Barrages and Wetland Ecosystems: the Environmental and Economic Impacts.
Save the Ribble Campaign are local Ribbleside residents who are spearheading the opposition to the Riverworks Ribble barrage, and the proposal to build thousands of new houses and businesses on Ribbleside Green Belt and operational floodplain in Penwortham.
Here we will look at:
- why the Ribble is so important;
- what effects these proposals will have on its environmental integrity;
- the economic impact;
and take a detailed look at
- the example set by the Cardiff Bay Barrage.
We will also address the global significance of the Ribble Wetland in terms of issues of Sustainable Development through a link to one of our sister blogs, The Ribble Cycle Diaries, and thus why the Ribble Coast & Wetlands Regional Park rather than a Ribble barrage and Green Belt development is the only viable option for the future.
WHY THE RIBBLE IS SO IMPORTANT:
The Ribble Estuary is legally protected under UK, EU, and International law, due to its environmental significance to wildlife on an International scale. It is a Special Protection Area (SPA) under the Conservation (Habitats &c) Regs 1994, and the EU Birds Directive 1979, a Site of Special Scientific Interest (SSSI), a Biological Heritage Site (BHS), and a Ramsar Site (Ramsar International Wetland Convention 1971).
It is worth noting that the Internationally-significant numbers of individual bird species the Ribble supports, alone award the Ribble its SPA status 16 times over – it’s THAT important.
The Ribble is also protected along its length as a Biological Heritage Site, and it is also the pilot UK River for the EU Water Framework Directive.
According to the Environment Agency, the presence of a barrage structure across a main water body automatically places it at high risk of not achieving the EU WaterFramework objectives.
RIBBLE FLOODPLAIN AND GREEN BELT:
River floodplains are important to local communities, local wildlife, and the integrity of our wetland ecosystems, which is why the Environment Agency are strongly opposed to further developments on these vital areas.
Green Belt has its own protections from building development due to its vital importance to our native and migratory wildlife, and to our quality of life, and because this precious resource is being steadily depleted year after year.
Our woodlandand farmland birds have declined by 50% on average over the last few decades – some species by as much as 95%.
The Ribble’s Green Belt areas are especially precious then, as they contribute to our countryside wildlife habitats, our floodplain provision, and the integrity of our Internationally important River ecosystem. They are also, of course, aesthetically beautiful.
RIVERWORKS’ BARRAGE AND “Central Park” BUILDING DEVELOPMENTS:
The Ribble barrage and floodplain development proposals will damage this Nationally and Internationally protected wetland in two crucial ways:
1). A barrage would interfere with the free-flow of fresh and salt waters, silts and nutrients, which the tidal movements and downriver flows of the Ribble basin produce to replenish the inter-tidal mudflats and saltmarsh twice a day, every day, as it has done for thousands of years;
2). Building on the floodplain and Green Belt would remove this area from the Ribble’s operational floodplain, and remove most of this area from Green Belt provision, thus would deplete the integrity of the Ribble’s dynamic ecosystem on two key levels.
It is clear that both of these proposals run counter to Legal, Governmental, and local Planning criteria. The Legal protection of the Ribble under the Conservation Regulations 1994 alone deems that any development which even may impact on the Ribble’s SPA can not go ahead unless there is ‘no alternative’ – which clearly there is.
It is also clear that both of these proposals are neither environmentally nor economically sustainable.
Read the Environment Agency’s and Natural England’s statement of concern regarding the proposed Severn barrage as an example of their understanding of the damage barrages cause.
Riverworks initial claims are that ‘preliminary indications’ suggest ‘the likely capital cost of constructing the barrage ranges between £16m and £60m’ (Riverworks 01: Quality Riverside).
Hmmm… not only are these figures enormously different – one being a cool £44 million larger than the other!! – but there are no indications what these figures are based on, and as we know, estimates for ensuring large projects get the go-ahead are always wildly underestimated: see for example the new Wembley Stadium, the Millenium Dome, Britain’s bid vs actual costs for the next Olympics as a few pertinent examples... not to mention the Cardiff Barrage…
The Cardiff Bay Barrage was initially proposed at an estimated cost of £40million, which then became £113 million, but actually cost at least £200 million just to construct, and literally more than double this figure in real terms - £402 million - and to address the ongoing environmental impacts is costing well over £20 million EVERY YEAR, year after year, as will be discussed in detail below…
The other rather thorny issue for the Ribble Barrage is that Halcrow’s “Ribble Weir Appraisal”, commissioned by Preston Council the last time they thought of trying the barrage scheme out, has pointed out that there would need to be between two and four such structures anyway, due to the geological fall of the river bed between the Docks and the Tickled Trout opposite Brockholes... so we could easily be looking at least double if not quadruple their own estimate to between £32 million and £240 million before we even start to address the inevitable underestimations…
… and we wouldn’t mind betting that even Riverwork’s own larger estimate does not include re-routeing the dozens of streams, drains and culverts in Preston and Penwortham alone which would have no-where to drain if the river is permanently high, or building (let alone running) the pumping stations, water quality assessment mechanisms, waste treatment measures, the MASSIVE Environmental mitigation schemes that would be LEGALLY necessary to try to offset the damage caused, not to mention the staff, consultation costs, and resources needed to operate all these schemes…
As an example, we’ll take a tour of the Cardiff Bay Barrage, and the Environmental and Economic Impacts, and look at the numbers which just don’t add up.
Entrance to the Cardiff Bay Barrage
CARDIFF BAY BARRAGE:
The idea of building a barrage across the Taff Estuary (Cardiff Bay), and turning the once-magnificent Bay of Tigers into a picture-postcard boating lake was first suggested in 1987 by the then Welsh Secretary, Nicholas Edwards. His ‘whim’ to “prettify” Cardiff by permanently covering its “unsightly” tidal mudflats (yes, that ignorant dismissal of the life-blood of an inter-tidal ecosystem again) – also one of Britain’s important inter-tidal habitats for over-wintering birds (over 8,000 in number) including several protected species of wading birds - produced what must be one of the most costly ideas in recent British history, in environmental, economic, and sustainable development terms.
The concerns about the Barrage proposal raised by local residents, the RSPB, a number of Environmental experts, and the Environment Agency, amongst others, were ignored yet unfortunately proved to be well-founded.
Local resident Sian Best has published an excellent exposé of the Cardiff Barrage scheme in which the Barrage is revealed as ‘the outcome of a secretive and ill-informed sequence of political decisions of uncertain purpose… which now, and for the foreseeable future, leeches money from the Welsh economy, without any discernible public benefit and with much potential for public harm’ (A Whim Set in Concrete 2004, Seren Books, p.11).
The implications for local democracy are also staggering, with the barrage proposers in the local Councils, development companies, and Whitehall, ensuring commercial interests came first, riding rough-shod over local residents’ needs or wishes, local councillors who saw the other alternatives for "regeneration" and defied the Party line to represent the best interests of their electorate, environmental protection and assessments, and even involved ‘changes… made to the conservation status of the Bay in the [local] Structure Plan… to ease the Barrage… progress’ (Best 144, and 88).
Local Residents? What do they know?
Local residents in Cardiff opposed the Barrage because of the environmental damage it would cause to a protected inter-tidal habitat, the increased floodrisk it would bring to their homes, and the massive and unjustifiable expense of the project.
Their fears that impounding the Rivers Taff and Ely behind a tidal barrage would damage the inter-tidal habitat of the SSSI-registered Bay and therefore a substantial part of the Severn Estuary SPA (of which Cardiff Bay forms a part), and would lead to increased floodrisk to their homes, were dismissed in favour of the ‘enormous economic benefits’ it was perceived a barrage would bring, and anything between 11,000 and 30,000 new jobs promised…
It turns out that local residents’ concerns were more than justified, and that any economic “benefits” have been more than compensated for by the enormous economic drain the barrage continues to prove, year after year after year…
To try to avoid the thorny issue of the inevitable environmental impact the barrage would cause, the proposers of the barrage quickly turned the argument into a birds vs human debate (from jobs and urban regeneration and redevelopment and economic benefits, to flood defences – sound familiar?), which was a nonsense from the start: local residents were not opposed to redeveloping the Cardiff Docks area, but argued that a barrage was not necessary for this redevelopment to take place, and that making more of the fantastic wildlife of the Bay – which had the greatest tide range in Europe as well as huge flocks of wading birds - would be an asset!
The alternatives to a barrage were never considered by the barrage proposers, despite much work by environmentally-responsible architect Professor Chris Baines, local residents, environmental impact assessments and the RSPB (Best 70-79), who could all clearly see the enormous benefits for wildlife, local people, and tourism that a natural inter-tidal Bay would bring. Subsequently, when asked what had attracted them to the redeveloped Docks area, not one of the new or relocated businesses cited the barrage as the reason they moved to the area (Best 29).
The “new jobs” promise turned out a tad whimsical too… initial promises appeared to be plucked out of the air: 11,000 new jobs became 20,000 then ‘almost 30,000 jobs’ (Best 59, & 63) depending on who was speaking, and after a loss of approximately 15,000 existing jobs amongst local people (businesses cleared wholesale to make way for the shiny new Docks developments), and with many of the new jobs filled by the workers that the new businesses which moved in brought with them, the net gain of the 16,750 new jobs quoted as an actual final figure by the Cardiff Harbour Authority is nearer 2,000, so only a fraction of the new jobs promised have actually materialised. Even if the 16,000 figure IS nearer the mark, it is still half the figure of 30,000 often quoted, showing the economic figures were rather loose, to say the least.
Economic benefits, or an obscene drain on resources?
Estimates of how much the Barrage would cost ranged from £40 million initially, to £113 million for its later incarnation, but the actual cost – for construction alone - on completion in 2000 was £200 million… (see Best 8), with ‘the total cost’ estimated in 1989 ‘to be some £402 million’ (Ian Grist, Under Secretary of State for Wales, 1989, quoted Best 107) – and that was before it was actually completed, and before the costly remedial works had to be done to the inadequate sluice gate system in 2000-2001, on the insistence of the EA... not to mention the urgent dredging of impounded silts…
Then there’s the annual running costs for the barrage, which three years ago were costing the Welsh Assembly £21.4 million (see Best 8) per year, while the cost of the “replacement” habitat at Gwent Levels rose from £5.7 million in 1995 to £10.4 million in 2000 (yet has proven largely ineffective for crucial bird species displaced by the barrage)…
Then there’s the Environment Agency’s own annual economic expenditure on assessing and trying to redress the Environmental Impacts of the barrage…
So far then, a conservative estimate – given that the figures mentioned here are only some of the costs involved as many of the works we know have taken place we do not have figures for – appear to place the total costs so far to be £402 million to 1989, plus at least £20 million every year since the barrage was “completed” in 2000, meaning another £120 million to 2006, so a running total of £522 million and climbing by over £20 million every year -
- not counting the Environment Agency’s own expenditure, or the substantial remedial works the Cardiff authorities had to undertake to render the barrage fully operational; or the algal scum-scooping boats; rubbish clearance; midge, rodent and pollution issues; aeration system and oxygenation back-up vessels…
Environmental Impacts and the Net Losses to Wildlife:
The Cardiff Barrage was originally muted as a much smaller structure, further upriver than the barrage was finally built and therefore not originally intended to cover the inter-tidal area itself, and was proposed as part of a new road crossing across the River Taff.
A report into the potential environmental impacts on the wildlife of this initial barrage site, further upriver than the Estuary, found that the levels of disturbance to the birds on ‘this small but important SSSI’ would ‘increase’, and recommended the Taff Estuary be designated a Local Nature Reserve as this would ‘leave the birds undisturbed and provide a very valuable local amenity… [which] would amply repay all efforts made to conserve it’.
SSSI status (Site of Special Scientific Interest) means a site is entitled to protection from damage or destruction, and Dr. Peter Ferns, the author of the report, clearly recognised the damage the original upriver barrage proposal would cause to the downstream inter-tidal mudflats, as well as recognising the benefits to wildlife, local amenity value, and the local economy that preserving the Bay’s inter-tidal mudflats as a Nature Reserve and tourist attraction would bring.
But instead of listening to environmental assessments and residents’ concerns and forgetting about the barrage part of the development proposals for the area, the local Councils decided to put the barrage across the mouth of the Estuary itself and consequently drown the whole site.
A few questions leap to mind…
What is the value of commissioning environmental impact assessments if you intend to ignore them anyway? A Public Relations exercise…?
How can arguments purporting to the “economic necessity” of a barrage be justified when this costs so much more in monetary as well as environmental terms than the wildlife facility alternative would generate?
The Cardiff Barrage, then, has impounded a significant area of inter-tidal wetland which is now a fresh-water lake, and thus directly removed a valuable section of inter-tidal habitat from the Severn Estuary Special Protection Area (SPA)…
Environmental Impacts and the Economic Drain:
As a consequence of the barrage, the Cardiff authorities AND the Environment Agency have had to pay out - and continue to pay out - enormous sums of money to try to redress the environmental impacts. These measures have included – and continue to include - creating “alternative wildlife habitat” elsewhere; set up and run pumping stations to keep groundwater levels from rising too high and flooding homes; re-introduce 50,000 baby Salmon into the river every year, year on year; dredging; pest control; water quality problems in the artificial lake…
As a legal requirement, a 439ha (hectare) wetland was “created” on the Gwent Levels in an attempt to mitigate against the loss of inter-tidal wetland habitat on the Taff… this cost many millions, but unfortunately has proved to be largely a disaster for a number of wildlife species (Best 71-2;) – and, whilst the true impact will not be known for several years yet, both bird and fish species indeed appear to have suffered, Redshank, Dunlin, Oystercatcher and Shelduck apparently catastrophically, having all but disappeared from the area and not having relocated to the new site. A Study into these effects found the following:
A SUMMARY OF BTO MONITORING REPORT ON WADER BIRD MONITORING IN CARDIFF BAY.
The study concentrated on 5 key species (that is, most numerous) of over-wintering wader birds present in the Bay prior to impoundment: Shelduck, Oystercatcher, Dunlin, Curlew and Redshank.
Q: Were the numbers and distribution of birds within the Bay affected by construction work associated with the Barrage?
A: Initial work indicated that the overall numbers of over-wintering water birds supported in the Bay had declined prior to impoundment, perhaps due to changes in habitat quality. The distribution and behaviour of birds in the Bay were also affected by disturbance caused by Barrage construction.
Q: Were birds displaced by the Impoundment of the Bay and how did the water bird community change?
A: Prior to impoundment, the Bay supported a diverse water bird community, dominated by large (over-wintering) numbers of estuarine birds. Since impoundment a smaller community of birds has existed in the Bay. Only very small numbers of the 5 key species (Shelduck, Oystercatcher, Dunlin, Curlew and Redshank) have continued to use the Bay as a high tide roost site during winter, and only occasionally do individuals remain to forage at low tide.
Q: Were birds displaced from the Bay able to re-locate to other neighbouring sites?
A: There is evidence that 3 of the 5 key species (Shelduck, Oystercatcher and Curlew) displaced from Cardiff Bay settled at adjacent sites in the first winter following impoundment. However, these increases were not maintained and, with the exception of Curlew, there was no evidence that birds subsequently attempted to settle elsewhere. In the case of Dunlin, it was not possible to determine whether displaced birds were able to settle elsewhere due to an ongoing decline of the local population.
Q: Was there any impact on the condition and survival of birds that were forced to re-locate?
A: Most of the Redshank from the Bay were displaced to the Rhymney estuary. There is evidence that adult Redshank displaced from the Bay had difficulty in maintaining their body condition in the first winter following impoundment and suggested that the winter survival rate of Cardiff Bay Redshank fell after their displacement.
It is worth mentioning that the devastating impact the Cardiff Barrage has had on some species of wading bird is in the context of the 8,000 over-wintering birds Cardiff's inter-tidal mudflats used to support pre-barrage, therefore the concerns of the potential impact of the proposed Ribble barrage has to be viewed in the context of the 250,000 over-wintering birds the Ribble Estuary supports every year.
Fish species are another serious issue, and the monitoring of all fish species following the impounding of the Taff is ongoing.
That the Environment Agency are releasing ‘50,000 salmon smolts (baby fish) into the River Taff every year as presumed mitigation with respect to the construction of the barrage’ is very telling in terms of the impacts barrages are known to cause, even when designed with so-called fish passes.
The Environment Agency have had to commit large resources to try to mitigate against the Environmental Impacts of the Cardiff barrage (more details can be found here and at the end of this article).
The Cardiff Harbour Board’s Cardiff Bay Barrage “Environmental Report 2005-2006” raises the following issues, all of which also have to involve EA resources, as well as heavy economic input by the Cardiff Authorities – proud, it appears, of their ability to tackle the environmental problems the barrage is causing:.
‘The environmental conditions within the Bay and rivers [impounded behind the barrage] are favourable for the formation of large blooms of planktonic algae. Blooms can die forming scums on the surface of the water. Blue-green algal scums may contain toxins that could pose a risk to public health… [and are] both unsightly and giving rise to malodours as they decompose. Decaying blooms may also cause a breech in the oxygen standard’.
As a result, the Cardiff authorities have had to purchase special boats and equipment for removing these scums from the water surface… costing thousands to buy, staff to operate, and still leaving the water quality problems which cause the scums in the first place…and these toxic scums are then disposed of onto the Severn Estuary inter-tidal SSSI & SPA mudflats…
Bay level and flood defence:
‘Cardiff Bay barrage was designed to exclude estuarial water from the freshwater bay. The Severn estuary has a tidal range of up to 14 metres which means that at high tide the sea level can often be higher than the bay level which is normally maintained at 4.5 metres above Ordnance Datum… To exclude sea water the sluice gates are closed when the sea level is 30 centimetres below bay level on the ebb tide… during [which time] the combined flows of the rivers Taff and Ely are stored within the 200 hectare freshwater bay… in the event that river flow would result in an unacceptable rise in bay level… the bay level is lowered… to provide additional storage volume…’
To cut to the chase, the barrage has to have sluice gates, which are closed to prevent the tides coming in, but which can then, subject to river flow, increase floodrisk upstream of the barrage as the artificially-high water levels impounded by the barrage allow no extra capacity for extra river waters. To decrease this floodrisk, the impounded water has to be allowed to flow out into the estuary before the tide comes in, to allow greater storage capacity behind the barrage if predictions of river flow indicate high levels will occur during high tides…As it is, the EA had to insist that the original impounded water level be reduced from +8metres to +4metres AOD as the floodrisk was deemed too great.
Bizarrely, the importance of Cardiff Bay to wildlife is recognised in the Report, the monitoring of changes in biodiversity are recognised as necessary, and insists that ‘all new developments are assessed on their impact upon the natural environment, and planning guidance is provided to mitigate or compensate for any loss of habitat’ as part of the Cardiff Bay Barrage Act (1993) … the Act which ALLOWED the barrage to go ahead and thus destroying a significant area of SSSI-protected intertidal mudflats!!!
The “mitigation” against the destruction of the Cardiff Bay SSSI was the provision of wetland on the Gwent Levels – which is not only a different kind of biodiversity habitat to the one destroyed by the barrage, but the vast majority of displaced birds have not turned up there, showing that a natural inter-tidal ecosystem cannot be “compensated” for elsewhere.
‘when the weather is warm and there is little wind and rain, the dissolved oxygen levels in the deeper waters of the Bay will naturally drop. Low dissolved oxygen levels could significantly impact upon the fish, invertebrate and birds living in and off Cardiff Bay. The Cardiff Bay Barrage Act 1993 requires the dissolved oxygen levels to be at a minimum of 5mg/l in all places and all times. Cardiff Harbour Authority therefore uses an aeration system to mix the water thereby raising the dissolved oxygen levels… Additionally, if required, oxygen is added to the water using a mobile oxygenation vessel. Continuous real-time water quality monitoring and routine water quality sampling analysis facilitate the measurement of dissolved oxygen levels’.
In other words, barrage-impounded water = perpetual problems with water quality and consequential environmental risks, which means the perpetual necessity of having to re-oxygenate the water – particularly in warm weather, for three seasons of the year, but effectively needs to be monitored and redressed all year round: more equipment, staffing, time and money, of these perpetual environmental impacts.
To cut a long story short, the Severn estuary – like the Ribble – is a high-siltation estuary. As a result, the barrage has caused siltation problems and the new navigation areas have to be ‘dredged twice a year’ – very expensive, and also has its own environmental impacts. And all those tonnes of high-energy mud used to feed one of Britain’s best inter-tidal ecosystems when the Bay of Tigers was a natural, un-barraged estuary…
What happens upriver of the barrage is unclear… the Ribble is also a high siltation river upstream as a large proportion of its silts flow downstream to mix in with the sea-borne silts in the estuary. Barraging the Ribble would mean these silts back-up behind the barrage, reducing the riverbed volume and therefore increasing floodrisk as well as starving the estuarine mudflats of essential nutrients. As such, the Ribble would also need to be dredged on a regular basis – more expensive equipment, staff, time and money – and more environmental damage.
No fewer than 239 Groundwater monitoring locations have had to be set up, and regular rainfall, riverwater, and tidal monitoring has had to be implemented. So far 6 pumping stations have had to be constructed to try to offset the increased floodrisk to local communities. These have to be permanently operational. Groundwater has also to be analysed on a regular basis to check for deterioration in quality, which would affect the water quality – and thus the ecosystem – of the River Taff.
The Cardiff Harbour Authority are clearly pleased with their ‘state of the art fish pass’ (p7), but the Environment Agency have yet to determine how well this is working, and are already releasing 50,000 Salmon smolts (baby salmon) into the Taff to mitigate against the impact of the Barrage on the migratory fish. According to the Report, the long term target by 2005 is ‘1,000’ fish, with the figure ‘191’ inserted in the box… it is not clear what this represents, but the question arises whether this means that only 191 fish have been known to pass through, which appears woefully short of the 1,000 target figure… Read more about problems associated with Fish pass mechanisms here .
Other issues include measures necessary to cope with pollution incidents, the build up of debris and litter in the Bay (for which they have had to purchase specialised clean-up vessels) and the report mentions incidents of high river flow bringing large quantities of debris into the Bay which then have to be cleared, above and beyond the regular clean-ups required, invasive species of plant and marine life (many brought in on the hulls of boats and then left in the lake to reproduce), pests such as rodents and midges, the habitat and bank damage caused by the wakes of boats, discharge of marine toilets and oils and fuels from boats, saline intrusion, water quality monitoring and protection…
As Sian Best makes clear, local residents’ alternative vision of a sustainable living waterfront in Cardiff, involving a natural un-barraged river, would have cost less than a tenth of the obscene sums of money literally poured in to the barrage, money which could have actually ‘saved’ many ‘struggling communities’ in Wales but instead ‘would be frittered away on a concrete dam and a stagnant lake’ (90).
And Nicholas Edwards? Well, after retiring as a Government Minister, by some odd co-incidence, he and other barrage pushers landed themselves nice positions on the Boards of the largest landowner on Cardiff Docks… Associated British Ports and its subsidiary companies Grosvenor Square Properties Group PLC, and Grosvenor Waterside…. (see Best 31). We haven’t found a connection to the £multi-billion Grosvenor Estates corporation, member of Preston Vision Board…
Sustainable development is CRUCIAL for our environmental and economic present and future – and wetlands play a vital role in this. The Millenium Ecosystem Assessment states that ‘the net benefits from the more sustainably managed ecosystem are greater than those from the converted ecosystem when measurements include both marketed and nonmarketed services, even though the private (market) benefits would be greater from the converted ecosystem’ (p11).
This means that the more obvious commercial interests, and the economic benefits accrued as a result of converting ecosystems (by barraging an intertidal river or estuary, say) will be outweighed by the economic losses in the long term.
Ribble Coast & Wetlands Regional Park:
Preserving the Ribble as a dynamic inter-tidal wetland ecosystem provides a truly sustainable alternative vision for the present and future of the Ribble corridor, a vision which is sustainable in environmental and economic terms – and doesn’t involve changing the appearance or nature of the Ribble ecosystem, its Green Belt and Floodplain, but instead relies on its ecological importance to provide excellent amenities for local people and tourists alike…
It is estimated that by the Northwest Development Agency that new visitors to the Ribble Wetlands will generate £115 million EVERY YEAR, and bring 4,500 new jobs – and of course, will cost a lot less than a barrage to maintain!
Ribble inter-tdal mudflats at the confuence of the Douglas with the Ribble - one of the sites proposed for the barrage!
Natural, un-barraged inter-tidal wetlands on the Ribble - great for wildlife and great for people!
More details of Environment Agency involvement in the Cardiff Bay Barrage impacts can be found here, with some central points below.
All issues involve ongoing economic input, and the resolutions themselves also involve their own follow-up implications in the environmental and economic impact, such as dredging, the release of algal scums scooped from the Bay onto the Severn Estuary SPA, and so on… and it is clear that the EA have had to constantly press for the necessary measures to be addressed:
According to the Environment Agency:
‘The construction of the Cardiff Bay Barrage has meant there have been and will continue to be many issues requiring the active involvement of Environment Agency Wales. The Agency has a duty in particular to ensure that matters relating to water quality, flood defence and fisheries issues are properly addressed’.
The Environment Agency ‘has had to commit additional resources to ensure that these conditions are adequately complied with by setting up the Cardiff Bay Team that together tackle the wide-ranging environmental issues…’
Including ‘Floodrisk issues’: ‘sluice gate operation and the back-up system’; too-high water level at ‘+8mAOD’; ‘dredging’, and ‘operation of the bay maintained at a [lower] level of +4.5m AOD’; ‘a serious deficiency in the design of the electrical power distribution system’ forming ‘an unacceptable risk of failure to the operation of the sluice gates’ [which had to be remedied]; ‘Tidal flooding resulting from the leakage of lock gates at the… Graving Docks was common’; ‘Even with the Barrage’s ability to exclude high tides, defences of +8.0mAOD are necessary in the Bay area against fluvial events’…
‘Any barrage is potentially an obstruction to the passage of migratory fish.
‘Up to the time of construction of the Barrage, numbers of salmon and sea trout in the Rivers Taff and Ely were steadily recovering. To facilitate the passage of such fish, the Cardiff Bay Barrage includes a fish pass…. [but] Following impoundment, there were significant operational difficulties with both the mechanical features and the operating software. These have now been addressed by Cardiff Harbour Authority (CHA), however adjustments to the operating procedures and changes to mechanical equipment continue…. The fish pass efficiency is not known, however observations indicate that fish are using the pass though exact numbers cannot be determined.
... Statistics gathered from the pre-barrage construction fisheries monitoring programme will be compared to those post-construction to determine the nature and extent of any impact of the Barrage. These data will be used to determine the appropriate number of smolts (juvenile fish) to be released as mitigation. Some interim mitigation stocking of smolts into the River Taff has already begun’ . [ - in fact, the EA are releasing 50,000 baby Salmon (smolts) every year in expected mitigation – which indicates a serious effect on the fish stocks].
Monitoring Cardiff Bay Water Quality:
‘Studies have predicted that substantial algal blooms could occur in the freshwater lake throughout the spring, summer and autumn. Of particular concern is the predicted occurrence of toxic algae that can poison fish and other wildlife within the lake and also pose a threat to public health.
Due to the excessive algal growth predicted, Cardiff Bay has been designated as a Sensitive Area (Eutrophic) under the Urban Wastewater Treatment Directive. ‘Eutrophic’ means that levels of nutrients can affect the natural balance of plant life, including algae. Consequently, nutrient stripping at five sewage treatment works in the Taff and Ely catchments are included in the current Dŵr Cymru/Welsh Water investment programme.
It is hoped that the nutrient stripping will reduce the potential of algae forming in the Bay but the risk is not totally eliminated… algae disposal is via the Cardiff East long sea outfall into the Severn Estuary.
Groundwater: ‘As a consequence of Barrage construction, it was believed that groundwater levels would rise in certain areas of Cardiff. To counter this problem the groundwater is being pumped from a number of drains and wells. … The Agency has required that the quality of groundwater is monitored… Should the water be found to contain substances which could contaminate receiving waters, then the Agency would require that the water be appropriately treated and would determine formal discharge consents’.
Oxygenation: an ‘aeration system … was completed on the 11th May 2001. However… contingency measures [are needed] to support the existing aeration system in the event of a serious dissolved oxygen failure. CHA explored the application of hydrogen peroxide as a contingency measure to increase dissolved oxygen levels but following trials it was agreed that it would be discounted as a mitigation measure. After exploring a number of methods CHA found that the most effective way to support the existing aeration system would be a "bubbler" barge which they purchased in April 2004.’
Saline Intrusion into the Cardiff Bay Impoundment: ‘The intrusion of saltwater through the locking system from the estuary into the bay needs to be controlled, as it is a threat to the water quality of the freshwater lake… potentially creating a stratified layer below which water may stagnate’.
Other Issues: Invasions of Midges… ‘Cardiff Harbour Authority's trial use of a larval insecticide to reduce the problem... The toxicology of Bti [the larval insecticide] has been approved… Studies to determine the effectiveness of the larvicide trials are ongoing. There is no one method that will control midges effectively. The most effective control is likely to be the establishment of a stable and balanced ecosystem where competition and predation should prevent populations reaching the high densities so far observed.’
Dredging: ‘major dredging programme to improve boat access’; ‘ensure that adequate precautions were in place to protect water quality during the removal of the 600,000 m³ of fine silt... In addition to the main dredging works, several much smaller operations have since been completed in the inner harbour and within the graving docks’.
Waste Regulation; ‘algae’; ‘aquatic weeds, litter and debris washed down by the rivers... CHA are using a “water witch” vessel to collect the waterborne litter as well as arranging manual clearance along the bay edge. The Agency has ensured that all material is collected and disposed of safely in the most appropriate manner with waste management licences being determined as necessary’.
Find out about how the Cardiff Bay regeneration project planned to “re-unite the City of Cardiff with its waterfront” but succeeded in ruining an awe-inspiring wildlife habitat and tying itself and the Environment Agency into a perpetual economic drain.
Since this article was posted, one local resident, Mike, emailed us to point out the obvious floodrisk problem that the Ribble waters would present to a barrage given the enormous flows of water capable of coming down the Ribble (not to mention the Darwen and Douglas), coupled with the lack of a holding Bay/lake (see comments link below)...
...and to tell us about the disastrous situation that the Tees Barrage is causing to Salmon and other migratory fish, including another threatened species, Sea Trout. The Tees barrage is preventing fish from passing easily other than through the bottle-necks of the fish passes, and therefore the fish are presenting themselves as easy pickings to predators - including seals who have moved in for a permanent table at the Tees Barrage fast-food outlet:
Anglers Conservation Association solicitor Guy Lilley Allen, said: "The problem with the barrage is the salmon and sea trout are trying to run up the river, coming up to the barrage and are being delayed because they cannot find the very small opening of the fish pass and consequently seals are having an absolute feast."
See the BBC coverage of this here.
The gravity of the failure of the fish passes to perform adequately is discussed by a fisherman on his blog:
‘As early as October 2003, Environment Agency fisheries experts are on record as stating that "if further monitoring is carried out this is likely to show that the fish pass is totally inefficient." In December 2003, DEFRA stated that "neither British Waterways nor the Environment Agency appears to have been taking the problem on the Tees very seriously".
Two years ago, in 2004, DEFRA stated to the Environment Agency that "British Waterways appear to be continuing to avoid the key issue; that the fish barrage [sic] represents an unacceptable barrier to fish movements and the fish pass is not working effectively … it is disappointing that we appear to be no further forward in any assessment of whether the fish pass works effectively or not. Potentially yet another survey will only confirm anglers’ claims … that the fish pass is not effective. As a result we will then need to agree a new fish pass with yet another monitoring programme."’
See Martin James Fishing for more on this situation.
You can read more about this disastrous problem the Tees Barrage is causing for migratory salmon here.
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