Muddy River Flood Risk Management & Environmental Restoration Project Phase 1 Construction Activities Next 90 Days

May 2014 General: The Muddy River Flood Risk Management & Environmental Restoration Phase 1 Construction Project is located in the footprint generally between the Riverway downstream to Avenue Louis Pasteur. The major project components involve the installation of a 10-foot by 24-foot box culvert under the Riverway roadway, the installation of 10-foot by 24-foot box culvert under the Brookline Avenue roadway, daylighting of the area between the Riverway and Brookline Avenue, and daylighting of the area between Brookline Avenue and Avenue Louis Pasteur. Daylighting is the removal of existing twin 72" culverts and excavation of the area to return the waterway to a natural state. This Notice is intended to identify the general construction activities that will be performed in the next 90 days. A figure that shows the existing conditions and the proposed improvements is at the end of this report. May 2014 through July 2014 Period:

• On 29 March 2014, we performed another traffic shift to change both vehicular and pedestrian traffic to continue installation of the arch culvert underneath Brookline Ave. This traffic shift maintained Brookline Avenue, between the Riverway Connector and Park Drive, as one-way only inbound traffic and shifted the four inbound lanes to the left. As part of the vehicular traffic shift, a new pedestrian walkway was constructed on the left side of the Brookline Avenue adjacent to the former Sears parking lot for pedestrian travel through the project area. The current traffic pattern in place can be seen in the figure shown below.

• Since the shift on the 29th, the contractor had been preparing the work area between Brookline Avenue and the Jug Handle for the sheet pile cofferdam installation. Once the sheet pile cofferdam was in place, they excavated within the sheeting to get to proper grades and have begun installation of the drilled shafts for the remainder of the Brookline Avenue precast culvert sections. The drilled shafts installation began on May 5th and three drilled shafts have been installed since that time. We expect the drilled shafts installation to continue through the month of May into June.

• Once the drilled shafts are installed, then we will move forward with the pile cap and the invert slab concrete placements. • In addition, as part of this phase of work, the contractor will also start construction of a diversion structure that will be used to divert

storm water flow from two large existing storm drains into the Brookline Avenue culvert . These storm drains currently run down Brookline Avenue and eventually empty into the Charles River. However, they will not fit over the culverts that are being installed without major roadway modifications. The permanent diversion structure will allow storm water flow to empty into the new Brookline Ave culvert. An 84” diversion pipe is required to temporarily divert the flow from the two large existing storm drains while the permanent diversion structure is built. The temporary 84” diversion pipe will be trenched across the Jug Handle to the Muddy River. The installation of the 84” diversion pipe across the Jug Handle will be done during off hours to limit impacts to vehicular traffic.

• At the end of this notice we have included some pictures that show the excavated site in preparation for the drilled shafts; the three installed drilled shafts; and drilled shaft equipment in action removing the inner casing from the hole. We thought folks would be interested in seeing the work occurring behind the fence.

• If you have any questions, require additional information or would like to be added to the Project Contact List, please email the project mailbox at MuddyRiver@usace.army.mil

TRAFFIC MANAGEMENT PLAN DURING THIRD PHASE OF BROOKLINE AVENUE CULVERT INSTALLATION

Area within the sheetpile cofferdam excavated to within required grades for the drilled shafts. Note the existing timber piles from demolished

buried foundations right in front of the sheeting.

Three installed drilled shafts (concrete placed and rebar cage with plywood tops) for the right (looking downstream) pile cap. Note the fourth drilled shaft in progress in the background.

Drilled shaft equipment keyed into the inner casing for removal as concrete is placed in the hole.