Downtown detour ahead

Starting July 15, access to Amoskeag Bridge westbound will be from Canal Street only as crews repair water main.

MANCHESTER — For a span of roughly six weeks, West Salmon Street at Elm Street will be closed to traffic traveling west onto the Amoskeag Bridge.

The detour will be required to allow Manchester Water Works to repair an aging water main across the Merrimack River under the bridge superstructure.

From Monday, July 15, through Friday, Aug. 30, crews will be “slip-lining” — installing a smaller PVC plastic “carrier pipe” inside the larger main that hangs under the westbound lane of the bridge.

The existing 24-inch iron water main — about 900 feet long — was installed in 1969, and is now showing external corrosion at many of its expansion joints and couplings, Water Works officials said.

For the duration of the six-week project, West Salmon Street will be closed from Elm Street to the on-ramp from Canal St. going west.

Traffic from Elm Street headed for the bridge will be detoured to West Brook Street and down onto Canal Street, then north to the on-ramp to the bridge.