Reconnecting the rivers
Following the initial Wye survey in 1995 we were shocked to find that over half of all available spawning habitat for salmon and over three quarters of trout spawning habitat was blocked off through a combination of lack of thought and neglect. Weirs and crossing points had been built that created impassable barriers whilst huge debris dams had formed on the tributaries completely sealing off 100's of km of spawning and nursery habitat. For salmon this was disastrous and one of the main causes of the decline. For trout, whilst populations remained above the blockages the run of large main channel residents, which used to provide the bulk of the eggs deposited had been blocked off. This meant that the annual migration of surplus 10-15cm fish down to the main river no longer occurred, leading to a collapse in the trout fishery.
Between 1996 and 1997 the foundation embarked on an ambitious and challenging programme to reopen the tributaries. The experience of the Tweed and elsewhere has shown that this is the single most cost effective way of increasing fish populations. In total during these two years 518 debris dams and weirs were removed and 12 fish passes built on weirs or crossing points. This action reopened 132km of salmon and 330 km of trout spawning areas. The work was done by 2 people in 2 years after 30 years of inaction by the relevant authorities.
The lower weir on the Digedi before and after the Foundation built
a fish pass
After this initial effort the Foundation has continued in WHIP , pHish , UP! , Leader+ and Lugg & Arrow, Radnor to open up new areas and the current and historical situations are detailed on the maps below.
The map below shows the extent of the Wye catchment upstream
of Hay-on-Wye that was blocked to migrating fish in 1995.
Roll your mouse over it to see the situation in
2005.
Red: Access barred to migrating fish by weirs, timber blockages etc
Black: Areas of the catchment that are permanently blocked - natural waterfalls,
Elan Valley Dams etc.
. Site of weir, waterfall or fish pass.
Despite all this work it is sad to say that the two largest and potentially most productive Wye tributaries are still blocked off to migrating fish.
Staunton Weir on the Arrow and Osbaston Weir on the Monnow
The Lugg and its main tributary, the Arrow, have numerous barriers built by engineers in the latter half of last century to control flooding and erosion, most without adequate fish passage. The Monnow used to have three blocking weirs on it until recently. Nature has intervened to wash one away but the largest and lowest downstream, the Osbaston weir at Monmouth, remains.
The Foundation has been working closely with EAW to reopen these catchments, but without significant success so far. Both are included in the Agency's Salmon Action Plan. In 2003, the first fish pass on the Lugg was completed at Hampton Court allowing fish up the Arrow and middle Lugg and Arrow. The flood alleviation scheme weir at Leominster is the next obstacle and together with Osbaston weir, R Monnow, needs urgent attention.
In 2004 we turned our attention to the Usk and found that whilst the river above Brecon is mostly unobstructed, the catchment from Brecon to Abergavenny is as bad as we found on the Upper Wye in 1995 with every major tributary having at least one serious obstruction. These are being tackled in our current Usk project.
This map shows how much of the Usk system was blocked in July 2004
Roll your mouse over it to see the situation in
2005.
