Chichester Rocks

Posted on: September 18th, 2013 by Leslie_Zucker

Most of the large rocks need­ed to com­plete a stream restora­tion project in Chich­ester have been deliv­ered to the site. Although the col­or­ful “rock say­ings” paint­ed on the trucks can be amus­ing, res­i­dents may be hap­py to have few­er large trucks called “Dumpasaurus” trundling down Rt. 214. The rocks are being used to con­struct deflec­tor vanes, rock sills, and rock revet­ments in the Stony Clove Creek chan­nel. These struc­tures, com­bined with veg­e­ta­tion to be plant­ed at the site, are part of a design to sta­bi­lize the chan­nel and pre­vent ero­sion of hill­sides and back­yards. The Stony Clove Creek is a steep, moun­tain stream with a lot of pow­er to move large boul­ders. Accord­ing to the Ulster Coun­ty Soil and Water Con­ser­va­tion Dis­trict, the rocks being used at the site are sized to resist the high veloc­i­ty flows we have his­tor­i­cal­ly seen in Stony Clove Creek. The Creek through the project area con­tains a num­ber of large boul­ders and cob­ble that move dur­ing very high flows.  To help pre­vent the move­ment of rocks in designed struc­tures, the rocks are buried, stacked, and posi­tioned rel­a­tive to each oth­er. They are care­ful­ly placed at appro­pri­ate ele­va­tions to direct water over the struc­ture with­out cre­at­ing a bar­ri­er to fish passage.