Figure 12. Clear waters flowing over telescoping weir crest

ERDC TN-DOER-T3

January 2001

The telescoping weir is set within and attached to the base of a reaction frame that provides support

for it and the machinery that controls the telescoping movements of the weir. The telescoping weir is

raised and lowered via mechanical jackscrews that operate simultaneously either manually or by

solar/battery-powered motor. Technical specifications for the major telescoping weir components

of the weirs installed at Craney Island are described in Appendix I.

ADVANTAGES OF THE TELESCOPING WEIR: The innovative telescoping weir has numer-

ous advantages. The principal advantage is being able to provide an infinite adjustment of the weir

crest elevation (within the design height of the weir) and discharge velocities at the touch of a button.

The crest of the telescoping weir can be lowered easily to the bottom of the desiccation cracks in the

dredged material. This flexibility also provides efficient control of surface runoff, enhancement of

the desiccation and the drying processes, and some measure of mosquito control. The telescoping

weir reduces labor requirements and costs through the elimination of weir board handling, weir

board replacement, weir maintenance, and possible weir failure. The telescoping weir promotes

safer field operations, which is another significant advantage. It can be equipped with a variety of

sensors to measure effluent turbidity, temperature, pH, and oxygen levels. Most significantly, this

innovative technology provides a new standard for weirs used in confined placement areas for

dredged material that has been very difficult to improve upon for many years.