NRCS-MA Tyler Dam Rehabilitation Project Floodwater Retarding Dam

Please see Tyler Dam Addendum No. 1 in the attachments/links section for further details and updates. Tyler Dam Rehabilitation Worchester County, MA Site Showing on: Wednesday, May 27?? at 10:00 AM at the site 200 Robin Hill Street Marlborough, MA 01752 The work consists of rehabilitating the existing dam to be in compliance with current safety and performance standards. Engineering studies identified that the dam has inadequate auxiliary spillway capacity that would result in overtopping and breaching of the embankment during the probable maximum flood. The major items of work include:

excavating the approach channel upstream of the auxiliary spillway drop structure by 2.5 feet to improve flow efficiency; installing a geosynthetic clay liner in the auxiliary spillway approach; raising portions of the dam embankment crest to provide additional freeboard and create a uniform crest elevation; constructing a concrete crest wall to provide freeboard and prevent overtopping at a low spot where Robin Hill Street intersects the top of dam; replacing concrete joint sealant above the waterline in the auxiliary spillway and in the principal spillway conduit; replacing existing chain-link fencing surrounding the auxiliary spillway drop structure; and removing trees within 20 feet of the right upstream embankment groin.