11.04.05.06

.06 General Information.

A. Plans for commercial sites should be submitted to the Administration for review after the developer takes an option or acquires title to the property. The Administration will review the tentative plans and inform the prospective developer whether or not the plans as submitted comply with the duly promulgated regulations of the State Highway Administration.

B. The permittee or owner is responsible for carrying storm water to an outfall in a manner acceptable to the State Highway Administration. Acceptable outfalls, and their associated contributing drainage facilities, shall meet the design criteria set forth by the Administration. Storm water management plans shall address, treat, and manage both on-site improvements and roadway improvements within State right of way to the Administration's satisfaction. In cases where the proposed site storm drainage facilities:

(1) Are not tied into existing highway drainage facilities, storm water management plans should be reviewed and approved by a county, a soil conservation district, or the State Water Resources Administration, or all of these. The discharge rate after development may not exceed the rate before development for the 2-, 10-, and, in some instances, the 100-year storm events. The State Highway Administration will institute legal proceedings upon being damaged by increased storm water runoff to recover any costs and to avoid recurrence.

(2) Connect to existing State facilities, the proposed storm water management plans shall be reviewed by the State Highway Administration following their approval by a county, a soil conservation district, or the State Water Resources Administration, or all of these. The State will review the proposed facilities based on the design-year storm of the existing State facilities. For example, State highway cross culvert outfalls will be analyzed using the functional classification storm, State side ditch outfalls on the 10-year storm, State longitudinal storm drain outfalls on the 25-year storm, etc.

(3) All work occurring within a critical area shall require a review and approval by the Critical Area Commission (CAC), and such approval shall be provided to the Administration before the work begins.

C. Information which is required to determine properly the effect of proposed drainage facilities on existing highway drainage facilities is as follows:

(1) A map showing the drainage areas contributing to the proposed drainage facilities and the drainage areas contributing to the existing highway drainage facilities which are affected. When photogrammetry coverage is available, these maps are the most desirable for presenting this information. When there is no photogrammetry available, U.S. Geological Survey Quadrangle Maps, if possible enlarged to at least a scale of 1 inch = 500 feet, are the next choice.

(2) Current zoning information, preferably presented in map form, covering the entire drainage areas involved.

(3) Grading plans, if the project is part of a residential or commercial development.

(4) Plans of the proposed drainage construction, identifying each pipe or other structure involved.

(5) A profile of the proposed drainage construction, extending sufficiently into the Administration right-of-way so that differences in survey data between Administration construction plans and the proposed improvement can be clearly established. When the existing drainage facilities are of considerable age, the profile should be extended to cover all affected facilities within the State Highway Administration right-of-way. Profiles of proposed storm drain systems should include inlet grate elevations and manhole cover elevations, in addition to invert elevations.

(6) Hydraulic calculations in accordance with currently accepted engineering practices.

D. If traffic conditions demand the modification of existing signals or other traffic control devices or the erection of new signals or other traffic control devices at private (commercial) access points, erection and maintenance are the responsibility of the permittee or other responsible parties. The State Highway Administration assumes no obligation, financial or otherwise, for erection or maintenance.

E. Entrance Approval. Administration approval of entrances should be obtained before finalizing the development plans and making application to the local authorities for a building permit.

F. Entrances onto highways can only function to the degree of efficiency that the interior traffic pattern permits. Therefore, in developing the site plan, every effort should be made to employ accepted traffic engineering principles in designating the interior traffic pattern.