Estuary detail

Below is an interactive map and a table of parameters derived through various sources – Nature Conservancy Council (Davidson et al, 1991), EMPHASYS (2000c), Dyer (2002) in Futurecoast, Townend (2005), ABPmer (2024) and ABPmer (2025). The data is indicative of recently determined bulk properties suitable for broadscale intercomparison of estuaries.

Alternatively take a look in the viewer.

Estuaries Database Viewer View in Estuaries Database Viewer
Estuary ID 67 
JNCC ID 149 
Name of estuary Erme Estuary 
Alternative name  
Grid reference SX625495  
WFD water body ID GB510804606100 
WFD water body name Erme 
MAGIC URL link MAGIC link 1 
Latitude 50.32593222 
Longitude -3.93775661 
JNCC classification Ria  
Updated classification Ria   read more on estuary classification..
Tidal classification Macrotidal  
Spring tidal range (m) 4.64  
Mean High Water Springs (mODN) 2.29 
Mean Low Water Springs (mODN) -2.35 
Mean Tide Level (mODN) 0.11 
Mean river flow (m3/s) 2.1 
Low river flow (m3/s) 0.55  
High river flow (m3/s) 4.41 
Name of furthest downstream flow gauge Ermington  
DEFRA Hydrology Gauge Data Explorer URL link DEFRA Hydrology Gauge link    
Area of basin (Ha) 144.7  
Intertidal area (Ha) 72  
Shoreline length (km) 17.1  
Channel length (km) 6  
Mouth width (m) 1100  
Valley width (m) 1100  
Volume at mean tide level (m3) 1500000  
Surface area at mean tide level (m2) 615000  
CSA at mean tide level (m2) 3768  
Volume at low water (m3) 419000  
Surface area at low water (m2) 296000  
CSA at low water (m2) 751 
Volume at high water (m3) 3350000 
Surface area at high water (m2) 1130000 
CSA at high water (m2) 6591 
Volume of tidal prism (m3) 2930000 
Dronkers' gamma (nondim) 1.15 
Storage volume over intertidal (m3) 1560000 
Channel volume to MTL (m3) 1790000 
Ratio of storage volume to channel volume (nondim) 0.87 
Hydraulic depth at MTL (m) 2.4 
DEFRA Catchment Data Explorer URL link DEFRA Catchment link   
Estuary template download link  

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Last Modified on: 20 June 2025
Printed from the Estuary Guide on 29/10/2026 02:18:34