South Easton Pond Dam Water Control Plan – Newport RI

Photo 1Client: R.P. Iannuccillo & Sons Construction Co.
70 Calverly St.
Providence, RI
Completion Date: 2012
Total Project Value: $4,500,000

Relevant Project Features: 

  • Prepared the Cofferdam Submittals
  • Prepared the Water Control Plan

RT Group, Inc. (RTG) was retained by R. P. Iannuccillo and Sons Construction Company of Providence, Rhode Island (RPI) to prepare a Water Control Plan for the rehabilitation of an existing 3,400-foot-long earthen dam. The rehabilitation consisted of reconstructing the existing dam and installing Pre-Cast Articulating Concrete Blocks (ACBs). Two separate Water Control Plans were prepared, one for the upstream and one for the downstream side of the dam.

Photo 2The upstream plan consisted of “leap-frogging” 500-foot-long cofferdam cells while rehabilitation of the dam progressed. This allowed for the reuse of materials between cells and therefore helped to minimize costs.

This innovative design was accomplished by utilizing steel sheet piles working in conjunction with return walls constructed of aqua-barriers and jumbo-sandbags. The use of these materials allowed for the cofferdam cells to overlap onto the newly installed ACBs where sheet piles could not be installed.

The downstream plan consisted of a similar “leap-frogging” method utilizing only jumbo-sandbag walls which spanned the width of the channel that existed on the downstream slope of the dam.

Pumping rates were estimated by RTG for both the upstream and downstream cofferdams and sumps and pumps were designed to dewater the cofferdams.