The Middle Level of the low-lying Fens comprises over 120 miles of drainage channels of which 100 miles are statutory navigations. These navigations form the only link between the main UK canal system and the Great Ouse and there are over 1000 boat passages through the link annually. As the UK's fourth largest navigation authority the Middle Level Commissioners do a fine job in maintaining the navigations even though there is no boat registration scheme and they receive no income from boaters. EAWA campaigns to re-open the southern route through the Middle Level via the Forty Foot River/Horseway Lock and Welches Dam Lock which is at present sealed by an Environment Agency cofferdam. See our Project Hereward topic.