Cilley Hill Dam Removal Study and Preliminary Design , Jericho , Vermont

2026-11-03

The purpose of this study is to determine the logistics , obstacles , costs , benefits , and disadvantages of removing the Cilley Hill Dam in Jericho , Vermont . With the exception of historic resource considerations , which will be dealt with in a separate study , this purpose can be accomplished through the following tasks . Task 1 : Data Collection The first task includes a desktop survey of existing data ( dam inspections , existing plans , flood damage information , available GIS mapping ), a field survey of the site and conditions , the mapping of invasive species at the site , an assessment of habitats present at the site ( ex . wetlands ), probing / sampling / testing of impounded sediments for contaminants ( metals , PAHs , and organic contaminants ), an estimate of impounded sediment volume , stream geomorphic assessment , structural / geotechnical / utilities assessments , and photo - rendering of post - dam removal conditions . Winooski NRCD and VNRC will coordinate with landowners to provide access to the site . Task 2 : Hydrology Calculations and Hydraulic Modeling The second task includes the estimation of river flows , river analysis ( RAS ) model setup , and RAS model validation . These models must show the hydrological impacts of the dam removal both up and downstream of the dam . The models must provide an assessment of how much river elevation will be lowered following the removal of the dam . The engineer will also conduct an inundation analysis using these models .

Vermont

2026-04-28