Before commencing any commercial, institutional, multi-family, or industrial or industrial project with an area of more than one-half acre, or a project requiring subdivision approval by a unit of local government with an area of more than one-half acre, the owner of the land or his or her representative shall be required to file an application for an erosion, sediment, and stormwater control permit.
(A) Application. The applicant shall file the application with the Department on forms provided by the Department. The applicant shall supply the number of copies of application documents as provided in the application. Each application shall be accompanied by the following information:
(1) A map of existing site conditions on a scale of at least one inch equals 100 feet, showing the site and immediately adjacent areas and the locations of the following site information:
(a) Site boundaries and adjacent lands which accurately identify site location;
(b) Lakes, streams, wetlands, channels, ditches, and other watercourses on and immediately adjacent to the site;
(c) Floodways and/or Zone A of the floodplain as determined on the flood insurance rate map (FIRM) and indicating the map panel number;
(d) All off-site drainage onto or through the project site;
(e) Location and dimensions of stormwater management systems on or adjacent to site;
(f) Locations and dimensions of structures, roads, highways, easements, and paved areas; and
(g) Site topography: show contours at vertical intervals as follows:
1. Slope of 6% or less: two-foot intervals;
2. Slope of over 6% but less than 15%: five-foot intervals; and
3. Slope of over 15%: ten- or 20-foot intervals.
(2) A plan of final site conditions drawn to the same scale as the existing site map submitted pursuant to division (A)(1) above, and which includes information to accurately depict post-construction appearance of site (e.g., paved areas, buildings, landscaping, and other changes to the site), along with other predominant site features (e.g., open areas, bodies of water);
(3) Sediment and erosion control practices. A site construction plan including:
(a) Locations and dimensions of all proposed land disturbing activities;
(b) Locations and dimensions of all temporary soil and aggregate stockpiles;
(c) Location, dimensions, and construction details of all construction site management control measures necessary to meet the requirements of this chapter, and including proposed re- vegetation of disturbed areas; and
(d) Statement regarding provisions for maintenance and maintenance requirements of the construction site management control measures during construction;
(4) Stormwater management plans and controls. Design calculations and information related to the permanent stormwater management system for any project with a net increase of impervious area greater than one-half of an acre. For the purposes of this section, the net increase is the cumulative change since the implementation of this chapter, April 15, 1996. For example, in year one, a commercial site increases the parking lot by 20,000 square feet. In year two, the same commercial site adds a building with an area of 20,000 square feet. In year one, no permanent stormwater control measures (or calculations) are required by the chapter. In year two, stormwater calculations shall be submitted and shall be based on the total increase of 40,000 square feet of impervious area. The following information shall also be provided by the applicant:
(a) A map showing the drainage area divides, including off-site drainage areas that drain into the site;
(b) Location and identification of soil types for entire watershed;
(c) Location and identification of vegetative cover for entire watershed;
(d) Runoff curve number calculations for both pre- and post-project conditions for all sub- watersheds;
(e) Time of concentration calculations for both pre- and post-project conditions for all sub- watersheds, and include a map showing hydraulic flow lengths used;
(f) Peak flow-rate calculations for two-year and 25-year storms for both pre- and post- project conditions;
(g) Design calculations for detention basin outlets for both two-year and 25-year storms, include stage-storage table and discharge rating curve data or outflow calculations (refer to optional form in § 151.12);
(h) Location dimensions and construction details of proposed detention basins and outlets;
(i) Detention volume calculations; and
(j) Summary of peak flow-rates for pre, post, and proposed conditions with detention showing that the requirements of the chapter are met (refer to optional form in § 151.12).
(5) Schedule or sequence of development or installation of the elements of the site management control measures proposed above;
(6) A detailed estimate of quantities and estimated costs, prepared by a registered professional engineer, of all control measures required under this section;
(7) A plan of the continued management and maintenance of such permanent control measures; and
(8) An application fee shall be submitted at the time of application. The fee shall be in the amount of $75 per acre with a minimum fee of $450 and a maximum fee of $3,000. However, no fee shall be required for any project, the purpose of which is agricultural. A fractional acre shall be rounded to the nearest whole acre. There shall be no refund of any fees paid and no application shall be accepted for filing unless the fee has been paid in full.
(B) Application review. Within five working days of submittal of the application, the Erosion Control Administrator shall respond in writing to the sediment and erosion control practices portion. Within 20 working days the Erosion Control Administrator shall respond to the stormwater management plans and control portion of the application by either issuing a permit, issuing a request for additional information, or issuing a statement denying the permit with an explanation of cause. The application shall be deemed approved if no response is made within the time frames stipulated above.
(C) Financial security agreement. Before any erosion sediment and stormwater control permit is issued, the applicant shall deliver to the Erosion Control Administrator a cash bond in the name of the county for 100% of the applicant’s engineer’s estimated cost for all control measures required under this section. Said cash bond will be delivered by the Erosion Control Administrator to the County Treasurer and deposited in an interest bearing escrow account in a county bank with interest to be paid to the applicant. Each security shall be accompanied by an agreement executed by the applicant, and approved by the Erosion Control Administrator, wherein the applicant agrees to install and maintain all maintenance control measures and specifying a date of completion in accordance with this chapter. If the control measures are necessitated by construction which is also subject to Chapter 155, the applicant may submit cash bond to cover 100% of both the control measures required pursuant to this section and the improvements governed by Chapter 155. A signed contractor’s bid that meets the specifications of the engineer’s estimate for the work can be used to establish the amount of security required, if such estimate is accepted by the Erosion Control Administrator.
(D) Duration. The erosion sediment and stormwater control permit shall be issued for a period not exceeding two years.
(E) Permit conditions. The erosion sediment and stormwater control permit shall contain, at a minimum, the following general conditions:
(1) The written approval shall be obtained from the Erosion Control Administrator prior to making any modification to the approved erosion and sediment control plan as set forth in the permit;
(2) All control measures required in the permit shall be installed;
(3) All control measures shall be maintained during construction; and
(4) Such other conditions as the Erosion Control Administrator deems appropriate.
(F) Permanent ground surface cover. Without exception, all disturbed areas must have permanent ground cover within six months of project completion or within six months of occupancy, whichever comes first.
(G) Final inspection-notice of permanent stormwater control measures. Within 14 days after completion of construction, the applicant may notify the Erosion Control Administrator that the permanent stormwater control measures are ready for final inspection. If the inspection shows that the control measures and maintenance plan comply with the standards in § 151.12, the Erosion Control Administrator shall issue a notice of permanent stormwater control measures. The owner shall record the notice with the County Recorder of Deeds within 15 days after the notice is issued.
(Prior Code, 8 TCC 3-6) (Amended 3-26-2008)