(A) A drainage plan fulfilling the requirements of this subchapter and Board regulations shall be submitted to the Board for approval before a drainage permit can be obtained to accomplish a land alteration, unless the land alteration is such that a drainage permit can be obtained in accordance with § 152.21. The drainage plan must be submitted in triplicate, and shall indicate in a precise way the work to be accomplished pursuant to the drainage permit. One copy of the drainage plan will remain on file with the Board.
(B) The following information must be submitted for approval.
(1) Construction features. The drainage plan shall demonstrate and describe surface and subsurface drainage and include the following.
(a) Scale; arrow; contours and USGS bench marks. The drainage plan shall be drawn to scale, preferably one inch per 50 feet, and an arrow indicating north shall appear on each page. Existing land contours shall be shown, with one-foot contours for land with a slope flatter than 10%, two-foot contours for slopes equal to or greater than 10% but flatter than 20%, and five-foot contours for slopes equal to or greater than 20%. A bench mark, which is easily accessible and relocatable, shall be shown. The bench mark may be assumed at the discretion of the Board if the area contains less than three acres, but otherwise shall be determined by USGS datum.
(b) Location and vicinity map. A map which indicates the location and vicinity of the proposed land alteration shall be included in the drainage plan.
(c) Existing and proposed drainage facilities. The drainage plan shall show the locations of all existing and proposed drainage facilities. Storm drains and manholes and other structures shall be located in the plans by dimensions from property markers or road centerlines. If applicable, the drainage plan should show the direction of flow, elevation of inverts, gradient, size and capacity of existing and proposed storm drains. When using existing storm drains, the capacity shall be indicated.
(d) Plan and profile. The plan shall be shown at the upper portion of the drawing. The plan, generally, shall be drawn on a scale of one inch equals 50 feet. The plan shall show appropriate right-of-way and easement limits. The profile shall be shown under the plan and shall extend a sufficient distance downstream of the outlet to allow any pertinent information concerning the outfall channel to be shown. The storm drain and inlet profile shall generally be drawn on a scale of one inch equals 50 feet horizontal, one inch equals five feet vertical. Where a storm drain is located in an existing or proposed pavement or shoulder, the centerline grade of the road shall be shown. Where a storm drain is located outside pavement or shoulder, the existing ground over the storm drain with proposed grading shall be shown with the centerline grade of the road. If the storm drain is to be constructed on fill, the profile of the undisturbed earth, at drain location, shall be shown.
(2) Design calculations.
(a) Design calculations are required as part of the drainage plan and shall specifically include:
1. Estimation of storm water runoff:
a. Drainage area map (scale one inch equals 200 feet) indicating contours at two-foot intervals and limits of 100-year floodplain, where applicable;
b. Weighted runoff coefficient computations;
c. Time of concentration computation indicating overland flow time and flow time in the swale, gutter, pipe or channel;
d. All drainage facilities shall be designed for a 25-year design storm. All runoffs shall be calculated using the rational method, using the rainfall intensity frequency duration curve for Evansville, Indiana, as promulgated by the United States Department of Commerce - Weather Bureau Cooperative Studies Section; and
e. Starting time duration shall be ten minutes.
2. Closed conduit and open channel design computations:
a. Size of pipe or channel cross-section;
b. Pipe or channel invert’s slope in percent;
c. Roughness coefficient;
d. Flow velocities in feet per second; and
e. Design capacity in cubic feet per second.
3. Head loss computations in manholes and junction chambers;
4. Hydraulic gradient computations, wherever applicable; and
5. Erosion control methods.
(b) Such design calculations shall conform with the standards of the Board and all regulations promulgated thereunder.
(3) Additional information. The Board shall be empowered to require such additional information to be included in a drainage plan that is necessary to evaluate and determine the adequacy of the proposed drainage facility.
(4) Certification required. All drainage plans submitted under this section to the Board for approval must be certified by a registered professional engineer, land surveyor or architect engaged in storm drainage design under whose supervision the plans were prepared. The certificate shall be in the following form:
CERTIFICATE OF SUFFICIENCY OF PLAN
|
CERTIFICATE OF SUFFICIENCY OF PLAN
|
Permit Number |
Address where land alteration occurring |
Plan Date |
I hereby certify that to the best of my knowledge and belief: |
(1) The drainage plan for this project is in compliance with the drainage requirements of the Town of Newburgh pertaining to this class of work. |
(2) The calculations, designs, reproducible drawings, masters and original ideas reproduced in this drainage plan are under my dominion and control and they were prepared by me and my employees. |
Signature Date |
Typed or Printed Name Phone |
(SEAL) |
Business Address |
Surv. Eng. Arch. |
Indiana Registration No. |
(5) Obligation to observe. All drainage plans submitted under this section to the Board must include a certificate of obligation to observe by a registered professional engineer, land surveyor or architect engaged in storm drainage design. The certificate shall be in the following form:
CERTIFICATE OF OBLIGATION TO OBSERVE
|
CERTIFICATE OF OBLIGATION TO OBSERVE
|
Permit Number |
Address where land alteration occurring |
Plan Date |
I will perform periodic observations of this project during construction to determine that such land alteration is in accordance with both the applicable drainage requirements and the drainage plan for this project submitted for a drainage permit to the Department of Storm Water Management. |
Signature Date |
Typed or Printed Name Phone |
(SEAL) |
Business Address |
Surv. Eng. Arch. |
Indiana Registration No. |
(1991 Code, § 134.15)