Each event yields a change in stage greater than 1.0 foot, change in volume greater than 70 CFS, duration more than 6 hours. This reach of the stream is analogous to an eastbound highway where we know the number of cars passing Point A heading east and passing Point B further to the east. There is only one stoplight in between, although no cars can turn. Thus, any inverse relationship between the gages must be due to a change in streamflow at RMD Inflow at RG and outflow at CG are representative of the start and end points to such a system. Because a rating curve, relating stage to discharge, has not been determined at CG only stage has been reported, the volume of flow, discharge at inflow and outflow is not available.
Stage is the principal variable in determining discharge and is an excellent proxy for discharge.
At all stations a ratings table is used to determine streamflow solely from stage, after the rating curve has been established by determining cross-sectional area and velocity for each specific stage. Our continuity equation is thus not based on specific calculation of discharge but on trends in the hydrographic record. The Riverdale Impoundment generates a lag in flow response. All reservoirs, ignoring changing management, dampen the response of a stream to upstream flow fluctuations and increase the persistence of flow downstream, reducing anomalous low flow periods. This is a positive attribute of the Riverdale Impoundment.