After receiving initial approval in August 2016, the Foundation finally got the go-ahead for the "Delivering the Nutrient Management Plan" (DNMP) partnership project in January 2018.

Supported by the European Regional Development Fund, Environment Agency and Welsh Water, the project is rather less to do with nutrients than originally planned*. After 23 revisions to the project bid, DNMP now has three main areas of action:

  • The Foundation will improve upstream and downstream fish access for salmon, trout and eels at 14 Lugg and Arrow weirs.
  • Herefordshire Wildlife Trust will improve the structure and biodiversity of Bodenham lake by re-profiling the bank in three areas and establishing reedbeds.
  • Welsh Water will stop clean water flowing into Rotherwas Sewage works from the Yazor aquifer. This will improve their ability to strip phosphate at the works, decreasing the levels of P in the Lower Wye by 3-7% and reducing the severity of algal blooms.

Project objectives for the Foundation

For the Foundation, the major element of this project is a "Larinier" fish pass at Ballsgate weir on the middle reaches of the Lugg. This will be the first pass of this style that the Foundation has built.

Although some fish species could use the existing baulk pass, they could only do so in certain water heights. This might not have been such a problem if Ballsgate was the only weir in the Lugg system. However, there are so many that the river is often likened to Grand National for migrating fish species. Also included in the project is one smaller upstream easement on the Lugg and another on the Back Brook, a tributary of the Arrow.

While the fish passes will help migrating salmon, trout and grayling (Lugg passes), we will also be helping upstream migration of the endangered European eel. The plan is to install 100 metres of eel brushes on 8 Lugg and Arrow weirs.

Ballsgate weir on the middle reaches of the Usk before the installation of the Larinier fish pass

Ballsgate weir with a CGI impression of the Larinier fish pass to be built in 2018

Downstream migration

But the project is not just about upstream migration of fish species. Understanding of the importance of weirs in downstream migration has been growing in recent years. Young salmon (smolts) on their way to sea and brown trout are reluctant to enter water less than 12cm deep. In low flows shallow sill weirs can be a complete barrier to downstream migration.

Fish that collect above weirs in such conditions suffer heavy losses, where they are an easy target for a host of predators. During dry springtimes, the time of year when the majority of trout and young salmon migrate, it has been shown to result in as much as 100% predation in catchments with lots of weirs.

Within the DNMP project, the Foundation will cut and secure suitable notches into twelve Lugg and Arrow weirs that have been identified as barriers to downstream migration.

The Foundation has been allocated £273,196 of the £1,225,000 combined budget for all the project's partners. With this we will deliver the actions above by 2020.

October 2018

Foundation staff constructing an eel pass on a river Arrow weir at EardislandEarly in the year we surveyed all Lugg and Arrow weirs to check whether or not they were likely to cause issues with downstream migration.

At four Arrow weirs identified as a potential problem, we increased the depth of the flow over the crest. In addition, we have constructed a "smolt notch" on another Arrow weir where lowering the crest was not possible.

This has eased downstream migration for juvenile salmon and trout of all ages plus other species.

We have also constructed new eel passes on two Arrow weirs and modified another.

The large Larinier fish pass at Ballsgate was due to be constructed in the summer of 2018. However, due to the complexities of this part of the project, this was postponed until 2019 with work beginning in July.

For the latest news on the Ballsgate fish pass, see here.

Work starts on the Ballsgate fish pass, July 2019

We are very grateful to our project funders, the European Regional Development Fund and our partners Dwr Cymru Welsh Water and Herefordshire Wildlife Trust.

* The main part of our original project was for farm advisory work but this was moved into another project leaving just the fish access work.