Rule G: Bridge And Culvert Crossings

1. Policy.

It is the policy of the Board of Managers to preserve the capacity of the present drainage systems to accommodate future needs.

2. Regulation.

No person may construct, improve, repair or alter the hydraulic characteristics of a bridge profile control or culvert structure on a creek, public ditch or major watercourse in the District, without first obtaining a permit from the District.

3. Criteria.

Crossings must:

• (a) Provide equivalent hydraulic capacity as existing condition.
• (b) Retain existing navigational capacity.
• (c) Not adversely affect water quality.
• (d) Represent the minimal impact solution to a specific need with respect to all other alternatives.
• (e) Allow for future erosion, scour, and sedimentation considerations.

4. Required Exhibits.

The following exhibits must accompany the permit application. One set, full size; two sets, reduced to maximum size of 11”x17”.

• (a) Construction details showing:
  • (1) Existing and proposed flow line (invert) elevations.
  • (2) End details with flared end sections, wingwalls and/or riprap (energy dissipaters).
  • (3) Size and description of structure.
  • (4) Emergency overflow elevation and route.
• (b) Construction schedule.
• (c) Narrative describing construction methods.
• (d) Erosion Control Plan.
• (e) Computations of watershed area, peak flow rates and elevations, and discussion of potential effects on water levels above and below the project area.

5. Exceptions.

• (a) Criteria 3(a) may be waived if the applicant can demonstrate with supporting hydrologic calculations:

  1) the need for an increase in discharge rate in order to provide for reasonable surface water management in the upstream area, and 2) that the downstream impacts of the increased discharge rate can be reasonably accommodated and will not exceed the existing rate at the municipal boundary.