Overview and Background

The Dust Bowl experienced by the United States during 1930’s saw the establishment of the Soil Conservation Service (SCS) on April 27, 1935. The SCS was established as a permanent agency the US Department of Agriculture with a mission to conserve the nation’s soil and water resources.

With this mandate, researchers at the SCS began the investigation and development of a class of flumes suitable for use in measuring agricultural flows. The H Flume, so called because it was the eighth in a series of flumes investigated, combined the flow sensitivity of a narrow angle V-notch weir with the flat floor and self-cleaning properties of a flume.

The H series of flumes are more modified weirs than they are true flumes – with a V-shaped throat and no diverging / discharge section. The H Flume design allows a wider range of flows than any other flume type – providing low flow sensitivity as well as the ability to measure high flow rates. Applications such as edge-of-field runoff monitoring that have low average flows and substantially higher rain even flows are idea candidates for H Flumes.

The flat floor of the H Flumes means that it passes sediments and smaller debris fairly easily. However, smaller HS / H Flumes are generally not recommended for use on flows containing sanitary solids or larger debris as these can lodge in the narrow discharge of the flume.

Installing a 1.5 H flume for edge of field water quality monitoring.

Lesson Plan and Activity

INSTALLING THE FLUME
The flume should be set so that it's centered in the flow stream.

The floor of the flume should be set high enough so that the flume does not operate under submerged flow conditions.

The narrow opening of the flume must be set downstream.

The floor must be level from front-to-back and from side-to-side (using a level on the floor - not the top - of the flume)

The flume must be braced internally (plywood and lumber are typically used) during installation to ensure that distortion does not occur.

The flume must not float out of its intended final position during installation.

Open channel flow (non-full pipe) conditions must exist at all times.

Skills Learned

Waterflow
measurement
waterquality
water quality
bmps
water
flow
flowrate
flow rate

1.5ft H Flume