Trails along stream banks and watercourses offer quintessential greenway experiences to users.
Furthermore, trail users highly value views of and the proximity to waterways. However, the variability of moving waterways can create challenging conditions and can, from time to time, lead to trail failures and maintenance issues.
- Stream/ hydrological analysis should be conducted prior to the design of a trail along a stream or river corridor. See Streams/ Rivers in Pre-Construction Evaluation.
- It is critical that trails are set adequate distances from erosive stream banks. (See plan diagram below).
- Stream banks with slopes of 3:1 or shallower are ideal for close placement of trail to top of bank. Steeper slopes will require stabilization in order to ensure a stable trail.
- The typical trailside shoulder should be provided.
- A 3’-0” min. planting buffer should be provided up to the top of the slope to slow runoff from trail and limit the need for mowing at the transition between the top of slope and stream bank.
- This typical cross section should also be applied where the trail is shelved into existing stream bank, below the top of the bank. Finished slopes should never exceed 3:1.
- Strip existing topsoil for reuse in finished grading.
- Minimize or avoid impacts to stream or streambank where possible.
- Design needs to consider flood clean-up activities and specific needs of maintenance partners.
Trail at Inside Bend
Trail at Outside Bend
- Trails should be placed much further away from outside bends in streams or waterways – 30’-0”minimum from top of slope where a stable (3:1 max.) or stabilized slope is present.
- On inside bends, the trail can be placed closer to the top of slope, 6’-0” minimum.
- If slopes are steeper than 3:1, stream stabilization techniques are to be utilized, or the trail should be set significantly further away from top of bank. This increased distance should be determined based on historical stream analysis or with the input of a stream specialist.
STANDARD CROSS SECTION
COMPONENTS: Click below for more information on each component.