Avoid crossing streams when possible.
- Cross at right angles at a point where the stream bed is straight and uniform.
- Minimize the use of equipment in the stream bed.
- Limit construction activity to periods of low or normal flow.
- Avoid prolonged activity in salmon streams during spawning periods (March 15-June 15 and July 15-Nov. 30).
- Minimize excavation and fill at stream crossings and other disturbances to stream banks and channels.
- Use materials that are clean, non-erodible and non-toxic.
- Avoid using soil as fill except when installing culverts.
- Avoid altering stream flow.
- Divert runoff from roads and trails leading to stream crossings into undisturbed vegetation. Avoid directing runoff directly into streams, including ephemeral streams.
- Construct bridge, culvert, or pole crossing at elevations higher than their road approach.
- If necessary, stabilize road and trail approaches to stream crossings with aggregate or other suitable material.
- Anchor one corner of bridge to prevent movement down stream.
- Stabilize exposed soil as soon as practicable.
- Maintain crossings in safe, functional condition.
- Close temporary crossings by removing culverts, poles, portable bridges and other obstructions as soon as crossings are no longer needed.
- Bridges are effective ways to keep equipment out of flowing streams.
- Utilize a bridge design that will provide safe access and minimize disturbance to the stream bank, channel, and the riparian management zone.
- Use temporary or portable bridges instead of culverts to access areas where permanent structures are not needed.
- Place them so as not to unduly constrict stream channels or impede flood waters.
- Anchor temporary bridges on one end with a cable or other device so they do not float away during high water.
- Install so they can be removed easily and promptly when they are no longer necessary.
- Portable bridges may be rented through the Indiana Division of Forestry. For more information, contact Jeff Settle at jsettle@DNR.in.gov or call 812-358-2160.
Consider using a permanent rather than a temporary culvert when the crossing is likely to be used again within 10 years. Avoid use if temporary or portable bridges are more suitable.
- Use minimum size of 12 inches in diameter and large enough to pass flood flows. See Culvert Size Guidelines.
- Use arch culverts where it is important to retain the natural stream bottom.
- Both ends should extend at least one foot beyond the edge of the fill material.
- Place in line with the natural stream course.
- Install at or slightly less than the natural stream slope.
- Compact fill material firmly around culverts, particularly around the bottom half to prevent water from seeping around the culvert.
- Cover the top of culverts with fill to a depth of 1/3 the pipe diameter or at least 12 inches, whichever is greater, to prevent crushing.
- Hollow logs are permissible in very small channels if they can handle anticipated stream flows but should be removed once they are no longer needed.
- Keep culvert open and free of obstructions.
- Use flared-end culverts or rip rap where necessary to protect culvert inlet from erosion.
Avoid using fords if practicable, especially in areas of high water quality concerns.
- Select fording sites with gentle approaches, low banks, and hard, stable streambeds.
- Construct to conform as closely as possible to the original streambed to minimize water flow restrictions.
- Stabilize the streambed and approaches where necessary.
- Stabilizing material may include: corduroy mats, reinforced concrete planks, crushed rock, rip-rap or rubber mats.
- Avoid depositing soil in the stream during ford construction and use.
- Avoid use during high water.
- Pole fords should be used carefully to maintain water flow.
- Pole fords are not appropriate for perennial stream crossings.
- Remove pole fords immediately after use.