I had a question from a field team regarding the locations of the downstream bankfull widths when a pool is present. Regardless of whether there is a downstream pool, you still take the bankfull widths directly downstream of the outlet, just outside of the structure (i.e. outside of wingwalls but within bank armoring if present). The only parameter that changes when a pool is present is the location of #80- "Downstream Channel Water Depth" on pages 48-49.
Rockingham Planning
May 22, 2019
Hello Everyone. At the training yesterday some people had expressed interest in seeing the text of our community notification letter. We keep a stack of these in our field vehicle and hand them out to members of the public when they inquire with our field crews. We found this beneficial to (1) provide them additional information and (2) avoid some of those long conversations we can get trapped in. ------------------------------------------------------------------------------ Memo To: RPC Commission Community Members and Municipal Officials and Staff From: Christian Matthews, Transportation/GIS Analyst, Rockingham Planning Commission Date: May 22, 2019 Subject: RPC Regional Stream Crossing Assessment Notification This summer and fall, Rockingham Planning Commission (RPC) is continuing a regional project aimed at identifying stream crossings (culverts and bridges) that may pose a hazard to our communities. This multi-year assessment of stream crossings in the region is intended to assist municipalities in identifying critical and hazardous culverts and bridges, particularly those susceptible to failure due to flooding or those that cut off critical evacuation routes. Using state stream crossing assessment protocol, RPC will have staff members out collecting data on state and local roads. The assessments will involve staff accessing crossings from public right of ways. The RPC shares all information collected with our member communities and works with those communities during the summer to help identify areas know to be problematic. Municipalities can use this information as a guide to prioritize those stream crossings most in need of retrofit or replacement. Along with prioritizing infrastructure modifications, results of these assessments can also be incorporated into municipal and regional hazard mitigation plans and vulnerability assessments. For more information about this project and to view this public data, please go to: http://www.rpc-nh.org/maps-and-data/data/transportation-asset-inventory-data For any questions or comments please contact Christian Matthews at (603) 658-0523 or cmatthews@rpc-nh.gov .
We had misinterpreted the protocol on this matter also, so thank you for the post! Perhaps it would be helpful to put a note about this in the next iteration of the protocol? We had looked to the diagram on page 48 (#79) where the "water depth - downstream channel" is labeled in a pool scenario, and then saw #80 notes the water depth - downstream channel to be "where the 1st downstream bankfull width is measured..." and so assumed the downstream bankfull widths started at the end of the pool in this way. A note in #80/81 specific to pools may do the trick I imagine.
Thanks!