Water Cycle Study - East Devon District Council

Ref EWCS April 2010
Exeter and East Devon Water Cycle Study
flowing to the coast at Sidmouth, and the River Axe in the east flowing through Axminster to the
coast at Axmouth (just east of Seaton).
3.2.3 The Environment Agency’s Catchment Flood Management Plans for the Exe and the East Devon
catchments tabulate flows for a 1% annual probability flood event (having a 1 in 100 year chance of
occurrence) in the Exe, Otter and Axe catchments, as shown in Table 3.1 below.
3.2.4 The rivers respond rapidly to rainfall, particularly in the East Devon settlements and floods are
characterised by a very rapid rise and fall in water levels, with high flood peaks. Each subcatchment
contributes differently in terms of flow and timing in relation to the overall peak.
Table 3.1 – Estimated peak river flows for 1 in 100 year flood event (source: The Exe CFMP and
the East Devon CFMP, both Environment Agency)
River Peak flow (m 3/s) Volume of water passing in flood
event (m 3)
Exe (upper) 140 6 million
Exe total 750 60 million
Otter total 181 11 million
Axe total 152 10
20