(A) Conceptual drainage plan review.
(1) In order to establish that an adequate drainage outlet(s) exists for a proposed development, a developer may apply for a conceptual drainage plan review by the city. Note that any preliminary drainage approval by the city as a result of such a review is based on preliminary data and shall not be construed as a final drainage approval or considered binding on either party.
(2) The following is a general listing of minimum data requirements for the review of conceptual drainage plans:
(a) Complete sets of conceptual plans showing general project layout, including existing and proposed drainage systems and proposed outlets (plan sheets must be larger than 11 inches by 17 inches, but not to exceed 24 inches by 36 inches);
(b) General description of the existing and proposed drainage systems in narrative form;
(c) Watershed boundaries on the city’s one-foot or two-foot topographic mapping;
(d) Existing watercourse or regulated drains; and
(e) Letter of intent for obtaining any needed consents, off-site easements, right-of-way, or regulatory permits.
(B) Permit procedures.
(1) This section applies to all development, or re-development of land, that are subject to this subchapter as specified in § 54.21. Individual lots with a land disturbance of greater than 10,000 square feet and less than one acre must refer to § 54.32(D) for plan review requirements and procedures.
(2) Figure 6-1 is a flowchart summarizing the plan review/permit approval process and can be found in division (K) below. The project site owner shall submit an application for a stormwater management permit to the city. The application will include a draft notice of intent letter (NOI) that would also act as permit application form, construction plan sheets, stormwater drainage technical report, a stormwater pollution prevention plan for construction sites (if the total disturbance is one acre or more), post-construction pollution prevention plan (if the total disturbance is one acre or more), and any other necessary support information. Specific information to be included in the application can be found in division (C) below. Adequate number of copies of each application material, as noted in the “Stormwater Permit Application Check-In Checklist” contained in the city’s Stormwater Technical Standards document, must be submitted to the city. Additionally, a digital copy of the construction plans is required in a format acceptable to the city.
(3) After the city receives of the application, the applicant will be notified as to whether the application was complete or insufficient. The applicant will be asked for additional information if the application is insufficient. The information provided will be reviewed in detail by the city or its plan review consultant(s). Once all comments have been received and the review completed, the city will either approve the project or request modifications.
(4) Once a permit has been issued, the project site owner must file a notice of intent a minimum of 48 hours prior to the commencement of construction activities. Notification shall be in the form of an updated NOI form. The submittal of the NOI must be provided to the city and the IDEM. The IDEM submittal must include a proof of publication, verification that the jurisdictional entity approved the plan, appropriate fee, and any other information required by IDEM. The city submittal must include copies of the final, approved construction plans, stormwater drainage technical report, stormwater pollution prevention plan for construction sites (if the total disturbance is one acre or more), post-construction stormwater pollution prevention plan, the written notification, and proof of publication. The number of required copies varies from case to case and must be determined by contacting the city. A pre-construction meeting is required to be held with the participation of the city and other entities involved prior to any grading activity to ensure that appropriate perimeter control measures have been implemented on the site and the location of any existing tiles has been properly marked.
(5) Once construction starts, the project owner shall monitor construction activities and inspect all stormwater pollution prevention measures in compliance with this subchapter and the terms and conditions of the approved permit. Upon completion of construction activities, as-built plans must be submitted to the city. A notice of termination (NOT) shall be sent to the city once the construction site has been stabilized and all temporary erosion and sediment control measures have been removed. The city, or a representative, shall inspect the construction site to verify the requirements for an NOT have been met. Once the applicant receives a “verified” copy of the NOT, they must forward a copy to IDEM. Permits issues under this scenario will expire three years from the date of issuance. If construction is not completed within three years, the NOI must be resubmitted at least 90 days prior to expiration.
(C) Information requirements: development or redevelopment disturbing or impacting greater than one acre.
(1) Specific projects or activities may be exempt from all or part of the informational requirements listed below. Exemptions are detailed in §§ 54.28 through 54.31. If a project or activity is exempt from any or all requirements of this subchapter, an application must be filed listing the exemption criteria met, in lieu of the information requirements listed below. This level of detailed information is not required from individual lots that disturb or impact less than one acre of land that are developed within a larger permitted project site. Review and acceptance of such lots is covered under § 54.32(D).
(2) The different elements of a permit submittal for a stormwater plan approval include a draft notice of intent (NOI), construction plans, a stormwater drainage technical report, a stormwater pollution prevention plan for active construction sites, a post-construction stormwater pollution prevention plan, and any other necessary supporting information. In addition, an updated NOI along with proof of publication of a public notice will need to be submitted directly to IDEM, with a copy provided to the city after the permit is approved. All plans, reports, calculations, and narratives shall be signed and sealed by a professional engineer or a licensed land surveyor registered in the state.
(a) Draft notice of intent.
1. The NOI is a standard form developed by the State Department of Environmental Management which requires general project information. As part of the city’s stormwater management permit application package, the NOI form must be completed in full based on data and information available at the time of application.
2. An updated version of this form, accompanied by proof of publication in a newspaper of general circulation in the affected area that notified the public that a construction activity is to commence, will need to be resubmitted later after the stormwater management permit is granted and at least 48 hours prior to commencement of construction. The publication must include the following language:
“(Company name, address) is submitting an NOI letter to notify the City of Greenfield and the Indiana Department of Environmental Management of our intent to comply with the requirements of the City of Greenfield Stormwater Management Ordinance, as well as the requirements of 327 IAC 15-2-2 and 327 IAC 15-6, to discharge stormwater from construction activities for the following project: (name of the construction project, address of the location of the construction project, and Parcel Identification Number). Runoff from the project site will discharge to (stream(s) receiving the discharge(s)).”
(b) Construction plans. Construction plan sheets (a minimum of 11 inches by 17 inches, but not to exceed 24 inches by 36 inches in size) with a scale of one inch = 20 feet, 30 feet, 40 feet, 50 feet, or 60 feet and an accompanying narrative report shall describe and depict the existing and proposed conditions. This must be submitted in digital format acceptable to the city as well as hard copy. Note that in order to gain an understanding of and to evaluate the relationship between the proposed improvements for a specific project section/phase and the proposed improvements for an overall multi-section (phased) project, the detailed information requested herein for the first section/phase being permitted must be accompanied by an overall project plan that includes the location, dimensions, and supporting analyses of all detention/retention facilities, primary conveyance facilities, and outlet conditions. Construction plans need to include the following detailed items:
1. Title sheet which includes location map, vicinity map, operating authority, design company name, developer name, and index of plan sheets;
2. A copy of a legal boundary survey for the site, performed in accordance with IAC Rule 12 of Title 865 or any applicable and subsequently adopted rule or regulation for the subdivision limits, including all drainage easements and wetlands;
3. A reduced plat or project site map showing the parcel identification numbers, lot numbers, lot boundaries, easements, and road layout and names. The reduced map must be legible and submitted on a sheet or sheets no larger than 11 inches by 17 inches for all phases or sections of the project site;
4. An existing project site layout that must include the following information:
a. A topographic map of the land to be developed and such adjoining land whose topography may affect the layout or drainage of the development. The contour intervals shall be one foot when slopes are less than or equal to 2% and shall be two feet when slopes exceed 2%. All elevations shall be given in North American Vertical Datum of 1988 (NAVD). The horizontal datum of topographic map shall be based on State Plane Coordinates, NAD83, as amended or updated. The map will contain a notation indicating these datum information. The names of adjoining property owners must be labeled on the map.
i. If the project site is less than or equal to two acres in total land area, the topographic map shall include all topography of land surrounding the site to a distance of at least 100 feet.
ii. If the project site is greater than two acres in total land area, the topographic map shall include all topography of land surrounding the site to a distance of at least 200 feet.
b. Location, name, and normal water level of all wetlands, lakes, ponds, and water courses on or adjacent to the project site;
c. Location of all existing structures on the project site;
d. One hundred-year floodplains, floodway fringes, floodways, and date reference information used to establish such. Please note if none exists;
e. Identification and delineation of vegetative cover such as grass, weeds, brush, and trees on the project site;
f. Location of storm, sanitary, combined sewer, and septic tank systems and outfalls;
g. Apparent land use of all adjacent properties;
h. Identification and delineation of sensitive areas;
i. The location of regulated drains, farm drains, inlets, and outfalls, if any of record, along with recordation number, and the like;
j. Location of all existing cornerstones within the proposed development and a plan to protect and preserve them; and
k. Date topographic survey (field work) was performed.
5. A grading and drainage plan, including the following information:
a. All information from the existing site layout items listed above;
b. Location of all proposed site improvements, including roads, utilities, lot delineation and identification, proposed structures, and common areas, along with finished floor elevations of all living areas;
c. One hundred-year floodplains, floodway fringes, floodways, and date reference information used to establish such. Please note if none exists;
d. Delineation of all proposed land-disturbing activities, including off-site activities that will provide services to the project site;
e. Information regarding any off-site borrow, stockpile, or disposal areas that are associated with a project site, and under the control of the project site owner;
f. Existing and proposed topographic information at a contour interval appropriate to indicate drainage patterns;
g. Location, size, and dimensions of all existing streams to be maintained, and new drainage systems such as culverts, bridges, storm sewers, conveyance channels, and 100-year overflow paths/ponding areas shown as hatched areas, along with all associated easements;
h. Pipes and associated structures data, including sizes, lengths, and material;
i. Location, size, and dimensions of features such as permanent retention or detention facilities, including natural or constructed wetlands, used for the purpose of stormwater management. Include existing retention or detention facilities that will be maintained, enlarged, or otherwise altered and new ponds or basins to be built;
j. Emergency flood routing path(s) and their invert elevations from detention facilities to the receiving system;
k. One or more typical cross-sections of all existing and proposed channels or other open drainage facilities (including existing retention or detention facilities) carried to a point above the 100-year high water and showing the elevation of the existing land and the proposed changes, together with the high water elevations expected from the 100-year storm under the controlled conditions called for by this subchapter, and the relationship of structures, streets, and other facilities;
l. A drainage summary, which summarizes the basic conditions of the drainage design, including site acreage, off-site/upstream acreage, allowable release rates, post-developed 10-year, and 100-year flows leaving the site, volume of detention required, volume of detention provided, and any release rate restrictions;
m. Arrows designating the direction of stormwater runoff; and
n. Spot elevations appropriate to define elevations.
6. Utility plan sheet(s) showing the location of all existing and proposed utility lines for the project, including all available information related to the utilities, such as pipe size and material, and invert elevations;
7. Storm sewer plan/profile sheet(s) at a scale of five vertical and 50 horizontal showing the elevation, size, length, location of all proposed storm sewers. Existing and proposed ground grades, storm sewer structures elevations, and utility crossings also must be included. The actual correct datum (not an assumed one) must be used for the profile sheets and all pipe inverts, top of casting elevations, casting types, structure numbers, and pipe slopes clearly labeled;
8. A plat on the same sheet size used for recording (both in hard copy and digital format acceptable to the city), including the following information:
a. Legal description;
b. Cross reference to Rule 12; and
c. Regulated drain statement and table.
9. Proposed subdivision landscape plans;
10. A copy of the subdivision covenants; and
11. Any other information required by the city in order to thoroughly evaluate the submitted material.
(c) Stormwater drainage technical report. A written stormwater drainage technical report must contain a discussion of the steps taken in the design of the stormwater drainage system. Note that in order to gain an understanding of and to evaluate the relationship between the proposed improvements for a specific project section/phase and the proposed improvements for an overall multi-section (phased) project, the detailed information requested herein for the first section/phase being permitted must be accompanied by an overall project plan that includes the location, dimensions, and supporting analyses of all detention/retention facilities, primary conveyance facilities, and outlet conditions. The technical report needs to include the following detailed items:
1. A summary report, including the following information:
a. Description of the nature and purpose of the project;
b. The significant drainage problems associated with the project;
c. The analysis procedure used to evaluate these problems and to propose solutions;
d. Any assumptions or special conditions associated with the use of these procedures, especially the hydrologic or hydraulic methods;
e. The proposed design of the drainage control system;
f. The results of the analysis of the proposed drainage control system showing that it does solve the project’s drainage problems and that it meets the requirements of the ordinance and these standards. This must include a table summarizing, for each eventual site outlet, the pre-developed acreage tributary to each eventual site outlet, the unit discharge allowable release rate used, the resulting allowable release rate in cfs for the post-developed 10-year and 100-year events, pre-developed two-year flow rates in cfs as well as pre- and post-developed flow rates for 10- and 100-year events. The worksheet provided in the city’s “Stormwater Technical Standards Manual” as Table 6-1 must be filled and submitted as part of the report. Any hydrologic or hydraulic calculations or modeling results must be adequately cited and described in the summary description. If hydrologic or hydraulic models are used, the input and output files for all necessary runs must be included in the appendices. A map showing any drainage area subdivisions used in the analysis must accompany the report;
g. Soil properties, characteristics, limitations, and hazards associated with the project site and the measures that will be integrated into the project to overcome or minimize adverse soil conditions;
h. A narrative and photographic record of the condition of the downstream receiving system; and
i. Identification of any other state or federal water quality permits that are required for construction activities associated with the owner’s project site. Proof of errors and omissions insurance for the registered professional engineer or licensed land surveyor showing a minimum amount of $1,000,000 in coverage.
2. A hydrologic/hydraulic analysis, consistent with the methodologies and calculation included in the city’s “Stormwater Technical Standards Manual”, and including the following information:
a. A hydraulic report detailing existing and proposed drainage patterns on the subject site. The report must include a description of present land use and proposed land use. Any off-site drainage entering the site or any downstream restrictions must be addressed as well. This report must be comprehensive and detail all of the steps the engineer took during the design process;
b. All hydrologic and hydraulic computations must be included in the submittal. These calculations must include, but are not limited to, the following: runoff curve numbers and runoff coefficients, runoff calculations, stage-discharge relationships, times-of-concentration, and storage volumes;
c. Copies of all computer runs. These computer runs must include both the input and the outputs. Electronic copies of the computer runs with input files must also be included;
d. A set of exhibits must be included showing the drainage sub-areas and a schematic detailing of how the computer models were set up;
e. A conclusion which summarizes the hydraulic design and details how this design satisfies this subchapter; and
f. Signed and certified (stamped) by a professional engineer or licensed surveyor registered in the state.
(d) Stormwater pollution prevention plan for construction sites. Construction sites with total disturbance of one acre or more, or construction sites with a high probability of runoff impact on a waterbody or drainage system, must provide a stormwater pollution prevention plan associated with construction activities that are designed to, at a minimum, meet the requirements of this subchapter and must include the following information: construction sites with land disturbances totaling less than one acre must provide appropriate erosion and sediment control measures that are consistent with the city’s technical standards must be designed and shown on the plans.
1. Location, dimensions, detailed specifications, and construction details of all temporary and permanent stormwater quality measures;
2. Soil map of the predominant soil types, as determined by the United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS) Soil Survey, or as determined by a soil scientist. Hydrologic classification for soils must be shown when hydrologic methods requiring soils information are used. A soil legend must be included with the soil map;
3. Fourteen-Digit Watershed Hydrologic Unit Code;
4. An estimate of the peak discharge, based on the ten-year storm 24-hour event, of the project site for post-construction conditions;
5. Locations where stormwater may be directly discharged into groundwater, such as abandoned wells or sinkholes. Please note if none exists;
6. Locations of specific points where stormwater discharge will leave the project site;
7. Name of all receiving waters. If the discharge is to a separate municipal storm sewer, identify the name of the municipal operator and the ultimate receiving water;
8. Temporary stabilization plans and sequence of implementation;
9. Permanent stabilization plans and sequence of implementation;
10. Temporary and permanent stabilization plans shall include the following:
a. Specifications and application rates for soil amendments and seed mixtures; and
b. The type and application rate for anchored mulch.
11. General construction sequence of how the project site will be built, including phases of construction and the associated time of year they are expected to be done;
12. Construction sequence describing the relationship between implementation of stormwater quality measures and stages of construction activities;
13. Location of all soil stockpiles and borrow areas;
14. A typical erosion and sediment control plan for individual lot development;
15. Self-monitoring program including plan and procedures;
16. A description of potential pollutant sources associated with the construction activities, which may reasonably be expected to add a significant amount of pollutants to stormwater discharges;
17. Material handling and storage associated with construction activity shall meet the spill prevention and spill response requirements in 327 IAC 2-6.1; and
18. Name, address, telephone number, and list of qualifications of the trained individual in charge of the mandatory stormwater pollution prevention self-monitoring program for the project site.
(e) Post-construction stormwater pollution prevention plan. The post-construction stormwater pollution prevention plan must include the following information:
1. A description of potential pollutant sources from the proposed land use, which may reasonably be expected to add a significant amount of pollutants to stormwater discharges;
2. Location, dimensions, detailed specifications, and construction details of all post-construction stormwater quality measures;
3. A description of measures that will be installed to control pollutants in stormwater discharges that will occur after construction activities have been completed. Such practices include infiltration of runoff, flow reduction by use of open vegetated swales and natural depressions, buffer strip and riparian zone preservation, filter strip creation, minimization of land disturbance and surface imperviousness, maximization of open space, and stormwater retention and detention ponds;
4. A sequence describing when each post-construction stormwater quality measure will be installed;
5. Stormwater quality measures that will remove or minimize pollutants from stormwater run-off;
6. Stormwater quality measures that will be implemented to prevent or minimize adverse impacts to stream and riparian habitat; and
7. An operation and maintenance manual (in a separate cover) for all post-construction stormwater quality measures to facilitate their proper long term function. This operation and maintenance manual shall be made available to future parties who will assume responsibility for the operation and maintenance of the post-construction stormwater quality measures. The manual shall include the following:
a. Contact information for the BMP owner (i.e., name, address, business phone number, cell phone number, pager number, e-mail address, and the like);
b. A statement that the BMP owner is responsible for all costs associated with maintaining the BMP;
c. A right-of-entry statement allowing city personnel to inspect and maintain the BMP;
d. Specific actions to be taken regarding routine maintenance, remedial maintenance of structural components, and sediment removal. Sediment removal procedures must be explained in both narrative and graphical forms. A tabular schedule must be provided listing all maintenance activities and dates for performing these required maintenance activities; and
e. Site drawings showing the location of the BMP and access easement, cross-sections of BMP features (i.e. pond, forebay(s), structural components, and the like), and the point of discharge for stormwater treated by the BMP. These drawings need to be submitted both in hard copy and in digital format acceptable to the city.
(D) Information requirements: development of individual lots disturbing or impacting between 10,000 square feet and one acre.
(1) Individual lots disturbing or impacting between 10,000 square feet and one acre, either individually or as part of a larger permitted project, must submit an individual stormwater pollution prevention plan, in the form of a lot plot plan, with an improvement location permit. All stormwater management measures for individual lots within a larger permitted project must, at a minimum, be implemented in accordance with the permitted plan for the larger project.
(2) The following information must be submitted by the individual lot operator to the city for review:
(a) Information required under § 155.098 of the Unified Development Ordinance.
(b) Erosion and sediment control plan that, at a minimum, includes the following measures:
1. Installation and maintenance of a stable construction site access;
2. Installation and maintenance of appropriate perimeter erosion and sediment control measures prior to land disturbance;
3. Minimization of sediment discharge and tracking from the lot;
4. Clean-up of sediment that is either tracked or washed onto roads. Bulk clearing of sediment shall not include flushing the area with water. Cleared sediment must be redistributed or disposed of in a manner that is in compliance with all applicable statutes and rules;
5. Adjacent lots disturbed by an individual lot operator must be repaired and stabilized with temporary or permanent surface stabilization; and
6. Self-monitoring program including plan and procedures.
(c) Certification of compliance stating that the individual lot plan is consistent with the stormwater management permit, as approved by the city for the larger project; and
(d) Name, address, telephone number, and list of qualifications of the trained individual in charge of the mandatory stormwater pollution prevention self-monitoring program for the project site.
(3) The individual lot operator is responsible for installation and maintenance of all erosion and sediment control measures until the site is stabilized.
(E) Changes to plans. Any changes or deviations in the detailed plans and specifications after approval of the applicable stormwater pollution prevention plan shall be filed with, and accepted by, the city prior to land development involving the change. Copies of the changes, if accepted, shall be attached to the original plans and specifications.
(F) Fee structure.
(1) Fee amount. As a condition of the submittal and the review of development plans by the city, the applicant shall pay the city the applicable fee, as set by the Board, with respect to the review of all drainage submittals, preliminary plans, final plans, construction plans, and accompanying information and data, as well as any applicable pre-paid inspection fees.
(2) Time of payment.
(a) Before the city’s approval of plans, the city will furnish a written statement to the applicant specifying the total amount due the city in connection with the review of the applicant’s submittals, plans, and accompanying information and data, including the amount required to be paid by the applicant for review and pre-paid inspection fees.
(b) As a condition of acceptance of final drainage plans by the city, the applicant shall pay to the city the sum set forth in said statement. The city may issue such a billing statement before the project advances to the final acceptance stage, and such payment is due by the applicant upon receipt of said billing statement regardless of whether the project is advanced to the final acceptance stage.
(c) The city shall have the right to not accept the drainage improvements or to not accept the advancement of any project for which the applicable fees have not been paid.
(3) Method of payment.
(a) Fees shall be paid by one of the following methods:
1. Check;
2. Credit card;
3. Money order; or
4. Such other methods as may be agreed in writing by the city.
(b) All checks shall be made payable to the city’s Stormwater Utility.
(4) Refund of payment. Fees are refundable or may be waived only if the city determines that compliance by the applicant with this subchapter is not necessary.
(G) Required performance assurances. As a condition of approval and issuance of the permit, the city shall require the applicant to provide assurance in the form of an irrevocable letter of credit, a performance bond, or such other instrument or method of security acceptable in writing by the city when the stormwater management plan has been accepted, all applicable fees paid, and before construction begins. Said assurance will guarantee a good faith execution of the stormwater drainage plan, the stormwater pollution prevention plan, the stormwater quality management plan, and any permit conditions. The assurance shall be for an amount equal to at least 110% of the total costs of all stormwater management measures for the entire project. The above mentioned costs shall be based on an estimate as prepared by a professional engineer or land surveyor registered in the state. Said costs shall be for the installation and ongoing monitoring and maintenance of erosion control measures and the construction and ongoing monitoring and maintenance of storm drainage infrastructure, detention/retention facilities, and stormwater quality BMPs, as regulated under this subchapter, until the construction is completed, site is stabilized, and as-built plans are accepted by the city. Assurances shall be for a minimum of $5,000. The intent of this assurance is not only to complete the installation of storm drain infrastructure for the project, but also to assure that adequate stormwater pollution prevention measures are properly installed and maintained. If adequate assurances are set aside by the project site owner for the overall project, proof of total assurance can be submitted in place of an individual stormwater assurance.
(H) Terms and conditions of permits.
(1) In granting a stormwater management permit, the city may impose such terms and conditions as are reasonably necessary to meet the purposes of this subchapter. The project site owner shall ensure compliance with such terms and conditions. Non-compliance with the terms and conditions of permits will be subject to enforcement as described in § 54.33.
(2) The project site owner shall inform all general contractors, construction management firms, grading or excavating contractors, utility contractors, and the contractors that have primary oversight on individual building lots of the terms and conditions of the stormwater management permit and the schedule for proposed implementation.
(3) It is the intent of this subchapter to direct the community’s physical growth away from sensitive areas and towards areas that can support it without compromising water quality. In the event that a project site is determined to impact or discharge to a sensitive area or is located in an impact drainage area, the city may require more stringent stormwater quantity and quality measures than detailed in this subchapter or in the latest edition of the state’s “Stormwater Quality Manual”.
(a) Determination of sensitive areas. Sensitive areas include highly erodible soils, wetlands, threatened or endangered species habitat, outstanding waters, impaired waters, recreational waters, and surface drinking water sources. A listing of highly erodible soils, outstanding water, impaired water, recreation water, and surface drinking water sources can be found in the city’s “Stormwater Quality Management Plan (SWQMP)” - Part B, dated October 8, 2004 and its updates. Any discharge from a stormwater practice that is a Class V injection well shall meet the state’s groundwater quality standards. If wetlands are suspected on a site, wetland delineation shall be completed in accordance with the methodology established by the U.S. Army Corps of Engineers (COE) and the wetland addressed in accordance to the COE requirements. If the presence of threatened or endangered species habitat is suspected on a site, the site must be evaluated and inspected by a professional experienced in such and the results reported to the city. Special terms and conditions for development determined to impact or discharge to any sensitive area shall be included in the stormwater management permit.
(b) Determination of impact drainage areas.
1. The following areas shall be designated as impact drainage areas, unless good reason for not including them is presented to the city:
a. A floodway or floodplain as designated by the most updated city code dealing with floodplain regulation;
b. Land within 75 feet of each bank of any ditch within the county’s regulated drainage system; and
c. Land within 75 feet of the centerline of any drain tile or enclosed conduit within the county’s regulated drainage system.
2. The Board is authorized, but is not required, to classify certain additional geographical areas as impact drainage areas. In determining impact drainage areas, the Board shall consider such factors as land use, topography, soil type, capacity of existing drains, and distance from adequate drainage facility.
3. Land that does not have an adequate outlet, taking into consideration the capacity and depth of the outlet, may be designated as an impact drainage area by the Board. Special terms and conditions for development within any impact drainage area shall be included in the stormwater management permit.
(I) Certification of as-built plans. After completion of construction of the project and before final project acceptance of the stormwater management plan (the issuance of a “verified” NOT), a professionally prepared and certified “as-built” set of plans (record drawings) by a professional engineer or licensed land surveyor registered in the state shall be submitted to the city for review. These as-built plans/record drawings must be prepared and certified by the engineer of record, i.e., the company/engineer who originally prepared the construction plans. Additionally, a digital copy of the “as-built” plans (record drawings) as well as finalized digital versions of all analyses, models, manuals, and reports that are consistent with the as-built conditions are required in a format accepted by the city. These plans shall include all pertinent data relevant to the completed storm drainage system and stormwater management facilities, and shall include:
(1) Pipe size and pipe material;
(2) Invert elevations;
(3) Top rim elevations;
(4) Pipe structure lengths;
(5) BMP types, dimensions, and boundaries/easements;
(6) “As-planted” plans for BMPs, as applicable;
(7) Data and calculations showing detention basin storage volume;
(8) Data and calculations showing BMP treatment capacity; and
(9) Certified statement on plans stating the completed storm drainage system and stormwater management facilities substantially comply with construction plans and the stormwater management permit as approved by the city. (See certificate in “Stormwater Technical Standards Manual”.)
(J) Required maintenance assurances.
(1) The property owner, developer, or contractor shall be required to file a three-year maintenance bond or other acceptable guarantee with the city, prior to final project acceptance (the issuance of a “verified” NOT), in an amount not to exceed 20% of the cost of the stormwater drainage system located outside the public road right-of-ways, and in a form satisfactory to the City Attorney in order to assure that such stormwater system installation was done according to standards of good workpersonship, that the materials used in the construction and installation were of good quality and construction, and that such project was done in accordance with the accepted plans, and this subchapter. The bond or other acceptable guarantee shall be in effect for a period of three years after the date of the final project acceptance by the city.
(2) To verify that all enclosed drains are functioning properly, visual recordings (via closed circuit television) of such tile drains shall be required, once following the completion of installation (including the installation of all utility mains) and the second time before release of maintenance bonds. These visual recordings will be scheduled by the city, and paid for by the developer. Notices shall be provided to the city within 72 hours following the completion of installation and again at least 60 days prior to the expiration date of the maintenance bond so that the noted recordings may be scheduled. Reports summarizing the results of the noted visual recordings shall be reviewed and accepted by the city before the improvement is recommended for recording and again before maintenance bond would be recommended to be released.
(K) Permit approval process flowchart.
(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)