(A) General requirements.
(1) Development activity shall not be conducted unless appropriate erosion and sedimenta- tion facilities are designed, installed and maintained throughout the life of the development.
(2) All erosion and sediment control methods shall be indicated on the final construction and/or building permit plans.
(3) All earth slopes and earth areas, new or existing, subject to erosion, such as open channels, bar ditches, areas adjacent to trickle channels, inlet structures and outlet structures, within any area designated for detention or drainage shall be solid slab sodded with Bermuda grass sod from a local source or have permanent established growth of vegetation. All vegetation areas shall be fertilized, watered and in an established growing condition with permanent vegetation prior to completion or acceptance of any storm water drainage facility, and/or development.
(B) Design considerations.
(1) General design principles. Practical combinations of the following principles shall be utilized, as a minimum, in planning measures to be installed for any land disturbing activity.
(a) The land disturbing activity shall conform to existing topography and soil type so as to create the lowest practicable erosion potential.
(b) The disturbed area and the duration of exposure of bare earth to erosive elements shall be kept to a practicable minimum through construction scheduling and management.
(c) Cut and fill operations should be kept to a minimum.
(d) Disturbed soil shall be stabilized as quickly as practicable.
(e) Natural vegetation shall be retained, protected and supplemented whenever feasible.
(f) Temporary vegetation or mulching shall be employed in a timely manner to protect exposed critical areas during development.
(g) Permanent vegetation and structural erosion control measures shall be installed prior to final acceptance of developments or as soon as seasonal planting restrictions allow.
(2) General practice. Soil and water conservation measures include, but are not necessarily restricted to, vegetation, mulches, sediment basins, dikes, grade stabilization structures, sediment traps, land grading, diversions, waterways or outlets, and riprap.
(3) Vegetative practices. Vegetative practices shall be applied to control erosion. The practice can be either temporary and/or permanent depending on the site specific needs.
(C) Erosion and sediment control criteria.
(1) Long-term permanent vegetative cover obtained through seeding, mulching, sprigging, sodding, or planting using acceptable varieties such as Bermuda grass, Kentucky 31 Tall Fescue or Weeping Lovegrass shall be used to control erosion on a permanent basis.
(2) Short-term vegetative cover through seeding or mulching using small grains like oats, rye and wheat, and sundans and sorghums, shall be used to control immediate erosion. This practice may be effective for areas where soil is left exposed for a period of six to 12 months and shall not be deemed permanent erosion control.
(3) Straw bale dikes may only be utilized where no other practice such as silt dikes or silt fences are feasible.
(4) Solid slab sod shall be used for all open channels, bar ditches, storage facilities and other steep slopes.
(5) Hay and sod mulching, as a temporary measure, may be used for embankment stabilization in other areas where surface runoff is to be directed down a slope.
(6) A coarse rock stabilized construction entrance shall be built in accordance with the standard detail drawings to reduce or eliminate the tracking or flowing of sediment onto the public right-of-way.
(7) A concrete or stone outlet structure shall be constructed in areas where the entire drainage area to the structure is not stabilized or where there is a need to dispose runoff at a protected outlet or where concentrated flow for the duration of the period of construction needs to be diffused.
(8) A grade stabilization structure in the form of a paved chute or flume shall be constructed to prevent erosion where concentrated flow of surface runoff is to be conveyed down a slope of 3% or greater.
(9) Storm water detention facilities may be used temporarily as sediment basins. A temporary outlet structure for the storm water detention facility to work as a sediment pond shall be constructed. At the end of the construction activity, the developer shall remove all collected sediment from the detention facility and outlet structure and restore/construct the facility to the approved detention design plans.
(10) The technologies and methodologies associated with erosion and sediment control are continually being developed and modified. For the current best management practices suggested for use, refer to the U.S. Environmental Protection Agency website as well as recent publications by trade organizations and others.
(D) New developments disturbing an area greater than one acre must obtain authorization to discharge under the ODEQ general permit for storm water discharge from construction activities.
(1) Notice of Intent (NOI) must be submitted to:
Storm Water Notice of Intent
Oklahoma Department of Environmental Quality
Water Quality Division
P.O. Box 1677
Oklahoma City, OK 73102-1677
(2) A copy must be submitted to the city with the erosion and sedimentation control plan.
(E) Erosion and sedimentation control plan.
(1) General. All reports shall be typed and bound together. The drawings, figures, plates, tables and site plan shall be bound with the report or included in a folder/pocket at the back of the report.
(2) Plan contents. The report shall contain the applicable information listed:
(a) General. Name, address and telephone number of the applicant, landowner developer and engineer and copy of the NOI, if required;
(b) Project description. Briefly describe the nature and purpose of the land disturbing activity, the amount of grading involved, and project location including section, range and township. Include a schedule listing the sequence of major events, such as the start of clearing/grading, installation of erosion controls, construction of sediment/storm water basins and final soil stabilization;
(c) Existing site conditions. A description of the existing topography, vegetation and drainage;
(d) Immediate adjacent areas. A description of neighboring areas such as streams, lakes, residential areas, roads and the like, which might be affected by the land disturbance;
(e) Soils. A brief description of the soils on the site giving such information as soil names, mapping unit, erosion tendencies, permeability, hydrologic soil group, depth, texture and soil structure; (This information may be obtained from the S.C.S. soil survey for Cleveland County.)
(f) Erosion and sediment control measures. A description of the methods which will be used to control erosion and sedimentation on the site;
(g) Permanent stabilization. A brief description, including specifications, of how the site will be stabilized after construction is completed. This information is optional for the initial report but may be required for the report addendum;
(h) Storm water management considerations. Explain how storm water will be handled. Determine detention requirements. This information is optional for the initial report but may be required for the report addendum; and
(i) Maintenance. A schedule of regular inspections and repair of erosion and control structures should be set fourth. This information is optional for the initial report but may be required for the report addendum.
(3) Drawing contents.
(a) General location map. A map shall be provided in sufficient detail to indicate the location of the project site. The map should be at a scale of one inch equals 1,000 feet to one inch equals 2,000 feet and should indicate the project site in relation to existing topographic, and transportation, features and land boundaries. The map shall show the drainage area of land tributary to the site. The drawing size shall be a multiple of eight and one-half inches by 11 inches.
(b) Sediment and erosion control. Map(s) of the proposed development at scale of one inch equals 20 feet to one inch equals 200 feet on 24-inch by 36-inch drawing sheets shall be included. The plan shall show the following:
1. A boundary line survey of the site on which the work is to be performed;
2. Existing topography at a maximum of two-foot contour intervals. The contour shall extend a minimum of 100 feet beyond the property line (if available);
3. Proposed topography at a maximum of two-foot contour intervals;
4. Location of any existing structure or natural feature on the site;
5. Location of any structure or natural feature on the land adjacent to the site and within a minimum of 100 feet of site boundary line. The map shall show the location of the storm sewer, channel or creek receiving storm runoff from the site;
6. Location of any proposed additional structures or development on the site, if known;
7. Limits of clearing and grading. Areas which are to be cleared and graded; and
8. Detailed drawings.
(4) Best management practices. The following best management practices (BMPs) for erosion and sedimentation control may be used singly or in combination. Equivalent BMPs may also be used. All control shall be selected, installed and maintained in accordance with manufacturer’s specifications and good engineering practices. Maintenance and implementation of the controls will be detailed in the erosion and storm water pollution control plan.
(a) Temporary best management practices.
1. Dikes;
2. Swales;
3. Silt fence. Silt fences can be constructed near the perimeter of a disturbed area to intercept sediment while allowing water to percolate through. Silt fences may not be used where there is a concentration of water in a channel or other drainage;
4. Entrances. A stabilized entrance to all construction sites shall be built to reduce or eliminate the tracking or flowing of sediment onto public right-of-way;
5. Stone outlets. A stone outlet structure shall be constructed in areas where the entire drainage area to the structure is not stabilized, or where there is a need to dispose runoff at a protected outlet, or where concentrated flow for the period of construction needs to be diffused;
6. Paved chute. A grade stabilization structure in the form of a paved chute or flume shall be constructed to prevent erosion, where concentrated flow of surface runoff is to be conveyed down a slope. The maximum allowable drainage area upstream of such a structure shall not exceed 36 acres;
7. Pipe slope drain. A grade stabilization structure in the form of a pipe slope drain shall be constructed to prevent erosion, where concentrated flow of surface runoff is to be conveyed down a slope. The maximum allowable drainage upstream of such a structure shall not exceed five acres; and
8. Temporary sedimentation basin. Storm water detention facilities may be used temporarily as sediment basins.
a. A temporary outlet structure for the storm water detention facility to work as sediment pond shall be constructed.
b. At the end of the construction activity, the developer shall make sure that the outlet structure shall meet the design requirements of a storm water detention facility.
c. Condition of the detention facility that is used as a sediment pond during construction, shall meet the following requirements at the time of acceptance.
(i) It shall be completely cleaned by the developer and be rid of any immediate maintenance needs.
(ii) It shall meet all design standards.
(b) Permanent best management practices.
1. Depending on the project layout, a division shall be constructed across a slope less than 15% to:
a. Prevent runoff from higher areas having a potential for causing erosion and thereby interfere with the establishment of vegetation on lower areas; or
b. Reduce the length of slopes to minimize soil loss.
2. Divisions need be constructed only below stabilization or protected areas.
3. Outlets from divisions shall be constructed to discharge in such a manner as not to cause erosion. Outlets shall be constructed and stabilized prior to the operation of diversion.
4. Storm drain outlet protection shall be provided when converting pipe flow to channel flow. The reduction in velocity shall be consistent with the roughness coefficient of the receiving waterway. The reduction in velocity may be accomplished by:
a. Providing mortared riprap stabilization;
b. Providing energy dissipaters; and
c. Providing permanent vegetation, depending on the site specific needs.
(c) Vegetation best management practices.
1. Vegetation practices. Vegetation practices can be applied very effectively to control erosion. The practice can be either temporary or permanent depending on the site specific needs. The specifications for establishing vegetation both temporary and permanent are briefly outlined below:
2. Temporary practices.
a. Small grains like oats, rye and wheat, and sorghums are the most feasible temporary vegetation to control erosion. This practice is effective for areas where soil is left exposed for a period of six to 12 months. The time period may be shorter during periods of erosion rainfall.
b. Prior to seeding, needed erosion control practices such as diversions, grade stabilization structures, berms, dikes and the like, shall be installed.
c. Temporary vegetative practice is usually applied prior to the completion of final grading of the site.
d. If the area to be seeded has been recently loosened to the extent that an adequate seedbed exists, no additional treatment is required. However, if the area to be seeded is packed, crushed and hard, the top layer of soil shall be loosened by other suitable means.
e. Fertilizer shall be applied at a rate of 600 pounds per acre or 15 pounds per 1,000 square foot using 10-20-10, or equivalent.
f. Soils known to be highly acidic shall be lime treated.
g. Seeding requirements shall be as specified by the local NRCS office.
h. Seeds shall be drilled uniformly.
i. Seeding implements should be used at right angles to the general slope to minimize erosion.
j. After two to three months of planting, the seeded site shall be top dressed with eight pounds per 1,000 square feet or 350 pounds per acre of 33-0-0.
k. Areas that are not well covered shall be replanted.
l. The seeded area shall be watered when feasible and needed.
3. Permanent practices. Bermuda grass, Kentucky 31 Tall Fescue and Old World Blue Stem are some of the permanent vegetation that could be effectively used to control erosion.
a. Prior to seeding, needed erosion control practices such as dikes, swales, diversions, and the like shall be installed.
b. The subgrade shall be loosened evenly to a depth of two to three inches and 10-20-10 fertilizer (ten pounds per square feet or 450 pounds per acre) shall be mixed with loosened surface soil by disking or other suitable means.
c. Soils known to be highly acidic shall be lime treated.
d. Planting rate require- ments shall be as specified by the local NRCS office.
e. Seeds shall be drilled uniformly.
f. Seeding implements should be used at right angles to general slope to minimize erosion.
g. Mulch will be used where needed.
h. The area shall be watered daily, or as often as necessary to maintain adequate soil moisture until the plants grow about one-half to one inch.
4. Buffer strips. A vegetated buffer strip will be preserved along both sides of all perennial and intermittent streams and adjacent wetlands. The size and location of the buffer strip will be determined during review of the erosion and sedimentation control plan, prior to any earth disturbing activity. The naturally occurring vegetation in the buffer strip shall not be disturbed. If any vegetation in the buffer strip is disturbed, it shall be immediately restored as much a possible to its natural condition.
(d) Compliance.
1. Inspections. The city or its authorized representative shall be permitted at all times to gain access to any site for purpose of inspection or observation to determine compliance with this section.
2. Stop work order/revocation of permit. In the event that any person violates the terms of this section, the city may require a stoppage of work on the site until all violations are corrected. Any person engaged in activities regulated by this section without first obtaining the required approval, will be required to stop all work on the site until approval is obtained.
3. Violation. Any person found in violation of the provisions of this section will be denied issuance of any other permits, approvals or inspections until the violation(s) is/are corrected, or written arrangements to correct the violation(s) are submitted to and accepted by the city.
(2002 Code, § 153.091) (Ord. 651, passed 10-26-2009)