Scattergraph

This scattergraph displays data from a flow monitor installed in a 21-in trunk sewer. During wet weather, backwater and surcharge conditions are observed in a distinct manner referred to as hydraulic hysteresis.

This scattergraph displays data from a flow monitor with a drifting velocity sensor.

Most flow monitoring data can be described by the Manning Equation using either the Design Method, the Lanfear-Coll Method, or the Stevens-Schutzbach Method.

The Design Method is a traditional use of the Manning Equation and requires information regarding the roughness coefficient (n) and the pipe slope (S).

The scattergraph depicted here reveals shifting debris that reduces the pipe capacity at this monitoring location.

Scattergraph data from a flow monitor installed just upstream from a CSO regulator where dry weather flows are funneled into a 54-in sewer but flow depth exceeding 28 inches is carried over a side weir.