Tidal Gate Passage
Tidal gates are often the first barrier that fish encounter on a river when moving in from the sea.
Although not typically found on large rivers, they are common on small tributaries of larger rivers, or small rivers that run directly to the see. Intended to stop land-ward inundation by saline water, they also prevent the upstream migration of fish, particularly juvenile eels, called ‘elvers’.
Fishtek have designed (and installed) several Tidal Gate Dampers (TGDs) around the UK in the past. A pair of sites where this fish passage solution was designed and subsequently installed are Hatherley and Horsebeare, tidal gate dampers that form the tidal limit to two small tributaries of the River Severn.
Fishtek designed and installed TGDs for each of the two sites and monitoring then showed that they increased the passage of elvers past the tidal gates by up to 90% – a great result for eel populations within these two tributaries as well as the wider Severn.