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Weir background
In the Spring of 1998, Professor Richard N. Weisman of Lehigh's Civil Engineering department initiated a project involving stream flow monitoring. At this time, the Earth and Environmental Sciences Department needed a way to continuously monitor the hydrologic cycle in the area. Two Civil Engineering majors, Tim Miller and Alan Fornwalt, with the assistance of Professor Weisman, developed a system to monitor stream flow in the stream on the north side of South Mountain.
Site and cost analysis were done in order to determine the most cost
effective and efficient method for stream monitoring. A culvert that
runs under Upper Sayre Park Drive was chosen as a site for the project.
Compared with other culverts, this site was the least obstructed by sediments
and would require the least maintenance. The stream runs through
the three-foot diameter pipe and spills over to the lower bank. A
steel plate containing a V-notch was attached to the west end of
the culvert. An ultrasonic depth sensor was installed behind the
weir to measure the water level relative to a fixed point on top of the
pipe. An electronic data logger is enclosed in a steel box next to
the weir. This feature makes the data accessible to a portable laptop
computer for data retrieval. The electronic monitoring system records
data every 15 minutes and will hold 220 days worth of information at a
time. When the data is retrieved, all 220 days will be taken from
the data logger to the laptop. From this information, stream discharge
can be calculated.
Professor Richard N. Weisman of Lehigh's Civil Engineering Department
stands by weir in stream on South Mountain