DeRuyter Reservoir Outfall Abandonment

DeRuyter, New York

The Job

The DeRuyter Reservoir, in DeRuyter, New York, is a 557 reservoir originally developed as part of the Erie Canal system.

As part of a dam upgrade project, the three parallel 22″ diameter, 300LF outfall pipes needed to be abandoned, along with a stone box culvert downstream of the valve chamber the pipes terminated into.

The Challenge

Each of the three pipes had been previously blind flanged by divers. Therefore, the only access was from the downstream end within the valve chamber. In order to vent the air displaced by the abandonment grout, vent or placement points needed to be installed just behind the upstream blind flanges, which were approximately 40′ below the water surface.

The Solution

CJGeo worked with the general contractor to design an internal venting system utilizing sacrificial placement pipes installed from the valve chamber. After each of the sacrificial grout pipes was installed, the downstream terminations were bulkheaded, with vent stubs.

CJGeo mobilized a cellular grouting crew, who placed 30lb/cuft cellular concrete through each of the sacrificial grout pipes, until grout returned to the bulkhead vents, confirming fill. The work was completed over two days onsite–the first day for the abandonment pipes and first lift in the box culvert, and the second day for a top off pour on the box culvert.

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