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STORM WATER MANAGEMENT
(A) Purpose. The purpose of this subchapter is to promote, preserve and enhance the natural resources within the city and protect them from adverse effects occasioned by poorly sited development or incompatible activities by regulating land disturbing or development activities that would have an adverse and potentially irreversible impact on water quality and unique and fragile environmentally sensitive land; by minimizing conflicts and encouraging compatibility between land disturbing and development activities and water quality and environmentally sensitive lands; and by requiring detailed review standards and procedures for land disturbing or development activities proposed for such areas, thereby achieving a balance between urban growth and development and protection of water quality and natural areas.
(B) Applicability. Every applicant as defined herein must submit a storm water management plan to the City Administrator or designee. No building permit involving land disturbing activities, including but not limited to construction of new residential and/or commercial structures, and no preliminary plat for the subdivision of land within the city, and no permit to allow land disturbing activities, including but not limited to mining, excavation, filling and grading, shall be issued until approval of the storm water management plan or a waiver of the approval requirement has been obtained in strict conformance with the provisions of this subchapter. The lawn fertilizer regulations provisions of this subchapter apply to all land, public or private, located within the city. The provisions of this subchapter shall apply to all properties within the city for which mining or excavation conditional use permits have been issued; said applicability shall become effective on the next annual review date of a mining or excavation conditional use permit following the effective date of this subchapter.
(C) Exemptions. The provisions of this subchapter do not apply to:
(1) Any part of a subdivision if a plat for the subdivision has been approved by the Council on or before the effective date of this subchapter;
(2) Any land disturbing activity for which plans have been approved by the watershed management organization within 6 months prior to the effective date of this subchapter;
(3) A lot for which a building permit has been approved on or before the effective date of this subchapter;
(4) Installation of fence, sign, telephone, and electric poles and other kinds of posts or poles; or
(5) Emergency work to protect life, limb, or property.
(Ord. 2013-05, passed 5-20-2013)
(A) Application required.
(1) Any person, or political subdivision, undertaking an activity for which a surface water management permit is required due land disturbing or development activities shall first submit to the City of Jordan for review; a surface water management permit application, design data, plans, specifications, and such other information and exhibits as required by these rules.
(2) The City of Jordan requires the submittal of the required stormwater pollution prevention plans (SWPPP) for review and comment for all new developments and redevelopments as early as possible in the sketch plan/concept plan review process prior to the site plan or preliminary plat approval process.
(3) In applying for a surface water management permit, the applicant consents to entry upon the land for field inspections and monitoring, or for performing any work necessary to bring the activity into compliance.
(B) Forms. A surface water management permit application shall be submitted on forms provided by the City of Jordan. Forms are available at the Jordan, City Hall.
(C) Action by the city. The City of Jordan shall approve or deny an application containing all required information, exhibits and fees, in accordance with M.S. § 15.99.
(D) Conditions.
(1) A surface water management permit may be approved subject to reasonable conditions to assure compliance with these rules and other applicable city ordinances, as amended. The conditions may include, but are not be limited to, a requirement that the permittee and property owner, including, if appropriate, any mortgagee, enter into an agreement with, and in a form acceptable to, the city to:
(a) Specify responsibility for the construction and future maintenance of approved surface water management structures,
(b) Document other continuing obligations of the permittee or owner,
(c) Grant reasonable access to the proper authorities for inspection, monitoring and enforcement purposes,
(d) Affirm that the city or other political subdivisions can require or perform necessary repairs or reconstruction of such structures,
(e) Require indemnification of the City of Jordan for claims arising from issuance of the surface water management permit or construction and use of the approved structures, and
(f) Reimburse the reasonable costs incurred to enforce the agreement.
(g) Surface water management permits and agreements shall be recorded at the Scott County Recorder's office to provide notice of the conditions and continuing obligations.
(E) Issuance of surface water management permits. The city shall issue a surface water management permit only after the applicant has satisfied all requirements of these rules and other applicable city ordinance, as amended, paid all required fees, entered into any required agreements, and submitted to the city any required security. When the city issues a surface water management permit where plans are required, the city shall endorse in writing or stamp the plans and specifications as "APPROVED." All activity under the permit shall be done in accordance with the approved plans and specifications, 1 set of which shall be kept on the site of the activity at all times while the authorized work is in progress.
(F) Validity. Issuance of a surface water management permit based on plans, specifications, or other data shall not prevent the city from thereafter requiring the correction of errors in the approved plans, specifications, and data, or from preventing any activity being carried on hereunder in violation of these rules.
(G) Modifications. The permittee shall not modify the approved activity, plans, or specifications on file with the city without the prior written approval of the city.
(H) Inspection and monitoring. After issuance of a surface water management permit, the city may perform such field inspections and monitoring of the approved activity as the city deems necessary to determine compliance with the conditions of the surface water management permit, and the applicable city ordinances, as amended. Any portion of the activity not in compliance shall be promptly corrected by the permittee. The cost to the city for field inspections, monitoring, and any work necessary to bring the activity into compliance including services of consultants, shall be payable by the permittee as provided in § 154.034.
(I) Suspension or revocation. The city may suspend or revoke a surface water management permit issued under these rules wherever the permit is issued in error or on the basis of incorrect information supplied, or in violation of any provision of applicable city ordinance, as amended, or if the preliminary and/or final subdivision plat approval is not consistent with the conditions of the permit.
(J) Certification of completion.
(1) The city shall authorize the release of required securities from a development agreement and/or building permit following city inspection and receipt of written certification from a professional engineer licensed in the State of Minnesota verifying completion of the activity in accordance with the approved plans, specifications, and general conditions of the surface water management permit.
(2) Record plans of final grades, building pads, public infrastructure, and copies of documents, with evidence of recording where appropriate, that establish easements or provide for maintenance of structures shall be filed with the city before completion can be certified and final security is released. All temporary, synthetic, and structural erosion prevention and sediment control best management practices (BMPs), (e.g. silt fence) shall be removed following approval of the certificate of completion before final securities shall be released. No activity may be certified as complete if there are any unpaid fees or other outstanding surface water management permit violations.
(K) Other permits.
(1) The applicant shall secure all environmental permits and approvals required by other governmental entities, and promptly provide the city with copies of such permits and approvals after issuance.
(2) In the event the applicant fails to secure the appropriate permits all related site work shall be suspended. Site work may resume when the permitting agency has reviewed required applications and written permit approval is forwarded to the city.
(L) Administration of rules. The City of Jordan shall have administrative authority over the approved comprehensive surface water management plan and associated rules, and/or ordinances, as amended. At any time within 15 business days after a decision or determination by the city, or its agent, interpreting or applying these rules, the applicant, permittee or any other person or political subdivision with an interest in the decision or determination, may appeal to the Jordan City Council. The Planning Commission, at a regular meeting shall review evidence and provide to the City Council its recommendation regarding the appeal. The City Council then at a regular or special meeting, shall consider and affirm, reverse or remand the decision or determination that is on appeal.
(Ord. 2013-05, passed 5-20-2013)
(A) Purpose. It is the intent of the City of Jordan to protect the water resources by requiring that all land-disturbing activities within the city limits comply with minimum standards for the protection of surface water quality and natural resources preservation.
(B) Regulation.
(1) All land disturbing activities, whether requiring a surface water management permit under §§ 154.331 through 154.341 or otherwise, shall be undertaken in conformance with approved BMPs, as approved by the city, and in compliance with the standards and criteria set forth in City Code Ch. 150 Building Regulations, Ch. 153 Subdivisions and Ch. 154 Zoning, as amended.
(2) No person shall conduct land-disturbing activities without protecting adjacent property and water bodies from erosion, sedimentation, flooding or other damage.
(3) Land disturbing activities shall be planned and conducted to minimize the extent of disturbed area, runoff velocities, erosion potential, and to reduce and delay runoff volumes whenever possible. Erosion and runoff controls, consistent with approved BMPs, shall be properly installed before commencing land disturbing activities, and be sufficient to retain sediment on-site. Erosion and runoff controls shall be regularly inspected and maintained per the city approved stormwater pollution prevention plan (SWPPP) and National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) Construction Stormwater Permit requirements. Temporary and permanent vegetative cover shall be installed and maintained until established over all disturbed site areas per the approved SWPPP if the land disturbing activity ceases or is suspended, and prior to issuance of certificate of completion. Pipe outlets shall be provided with temporary or permanent energy dissipation if connected to surface water.
(4) Land disturbing activities shall be planned and conducted to minimize the extent of disturbed area, runoff velocities, erosion potential, and to reduce and delay runoff volumes whenever possible. Erosion and runoff controls, consistent with approved BMPs, shall be properly installed before commencing land disturbing activities, and be sufficient to retain sediment on-site. Erosion and runoff controls shall be regularly inspected and maintained per the city approved stormwater pollution prevention plan (SWPPP) and National Pollutant Discharge Elimination System/State Disposal System (NPDES/SDS) Construction Stormwater Permit requirements. Temporary and permanent vegetative cover shall be installed and maintained until established over all disturbed site areas per the approved SWPPP if the land disturbing activity ceases or is suspended, and prior to issuance of certificate of completion. Pipe outlets shall be provided with temporary or permanent energy dissipation if connected to surface water.
(5) When possible, existing natural watercourses and vegetated soil surfaces shall be used to convey, store, filter, and retain runoff before discharge into public waters or public or private stormwater conveyance systems.
(6) When possible, runoff from roof gutter systems shall discharge onto lawns or other pervious surfaces to promote infiltration.
(7) Use of fertilizer and pesticides in the Shoreland District shall be done so as to minimize runoff into public waters by the use of earth material, vegetation, or both.
(8) When development density, topographic features, and soil and vegetation conditions are not sufficient to adequately handle runoff using natural features and vegetation, various types of constructed facilities such as diversions, settling basins, skimming devices, dikes, watercourses, and ponds may be used. Preference shall be given to designs using surface drainage, vegetation, and infiltration rather than buried pipes and man-made materials and facilities.
(9) Whenever the city determines that a land disturbing activity has become a hazard to any person, endangers the property of another, adversely affects water quality or any waterbody, increases flooding, or otherwise violates this section or the applicable city ordinance, as amended, the owner of the land upon which the land disturbing activity is located, or other person, or agent in control of such land, upon receipt of written notice from the city, shall, within the time period specified therein repair or eliminate such conditions. The owner of the land upon which a land disturbing activity is located shall be responsible for the cleanup and any and all damages resulting from sediment transported off such land. The city may require the owner to obtain a surface water management permit under §§ 154.331 through 154.341 or the applicable city ordinance, as amended, before undertaking any repairs or restoration. The city reserves the right to complete any work required under this chapter and assess the cost against the property.
(10) No person shall develop, redevelop, or commence land disturbing activities on bluffs located in the Bluff Overlay District without protecting adjacent property and water bodies from erosion, sedimentation, flooding or other damage.
(C) Bluff protection criteria.
(1) Minimum bluff standards. Any land disturbing activity, development, or redevelopment of land in an area that meets the minimum criteria of bluff standards in the comprehensive surface water management plan (CSWMP) shall require a current topographic survey to determine if a bluff is present. At its discretion, the city may waive the topographic survey requirement where a review of the available contour information clearly indicates a bluff is not present. Where bluffs are present the following rules shall apply:
(a) All grading, clear cutting, removal of vegetation and/or other land disturbing activities are prohibited in the bluff impact zone and/of bluff face;
(b) All structures shall be set back a minimum of 50 feet from the top of the bluff on all new lots or parcels created after the date of this section adoption. Agricultural buildings shall be set back a minimum of 30 feet from the top of the bluff;
(c) All individual and community sewage treatment systems (ISTS or CSTS) shall be set back a minimum of 50 feet from the top of the bluff impact zone; and
(d) All stormwater ponds, swales, infiltration basins, or other soil saturation-type features shall be set back a minimum of 50 feet from the top of the bluff impact zone.
(2) Additional limitations imposed by the City of Jordan comprehensive surface water management plan.
(a) To appropriately determine where land disturbing activity, development, or redevelopment of land is allowed and is not allowed the city shall reference/review such sources as: site topographic survey data, Unified Soil Classification System (USCS) Soil Survey, Minnesota Land Cover Classification System (MLCCS), Minnesota County Biological Survey (MCBS), etc. The city shall also review the adopted comprehensive plan to determine which upgradient bluff areas are currently planned for development.
(b) The area shall be deemed suitable for land disturbance if review of the available information does not result in identification of a bluff preservation area where disturbance would be prohibited. The characteristics that may be used to determine the presence of a bluff preservation area may include, but not be limited to: unsuitable topography based on topographic survey, unstable soils based on the USCS Soil Survey, the presence of rare or endangered native plant communities based on the MLCCS, or the presence of rare or threatened biological features based on the MCBS.
(3) Permissible land disturbance on bluffs. For those bluffs not located within a delineated bluff preservation area, grading, clear cutting, removal of vegetation and/or other land disturbing activities may be allowed within the bluff impact zone provided the activity is in compliance with the policies identified in the CSWMP's minimum performance standards.
(4) The minimum SWPPP BMPs shall include rapid site stabilization and slope restoration measures as needed to ensure the proposed activity shall not result in:
(a) Adverse impact to adjacent and/or downstream properties or water bodies,
(b) Unstable slope conditions, and
(c) Degradation of water quality due to erosion, sedimentation, flooding, and other damage as stated in this section.
(5) Preservation of existing hydrology and drainage patterns. Land disturbing activities shall not result in any new surface water discharge points along the bluff.
(6) Protection of bluff face. All activities which would result in disturbances or destabilization of the bluff face are prohibited, except as follows:
(a) Maintenance, repair or replacement of public roads, and utility and drainage systems that exist prior to adoption/creation of the bluff preservation area.
(b) Disturbances that are part of the city approved plan to repair, regrade, or re-slope existing bluff faces that are eroding or unstable as necessary to establish stable slopes and vegetation.
(c) Vertical cuts into the bluff face up to 10 vertical feet, measured from the existing top of the bluff, provided that no stormwater is directed over the bluff face and stormwater runoff, including roof drainage, is collected and conveyed to a stable discharge point.
(d) Plantings that enhance the natural vegetation or the selective clearing of noxious, exotic, or invasive vegetation or the pruning of trees or vegetation that is dead, diseased, or pose similar hazards.
(7) Prohibited land disturbance on bluffs. For those bluffs deemed unsuitable for land disturbance activity and identified as a bluff preservation area at any time during the review process, the following requirements shall apply:
(a) All grading, clear cutting, removal of vegetation and/or similar land disturbing activities are prohibited in the bluff impact zone and/or the bluff face,
(b) All structures shall be set back a minimum of 30 feet beyond the bluff impact zone,
(c) All individual and community sewage treatment systems (ISTS or CSTS) shall be set back a minimum of 50 feet from the bluff impact zone, and
(d) All stormwater ponds, swales, or other soil saturation-type features shall be set back a minimum of 50 feet from the bluff impact zone.
(8) Standards for city-sponsored projects. The city shall demonstrate that any city proposed activity in the bluff does not: 1) impact adjacent properties, 2) result in unstable slope conditions and, 3) result in the degradation of surface water or water bodies from erosion, sedimentation, flooding and other damage as stated in division (B) of this section.
(D) Exceptions.
(a) An extractive use site development and restoration plan is developed, approved by all applicable units of government, and followed throughout the course of the project;
(b) The mining operation is conducted in such a manner as to minimize interference with the surface water drainage outside of the boundaries of the mining operation;
(d) The landowner complies with all other applicable federal, state, and local regulations governing mining.
(3) For the purposes of constructing public improvement projects, land disturbances in the bluff impact zone and bluff face may be permitted providing the applicant demonstrates to the city an appropriate need for these activities to occur and that the applicant develops and follows procedures and sequences to minimize impacts on the bluff area.
(Ord. 2013-05, passed 5-20-2013; Am. Ord. 2022-01, passed 2-28-2022)
(A) Purpose. The City of Jordan requires developments or land disturbing activities to comply with the policies identified in the CSWMP. Activities are required to manage stormwater effectively, either on or off-site. To promote and encourage a reduction in runoff rates, encourage infiltration and promote increased groundwater recharge. Manage stormwater to minimize erosion, with an emphasis on stabilizing flow rates and velocities and prioritizing critical areas based on site characteristics, aesthetic conditions, and existing vegetation. Promote development strategies, land use practices, and surface water management activities that decrease and desynchronize peak runoff rates, lengthen the watershed time of concentration, and raise base flow levels.
(B) Regulation. No person or political subdivision shall commence a land disturbing activity or the development or redevelopment of land, unless specifically exempted by division (C) below, without first developing an approved project-specific SWPPP and obtaining all applicable permits from the city and other governing agencies.
(C) Criteria. Project-specific stormwater management plans shall comply with the following criteria:
(1) A hydrograph method based on sound hydrologic theory and approved by the city shall be used to analyze stormwater runoff for the design and analysis of flows and surface water levels.
(2) Stormwater runoff rates for the proposed activities, development, or redevelopment shall:
(a) Not exceed existing runoff rates for the 2-year, 10-year and 100-year, 24-hour, storm events;
(b) Not accelerate on- or off-site water course erosion, downstream nuisance, flooding or damage as demonstrated by the applicant according to division (C)(3)(d) below; and
(c) Be restricted to less than the existing rates when necessary for the public health, safety, and general welfare of the city.
(3) Runoff rates for the proposed activities in unincorporated areas shall:
(a) Not exceed pre-settlement runoff rates for the 2-year, 10-year, and 100-year, 24-hour storm events for land areas annexed into the city that are currently within unincorporated areas of the Scott WMO (Note: As land is annexed into a city, the land being annexed carries with it the existing condition. Parcels developed after the date of this section within unincorporated areas will be regulated using pre-settlement conditions and this would then become the existing condition for the city once the area is annexed. If agricultural land is annexed, agriculture is the existing condition. If roads or streets are present they are part of the existing condition.)
(b) The following curve numbers shall be used to analyze pre-settlement conditions:
Hydrologic Soil Group | Runoff Curve Number |
A | 30 |
B | 55 |
C | 71 |
D | 77 |
(c) For post-development runoff, drained hydric soils shall be assumed to revert to an undrained condition unless the applicant demonstrates that publicly owned and maintained drainage facilities shall be adequate to maintain the drained condition.
(d) Post-development runoff shall not accelerate on or off-site water course erosion, downstream nuisance, flooding or damage as demonstrated by the applicant according to division (C)(4) below; and
(e) Runoff rates may be restricted to less than the pre-settlement runoff rates when necessary for the public health, safety, and general welfare of the City of Jordan.
(f) In situations where the smallest practical outlet as identified by the city is being used and the site will not meet the 2-year discharge rates as identified in the pre-settlement conditions, the site discharge may exceed the pre-settlement 2-year discharge rate if the volume of the 2-year critical duration event being discharged is less than existing 2-year discharge volume from the site and the assessment required in division (C)(4) below is provided and shows no impacts from the increased discharge rate.
(4) An assessment of the potential for adverse impacts downstream of proposed site improvements, whether on- or off-site, is required except when the proposed activity, development or redevelopment is less than 20 acres and less than 8% of the site is covered by impervious surface, or when the rate control provisions of divisions (C)(2), (3), and (5), as applicable, are met; and the proposed activity, development, or redevelopment does not increase runoff volume for the 2-year, 24-hour, storm event (not including snow melt). To demonstrate that the proposed activity does not accelerate on- or off-site erosion, downstream nuisance, flooding or damage, the applicant shall complete an evaluation downstream to the point where the proposed activity is 10% of the drainage area (e.g. a 10-acre development shall evaluate downstream to the point where the drainage area is 100 acres). The evaluation at a minimum shall consist of and include an assessment of:
(a) Potential impacts to areas surrounding landlocked lakes or ponds, or lakes or ponds with inadequate outlets where flood levels would be increased by added runoff volume;
(b) Water levels in the receiving water bodies resulting from the contributing watershed’s full annual runoff yield during a 100-year wet year using the simplified hydrologic yield method (SHYM), or other approved methods for back-to-back 100-year, 24-hour storm events, for both existing conditions and fully developed watershed conditions; and
(c) The identification of public and private structures (including low floor and entry elevations of residences, and ISTS), and infrastructure (sanitary sewer, stormwater pipes and facilities, and roads) surrounding the receiving water bodies and located within 2 vertical feet of the future conditions water level elevation predicted using the SHYM, or the elevation for the back-to-back 100-year, 24-hour storm event.
(5) If there are public or private structures or infrastructure located within 2 vertical feet of the future conditions SHYM, or back-to-back 100-year, 24-hour storm event elevation, the applicant shall either demonstrate that no adverse impacts to health, safety, welfare, or property damage, would occur; or shall provide corrective actions. Corrective actions shall include the following as necessary to mitigate in proportion to the proposed project impact:
(a) Controlling post-development runoff volumes at existing conditions;
(b) Controlling runoff rates to less than existing conditions;
(c) Protecting or re-locating impacted structures or infrastructure, or securing easements for additional flooded areas; or
(d) Other approved actions necessary to mitigate the impact.
(6) Potential impacts. In the event impacts to public or private structures, downstream infrastructure, and erosion along the drainage path or in downstream public waters are identified, an evaluation shall be required. Evaluations shall include:
(a) The identification of existing public and private drainage easements;
(b) The locations, condition, and dimensions of the existing drainage infrastructure to the nearest regional stormwater facility;
(c) The location and elevation of structures with low floors, or entries within 2 vertical feet of the 100-year flood level;
(d) The location and description of known existing flooding problems;
(e) A hydrologic and hydraulic assessment of flooding impacts of the proposed project on downstream public and private structures;
(f) An assessment of existing and potential watercourse erosion, bank stability, bank protection, and watercourse slope;
(g) An assessment of the hydrologic and hydraulic capacity of the downstream public and private infrastructure;
(h) An assessment of property damages including health, safety, and welfare impacts relative to increased flooding of public and private infrastructure. Minnesota Department of Transportation guidelines shall be used to assess safety of flood levels at downstream driveways and road crossings.
(7) Identified property damage. In the event property damage, erosion, public health, safety, and welfare impacts are identified, the applicant shall provide approved corrective action. Corrective actions shall include the following as necessary to mitigate in proportion to the proposed project impact:
(b) Obtaining easements;
(c) The installation of stream bank stability and protection measures;
(d) The upgrading, protecting, or re-locating impacted infrastructure; or
(e) Other approved actions necessary to mitigate the impact.
(8) Wetlands. Evaluate potential impacts to wetlands with exceptional vegetative diversity or functional value (see § 154.337 for determination of exceptional value wetlands). Evaluations shall include:
(b) A hydrologic and hydraulic analysis of the before and after project water level bounce and period of inundation for wetlands with exceptional vegetative diversity for the 1-year, 2-year and 10-year, 24-hour storm events.
(c) The applicant shall provide corrective actions that mitigate in proportion to the proposed project impacts as specified in this rule; if the water level bounce and period of inundation created by the storms evaluated in this section exceeds the limit specified in Table (9)(a).
(d) Corrective actions shall consist of runoff rate and volume controls necessary to keep the water level bounce and period of inundation within the limits specified in Table (9)(a).
(9) All storm drainage conveyance systems shall have capacity for the runoff from a 10-year, 24-hour, storm event. All storm drainage ponds and related facilities shall be designed to store the runoff from the 100-year, 24-hour, storm event or accumulative antecedent conditions without damage to the system or facility, downstream areas and/or significant risk to public health, safety, and welfare unless waived in accordance with this section.
(a)
Hydroperiod standard | Highly susceptible wetlands* | Moderately susceptible wetlands* | Slightly susceptible wetlands* | Least-susceptible wetlands* |
Storm bounce 1 and 2-year events | Existing | Existing plus 0.5 feet | Existing plus 1.0 feet | No limit |
Period of inundation for 1 and 2-year events | Existing | Existing plus 1 day | Existing plus 2 days | Existing plus 7 days |
Period of inundation for 10-year event | Existing | Existing plus 7 days | Existing plus 14 days | Existing plus 21 days |
*See definitions | ||||
(b) Regional detention basins shall be utilized to manage peak flow rates and runoff volumes, and meet water quality objectives when required by the city. On-site stormwater detention basins, volume control facilities, and permanent sedimentation and water quality ponds shall be utilized for land disturbing activities, the development or redevelopment of land that creates greater than 1 acre of impervious surface when regional basins are not in place or feasible, or would not otherwise meet requirements for the protection of downstream areas according to §§ 154.331 through 154.341 that are located between the project and the regional basin.
(c) The city may approve alternative BMPs instead of permanent sedimentation and water quality ponds if it finds that the water quality performance of the proposed alternative BMPs is equivalent to that of a permanent sedimentation and water quality pond designed according to the criteria set forth for permanent sedimentation and water quality ponds in division (C)(11) below. The generally accepted performance of permanent sedimentation and water quality ponds designed to these criteria is 80% total suspended solids removal on an annual average basis. The assumed performance for the proposed BMPs shall be based on information from independent laboratory work, studies, or reference materials including the Minnesota Urban Small Sites BMP Manual (Metropolitan Council 2001), as such manual may be amended, revised, or supplemented. The city may require monitoring of alternative practices and contingency plans similar to the requirements for the general permit authorization to discharge stormwater associated with construction activity under the NPDES/SDS permit program permit MN RI 00001 (NPDES/SDS general construction permit) issued by the Minnesota Pollution Control Agency, August 1, 2003, as amended.
(d) Analysis of flood levels, storage volumes, and flow rates for downstream water bodies and detention basins shall be based on the range of rainfall and snow melt durations producing the critical flood levels and discharges.
(10) Landlocked water basins may be provided with outlets if an outcome based analysis and resource oriented management review regarding downstream impacts is completed that demonstrates:
(b) Dead storage is provided to retain the fully developed future conditions SHYM predicted water volumes, or the back to back 100-year, 24-hour storm event volume, above the highest anticipated groundwater elevation to the extent possible while preventing damage to property adjacent to the basin;
(c) The outlet does not create adverse downstream flooding or water quality conditions, or materially affect stability of downstream watercourses according to the criteria in division (C)(4) of this section;
(d) Proposed development tributary to the land-locked basin has incorporated runoff volume control practices to the extent practical;
(e) There is a demonstrated need for an outlet to protect existing structures and infrastructure; and
(f) The outlet design is part of an approved project-specific SWPPP.
(11) Detention ponds and other permanent stormwater quality management basins shall be designed to provide:
(b) An identified overflow spillway and downstream route sufficiently stabilized to convey the 100-year, 24-hour storm event;
(c) A normal water elevation above the ordinary high water (OHW) of adjacent water bodies or normal water level (NWL) where an OHW is not established; and
(d) Ten-foot wide vehicular access road to the outlet control structure for future maintenance.
(12) Permanent stormwater quality management must be provided in accordance with the NPDES general construction permit no: MN RI 00001 (as amended).
(13) Any new residential, commercial, industrial, and other habitable structures shall be constructed with the following minimum low floor elevations:
(a) Where the 100-year flood level has been established, low floor elevations shall be at least 1 foot above the 100-year flood level. Where the HWL of an adjacent basin has been established, low floor elevations shall be at least 1 foot above the HWL. Elevation of the lowest opening of a structure shall be a minimum of 1 foot above the emergency overflow elevation, or 2 feet above the HWL of the adjacent pond or waterbody, whichever is higher.
(b) For public waters and public water wetlands (DNR protected water bodies) where the 100-year flood level has not been established, low floor elevations shall be at least 3 feet above the ordinary high water level (OHW).
(c) The city shall require a minimum of 3 feet of freeboard above the 100-year back to back 24-hour rainfall event elevation for landlocked basins or ponds where emergency overflows cannot be provided.
(d) In all other cases, the low floor elevation shall be at least 3 feet above the highest known water level.
(e) The lowest exposed floor or opening elevation of structures that are adjacent to ponds shall be indicated on the site grading plan to ensure adequate freeboard. All new structures must have a certificate of survey supplied by the applicant for the city that clearly identifies the as-built low floor elevation and lowest opening elevations. Low floor elevations and lowest opening elevations must comply with the approved development plans, where applicable.
(14) Exhibits. The following represents the City of Jordan stormwater management project submittal checklist. The following exhibits shall accompany the project review application.
(a) Property lines and delineation of lands under ownership of the applicant.
(b) Existing and proposed site contour elevations at a minimum of 2-foot intervals.
(c) Delineation of the subwatershed contributing runoff from any/all off-site sources. Proposed and existing subwatersheds on-site. Emergency overflows and watercourses.
(d) Proposed and existing stormwater facilities location, alignment, and elevation.
(e) Delineation of existing on-site wetland, marsh, shoreland, and floodplain areas.
(f) For applications proposing infiltration as volume control; the identification, description, permeability, hydrologic soil group (HSG) classification and approximate delineation of site soils in both existing and proposed post-development conditions.
(g) The existing and proposed OHW and 100-year high water elevations on-site.
(h) Construction plans and specifications for all proposed stormwater management facilities, including design details for outlet controls.
(i) Stormwater runoff volume and rate analysis for the 2-year, 10-year, and 100-year, 24-hour storm events for existing and proposed conditions.
(j) All hydrologic, water quality, and hydraulic computations made in designing the proposed stormwater management facilities.
(k) Narrative addressing incorporation of infiltration BMP’s.
(l) Delineation of all ponding flowage, drainage easement, or other property interest to be determined for stormwater management purposes.
(15) Maintenance. All stormwater management structures and facilities shall be maintained in perpetuity to assure that the structures and facilities function as originally designed. The responsibility for maintenance shall be assumed either by the City of Jordan, or by the applicant entering into a compliance agreement with the city.
(16) Easements. The applicant shall establish, in a form acceptable to the city, dedicated easements and/or outlets, for ponding, flowage, and drainage purposes over hydrologic features such as water bodies and stormwater basins. The outlets and/or easements shall include the right of ingress and egress for inspection, monitoring, maintenance, and enforcement purposes.
(17) Outlots. The City of Jordan may require that the land be placed in an outlet or a conservation easement, in form acceptable to the city, to prevent the future expansion of impervious surface and the loss of infiltration capacity.
(18) Exceptions. No surface water management permit or stormwater management plan shall be required under this rule for the following land disturbing activities:
(a) Minor land disturbing activities such as home gardens, repairs, and maintenance work, including reseeding or sodding as necessary.
(b) Construction, installation and maintenance of ISTS other than those on steep slopes, on riparian lots within a Shoreland District or in a bluff impact zone.
(c) Construction, installation and maintenance of public utility lines or individual service connections unless the activity disturbs more than 1 acre, in which event division (G)(4) of this section below shall apply.
(d) A land disturbing activity that does not cause off-site erosion, sedimentation, flooding, or other hazards or damage, and disturbs:
1. In the Shoreland District, an area less than 10,000 square feet or less than 100 linear feet of shoreline; in conformance with the City of Jordan Shoreland subchapter for requiring erosion prevention and sediment control BMPs with building permits in a manner consistent with this rule and applicable city ordinances, as amended; or
2. Outside of the Shoreland District, an area of less than 1 acre in conformance with the City of Jordan Subdivision Ordinance for requiring erosion prevention and sediment control BMPs with building permits in a manner consistent with this rule and applicable city ordinances, as amended.
(e) Construction of any structure or associated land disturbing activity on an individual parcel in a subdivision with a stormwater management plan approved by the city, so long as any land disturbing activity complies with the approved plan.
(f) Development or redevelopment of, or construction of a structure on, an individual parcel with a land disturbing activity that does not cause off-site erosion, sedimentation, flooding, or other damage.
(g) Installation of any fence, sign, telephone, or electric poles, or other kinds of posts or poles.
(h) Emergency activity necessary to protect life or prevent substantial harm to persons or property.
(i) Redevelopment projects are exempt from criteria in divisions (C)(2) and (12) of this section. Note: For the purposes of this rule if an activity creates more than 1-acre of new or additional impervious surface the activity is considered new development and the exception shall not apply.
(k) Minor wetland impacts that have received a "Certificate of Exemption or No Loss Determination" by the City of Jordan in the capacity of administering the Wetland Conservation Act, as amended.
(l) All maintenance, repair, resurfacing, and reconditioning activities of existing roads, bridges, and highway systems which do not involve land disturbing activities outside of the existing surfaced roadway.
(m) Land disturbing activities associated with the construction of conservation practices by the SWCD or the Natural Resources Conservation Service (NRCS) provided that erosion prevention and sediment control practices are used in a manner consistent with this rule and applicable city ordinances, as amended.
(Ord. 2013-05, passed 5-20-2013; Am. Ord. 2022-01, passed 2-28-2022)
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