USGS Crest Gauge, Type C, Galvanized, 4ft

The Crest-Stage Gage is a device for obtaining the elevation of the flood crest of streams. The gage is widely used because it is simple, economical, reliable and easily installed. Many different types of crest-stage gages have been tested by the Geological Survey. The one found most satisfactory is a vertical piece of 2 inch galvanized pipe with a wood staff held in a fixed position with relation to a datum reference. The bottom cap has six intake holes located so as to keep the non-hydrostatic drawdown or superelevation inside the pipe to a minimum. Tests have shown this arrangement of intake holes to be effective with velocities up to 10 feet per second, and at angles up to 30 degrees with the direction of flow. The top cap contains one small vent hole.

The bottom cap contains regranulated cork. As the water rises inside the pipe the cork floats on its surface. When the water reaches its peak and starts to recede, the cork adheres to the staff inside the pipe, thereby retaining the crest stage of the flood. The gage height of a peak is obtained by measuring the interval on the staff between the reference point and the floodmark.

While the standard gage is 4 ft in length we also carry 6ft and 8ft lengths.

Type A:  Galvanized and used for mounting on a flat, vertical surface with brackets.

Type C:  Galvanized and used for mounting on top of a 2in steel pipe with threads driven in the ground

Type AP:  PVC and used for mounting on a flat, vertical surface with brackets.

Type CP:  PVC and used for mounting on top of a 2in pipe driven in the ground

801-185  Support Post, Type C, 24in

801-186  Support Post, Type C, 48in