mean river level

mean river level

[′mēn ′riv·ər ‚lev·əl]
(hydrology)
The average height of the surface of a river at any point for all stages of the tide over a 19-year period.
References in periodicals archive ?
Maybe it was because one plate upstream of the Telford Bridge showed the water at 17' 4" above the mean river level. There are plenty of us alive today who remember the bold claims that "the new flood walls will ensure this will never happen again".