
(1) APPLICABILITY.
(a) Except as provided under par. (b), this ordinance applies to a post-construction site on which one acre or more of land disturbing construction activity occurs during construction.
Note to Users: The one acre land disturbance threshold is consistent with state and federal laws regarding applicability of construction site erosion and sediment control permits. The municipality may apply its ordinance to sites of less than one acre.
(b) A site that meets any of the criteria in this paragraph is exempt from the requirements of this ordinance:
1. A post-construction site with less than ten percent connected imperviousness, based on the area of land disturbance, provided the cumulative area of all impervious surfaces is less than one acre. However, the exemption of this subdivision does not include exemption from the protective area standard of this ordinance.
2. Agricultural facilities and practices.
3. Underground utility construction, but not including the construction of any above ground structures associated with utility construction.
(c) Notwithstanding the applicability requirements in par. (a), this ordinance applies to post-construction sites of any size that, as determined by the [administering authority], are likely to result in runoff that exceeds the safe capacity of the existing drainage facilities or receiving body of water, causes undue channel erosion, or increases water pollution by scouring or the transportation of particulate matter.
(2) JURISDICTION.
This ordinance applies to [post-construction sites within the boundaries and jurisdiction of the [name of the municipality];
or
post-construction sites within the boundaries and jurisdiction of the [name of municipality], as well as the extraterritorial division of land subject to an ordinance enacted pursuant to s. 236.45 (2) and (3), Wis. Stats.; or
post-construction sites within the boundaries and jurisdiction of the [name of the municipality], as well as all lands located within the extraterritorial plat approval jurisdiction of the [name of municipality], even if plat approval is not involved].
Note to Users: These options differ in the amount of land area covered by this ordinance and may have ramifications for enforcement authority. For counties, the first option will be the only option since counties do not have extraterritorial authority. Under s. 59.693 (10), Wis. Stats., if a county storm water management ordinance exists at the time of annexation, then the municipal ordinance must be at least as restrictive as the county ordinance. (3) EXCLUSIONS.
This ordinance is not applicable to activities conducted by a state agency, as defined under s. 227.01 (1), Wis. Stats. S. 045 SUBDIVISION AND NUMBERING OF THIS ORDINANCE; WORD USAGE
(1) This ordinance is divided into sections designated by boldface numerals and abbreviated “S.”. Sections may be divided into subsections designated by numerals in parentheses and abbreviated “sub.” Subsections may be divided into paragraphs designated by lower case letters in parentheses and abbreviated “(par.).” Paragraphs may be divided into subdivisions designated by numerals followed by a period and abbreviated “subd.” Subdivisions may be further subdivided into paragraphs designated by lower case letters followed by a period and those paragraphs may lowercase Roman numerals, which are abbreviated in the form “subd. 1. a.” and “subd. 1. a. i.,” respectively. Reference to a “section,” “subsection,” “paragraph,” or “subdivision” includes all divisions of the referenced section, subsection, paragraph, or subdivision.
(2) The singular includes the plural, and the plural includes the singular. The present tense of a verb includes the future when applicable. The future perfect tense includes past and future tenses.
S. 05 DEFINITIONS. In this ordinance:
(1) “Adequate sod or self-sustaining vegetative cover” means maintenance of sufficient vegetation types and densities such that the physical integrity of the streambank or lakeshore is preserved. “Self-sustaining vegetative cover” includes grasses, forbs, sedges, and duff layers of fallen leaves and woody debris.
(2) “Administering authority” means a governmental employee, or a regional planning commission empowered under s. [59.693; 60.627; 61.354; or 62.234], Wis. Stats., that is designated by the [governing body] to administer this ordinance.
(3) “Agricultural facilities and practices” has the meaning given in s. 281.16 (1), Wis. Stats. (4) “Atlas 14” means the National Oceanic and Atmospheric Administration (NOAA) Atlas 14 Precipitation-Frequency Atlas of the United States, Volume 8 (Midwestern States), published in 2013.
(5) “Average annual rainfall” means a typical calendar year of precipitation as determined by the Wisconsin Department of Natural Resources for users of models such as WinSLAMM, P8 or equivalent methodology. The average annual rainfall is chosen from a department publication for the location closest to the municipality.
(6) “Best management practice” or “BMP” means structural or non-structural measures, practices, techniques, or devices employed to avoid or minimize sediment or pollutants carried in runoff to waters of the state.
(7) “Business day” means a day the office of the [administering authority] is routinely and customarily open for business.
(8) “Cease and desist order” means a court-issued order to halt land disturbing construction activity that is being conducted without the required permit or in violation of a permit issued by the [administering authority].
(9) “Combined sewer system” means a system for conveying both sanitary sewage and storm water runoff.
(10) “Connected imperviousness” means an impervious surface connected to the waters of the state via a separate storm sewer, an impervious flow path, or a minimally pervious flow path.
(11) “Design storm” means a hypothetical discrete rainstorm characterized by a specific duration, temporal distribution, rainfall intensity, return frequency, and total depth of rainfall.
(12) “Development” means residential, commercial, industrial, or institutional land uses and associated roads.
(13) “Direct conduits to groundwater” means wells, sinkholes, swallets, fractured bedrock at the surface, mine shafts, non-metallic mines, tile inlets discharging to groundwater, quarries, or depressional groundwater recharge areas over shallow fractured bedrock.
(14)* “Division of land” means the creation from one parcel of [number] or more parcels or building sites of [number] or fewer acres each in area when such creation occurs at one time or through the successive partition within a 5-year period.
Note to Users: This definition is only needed depending on the type of jurisdiction selected under S. 04 (2) above.
(15) “Effective infiltration area” means the area of the infiltration system that is used to infiltrate runoff and does not include the area used for site access, berms, or pretreatment.
(16) “Erosion” means the process by which the land’s surface is worn away by the action of wind, water, ice, or gravity.
(17) “Exceptional resource waters” means waters listed in s. NR 102.11, Wis. Adm. Code. (18)* “Extraterritorial” means the unincorporated area within three miles of the corporate limits of a first, second, or third class city, or within one and a half miles of a fourth class city or village.
Note to Users: This definition is only needed depending on the type of jurisdiction selected under S. 04 (2) above.
(19) “Filtering layer” means soil that has at least a 3-foot deep layer with at least 20 percent fines; or at least a 5-foot deep layer with at least 10 percent fines; or an engineered soil with an equivalent level of protection as determined by the regulatory authority for the site.
(20) “Final stabilization” means that all land disturbing construction activities at the construction site have been completed and that a uniform perennial vegetative cover has been established with a density of at least 70 percent of the cover for the unpaved areas and areas not covered by permanent structures or that employ equivalent permanent stabilization measures.
(21) “Financial guarantee” means a performance bond, maintenance bond, surety bond, irrevocable letter of credit, or similar guarantees submitted to the [administering authority] by the responsible party to assure that requirements of the ordinance are carried out in compliance with the storm water management plan.
(22) “Impervious surface” means an area that releases as runoff all or a large portion of the precipitation that falls on it, except for frozen soil. Rooftops, sidewalks, driveways, gravel or paved parking lots and streets are examples of areas that typically are impervious.
(23) “In-fill” means an undeveloped area of land located within an existing urban sewer service area, surrounded by development or development and natural or man-made features where development cannot occur.
(24) “Infiltration” means the entry of precipitation or runoff into or through the soil.
(25) “Infiltration system” means a device or practice such as a basin, trench, rain garden, or swale designed specifically to encourage infiltration, but does not include natural infiltration in pervious surfaces such as lawns, redirecting of rooftop downspouts onto lawns, or minimal infiltration from practices, such as swales or road side channels designed for conveyance and pollutant removal only.
(26) “Land disturbing construction activity” means any man-made alteration of the land surface resulting in a change in the topography or existing vegetative or non-vegetative soil cover that may result in runoff and lead to an increase in soil erosion and movement of sediment into waters of the state. “Land disturbing construction activity” includes clearing and grubbing, demolition, excavating, pit trench dewatering, filling, and grading activities.
(27) “Landowner” means any person holding fee title, an easement, or another interest in property that allows the person to undertake cropping, livestock management, land disturbing construction activity, or maintenance of storm water BMPs on the property.
(28) “Maintenance agreement” means a legal document that provides for long-term maintenance of storm water management practices.
(29) “Maximum extent practicable” means the highest level of performance that is achievable but is not equivalent to a performance standard identified in this ordinance as determined in accordance with S. 055 of this ordinance.
(30) “New development” means development resulting from the conversion of previously undeveloped land or agricultural land uses.
(31) “NRCS MSE3 or MSE4 distribution” means a specific precipitation distribution developed by the United States Department of Agriculture, Natural Resources Conservation Service, using precipitation data from Atlas 14.
(32) “Off-site” means located outside the property boundary described in the permit application.
(33) “On-site” means located within the property boundary described in the permit application.
(34) “Ordinary high-water mark” has the meaning given in s. NR 115.03 (6), Wis. Adm. Code. (35) “Outstanding resource waters” means waters listed in s. NR 102.10, Wis. Adm. Code. (36) “Percent fines” means the percentage of a given sample of soil that passes through a # 200 sieve.
(37) “Performance standard” means a narrative or measurable number specifying the minimum acceptable outcome for a facility or practice.
