NACA Sayers Meadow early days creating riffles

Sayers Restoration

Sayers Meadow Habitat Restoration Project

Since the 1960s many English rivers have declined as fisheries as a result of the pressure of modern day lifestyles. Agricultural land drainage practices, overworked sewage works discharges, over abstraction of water and increased run off from urban developments have all had an impact. While many of the once grossly polluted rivers in the countries industrial areas have been cleaned up considerably, many of those in more rural areas have declined significantly. Nowhere has this been more noticeable than with the rivers of Norfolk, the Wensum, Waveney and Bure in particular.

In 1988 Norfolk Anglers Conservation Association took on 1.5 miles of the River Wensum in Norfolk as an experiment to see what they could do to improve the fishery. The services of Dr Richard Hey and Richard Smith from the University of East Anglia (UEA) were commissioned, who by combining their knowledge of environmental river engineering and fish population dynamics, were instructed to provide a practical plan to improve the habitat diversity of the river in order to increase it fish populations.

Richard Smith had undertaken a number of extensive surveys of non-tidal reaches of many Norfolk rivers which had convinced him that limited habitat was the primary problem behind their decline as fisheries. His research showed that some areas of the Wensum held good numbers of fish but others were almost barren while water quality remained consistently good.

His findings seemed to show that the main limiting factor was that dredging of these rivers in order to facilitate better land-drainage had removed most of the channels natural characteristics. Having been turned into little more than featureless drains, they were now generally uniform in depth and over-wide, which had reduced the diversity of viable habitats available to juvenile and adult fish. Combined with reduced flows, through water abstraction, this situation had also resulted in increased siltation of the channel, which had further reduced the diversity of these rivers ecology.

After surveying the river throughout the project site, the UEA team drew up a plan of habitat improvements for stage one of the project, along approximately 250 metres of the channel. The plan included the construction of two gravel riffles in areas that were sandy bottomed, shallow and over wide. The addition of these riffles would improve the fishery by providing the following functions:-

a) Increase both the quantity and variety of food forms available to the
fish ie. shrimps, caddis, crayfish, etc.

b) Add diversity to depth and flows by creating a higher elevation to the flow.

c) Direct and channel the flow to scour silt from the river bed.

d) Provide new spawning areas for fish.

Getting the riffle materials on site Below each riffle further work was also required to add variation to the channel. Below Riffle One a new pool was to be dredged out on a bend in the river to provide improved habitat for adult chub and barbel. This would increase the depth from 18 inches to around 6 foot. The waste material would be used to back fill the inside of the bend in order to pinch the flow and scour the pool.

Beside each riffle cattle drinks were to be scooped out in the margins to provide summer habitat for fish fry. Being mostly fed by cold subterranean aquifers, chalk-stream rivers like the Wensum provide hostile environments for fry, however the sun warmed shallow water collecting in cattle drinks provides an ideal habitat for year one fry, providing them with sufficient warmth to grow and withstand the rigours of their first winter.

The plan was presented to NACA’s members and a limited number of permits were made available to our members on the basis that they undertook most of the physical work required to transform the fishery and also paid out of their own pockets for stock fish. Work started on the project in spring 1988. Willows and alders were planted, stiles and bridges were erected and construction began on riffle one by placing 40 tons of large flint rocks on the river bed and barrelling out 200 tons of smaller stones and gravel to lay over top of them. It was backbreaking work but within a year of the first riffles completion, a biological survey showed that the riffle had been colonised by a large variety of invertebrates, including native white claw crayfish and bullhead. Prior to its construction this location had contained only stone fly larvae. That year it also provided a major spawning site for chub and dace.

A second objective of the project was to establish a new population of barbel in the middle reaches of the Wensum several miles upstream of what was then Norfolk's only resident stock of barbel in the Costessey to Hellesdon reach of the river, an area that had been seriously affected by increased water abstraction. In December 1990, 1000 6 to 8 inch barbel were released into Sayers Meadow that we acquired from NRA Calverton Rd Fish Farm and this was followed by further stockings of 300 immature barbel in 1995, 200 in 1996, and 400 in 2001.

After finally completing Stage One of the project in 1992, the site had taken on a totally new appearance. The two riffles had considerably elevated the flow. They were alive with bullheads and stone loach and had also become major attractions to chub and dace residing in the fast water immediately downstream, waiting for food to be washed downstream. Even the odd brown trout had moved in. The new pool below riffle one quickly matured and became a major attraction to a large number of chub, particularly during the spring and summer. Each summer dense shoals of tiny roach fly colonised the new cattle drinks and all along the banks groups of recently planted willows and alders started to grow out over the water in strategically chosen places. The time had come to commission the UEA to draw up a second plan in order for us to improve a further 300 metres of the river, immediately upstream of the first stage of the project.

Permission had been granted for Stage One on the basis that the works undertaken would not impede flow during high river levels. This, in fact, proved to be the case and whenever the rivers flow and levels increased in response to rainfall, the floodwater could be seen to hurdle the riffles with no turbidity and no backup occurring. In October 1992 however, following a period of exceptionally heavy rainfall, flooding occurred throughout the valley, including some properties in the village directly upstream of the project site. The properties concerned had been built in the floodplain and the inability of the river channel to cope with the excess of water was due entirely to the old mill sluice/side-stream structure in the village.

Following this incident of flooding however the NRA declined to grant consent for us to proceed with Stage Two of the project unless we could prove that any further works would not lead to increasing the risk of flooding. Dr Hey's plans had taken these considerations into account nevertheless a long impasse existed for over two years before the project could move on. In 1995 Stage One of the project won an award from the Norfolk Society, the county branch of the Campaign for the Preservation of Rural England (CRPE), but even so, we were no closer to getting consent for Stage Two. Eventually following a series of meetings with the NRA an agreement was formed to commence new plans under the direction of Dr Nigel Holmes of Alconbury Environmental Consultants. At last Stage Two was moving again.

Shortly after this, the Environment Agency was established to replace the NRA and a more proactive relationship started to be formed between our two organisations. This included an offer of practical support, including funding and a commitment to undertake all the heavy engineering work. £900 additional funding was gained by NACA from the 'Shell Better Britain' award.

In December 96 Dr Holms' recommendations were drawn up, however it was not until Spring 99 that the work was finally completed. The completed work fell somewhat short of his original proposals however, due to the continued reluctance of the EA flood defence department. The main intention of the plan, however, being to restore three dredger-damaged pools was carried out and we were also able to narrow down the channel in these areas by installing hazel groynes to work as flow deflectors. A new dyke off of the river was dug out and widened to act as a fry refuge to provide shelter from winter floods and a number of new willows were planted along the riverbank. Also several hundred yards of riverbank were fenced off to prevent cattle trampling and grazing the banks.

In autumn of 2004, Stage Three of the project was undertaken. This included reworking the fry refuge to make it considerably wider and prevent reed encroachment from closing it over. Also two new pools were excavated to increase the amount of fast water pool habitat available for the increasing numbers of large barbel and chub now resident in this section of the river. Seventeen years after the projects conception, NACA’s Sayers Meadow Project is an ever-improving showpiece of what can be achieved with dedication, perseverance and a lot of hard work. Where the river once flowed sheepishly along a silted up, featureless dredger- damaged channel, today it has once again taken on the appearance of being a natural vibrant river. It's waters dance and clamber over polished riffles and flow mysteriously into deeper and shaded pools. Today the Sayers Meadow is home to a fine head of specimen barbel that look like having the potential to threaten the national record in the next few years. Perhaps in the future we will look into extending the project area and construct the odd new riffle or pool, in the meantime the fishery requires regular ongoing maintenance with willows to be pruned, groynes to maintain and riffles to rake.

Following the success of the project NACA have now taken on a second and even more ambitious habitat restoration project on the Wensum at Costessey Point. A third project is also being planned for one of the rivers more ponded reaches with the intention of restoring its once suburb roach fishery. When NACA started work of this fishery it was intended to act as a blueprint for others to follow. Today it is the blueprint for an official EA River Wensum Fishery Action Plan, and has led the way for numerous river habitat improvements that are now being carried out on many of Norfolk’s dredger damaged rivers.