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 11 
JNCC ID 39 
Name of estuary Duddon Estuary 
Alternative name This estuary spans more than one WFD waterbody (one of them is coastal, Duddon Sands) 
Grid reference SD195775  
WFD water body ID GB531207411800,GB641211172000 
WFD water body name Duddon, Duddon Sands 
MAGIC URL link MAGIC link 1 
Latitude 54.186928 
Longitude -3.235103 
JNCC classification Coastal Plain  
Updated classification Spit Enclosed   read more on estuary classification..
Tidal classification Macrotidal  
Spring tidal range (m) 7.6  
Mean High Water Springs (mODN) 4.13 
Mean Low Water Springs (mODN) -3.47 
Mean Tide Level (mODN) 0.23 
Mean river flow (m3/s) 5.17 
Low river flow (m3/s) 1.53  
High river flow (m3/s) 11.07 
Name of furthest downstream flow gauge Duddon Hall  
DEFRA Hydrology Gauge Data Explorer URL link DEFRA Hydrology Gauge link    
Area of basin (Ha) 6091.8  
Intertidal area (Ha) 5056  
Shoreline length (km) 65.5  
Channel length (km) 22.6  
Mouth width (m) 5000  
Valley width (m) 7500  
Volume at mean tide level (m3) 27200000  
Surface area at mean tide level (m2) 19100000  
CSA at mean tide level (m2)  
Volume at low water (m3) 1240  
Surface area at low water (m2) 12400  
CSA at low water (m2)  
Volume at high water (m3) 144000000 
Surface area at high water (m2) 38500000 
CSA at high water (m2)  
Volume of tidal prism (m3) 144000000 
Dronkers' gamma (nondim) 0.45 
Storage volume over intertidal (m3) 144000000 
Channel volume to MTL (m3) 95500 
Ratio of storage volume to channel volume (nondim) 1508.13 
Hydraulic depth at MTL (m) 1.4 
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 01/11/2026 02:34:05