Hampshire & Isle of Wight Wildlife Trust is hosting a free webinar on Enhancing Chalk Stream Habitats on Thursday 25 July 2024.
See here to register your place!
Whitewater Valley Conservation Society
Welcome to the Whitewater Valley Conservation Society
Hampshire & Isle of Wight Wildlife Trust is hosting a free webinar on Enhancing Chalk Stream Habitats on Thursday 25 July 2024.
See here to register your place!
The future constitution of the Whitewater Valley Conservation Society, as informed by the letter from the Chairman in advance of the Annual General Meeting of 3 December 2023, can be summarized as follows.
The Whitewater Valley Preservation Society was established in the late 1970s to combat proposals for dredging the River Whitewater for gravel. The Society has since been involved in various activities, centered around the conservation of the chalk stream and its valley.
By the early 2020s, the Society’s original constitution was deemed inadequate for current needs. It was a loose association without a legal entity, which brought limited structure, minimal presence, and potential personal risk to members due to increasing regulation and compliance requirements.
Establishment of Legal Entity: The absence of a legal entity made members jointly and severally liable for the Society’s actions. To mitigate this, the Committee sought legal advice to address the issue.
Achieving Charitable Status: The lack of a separate legal entity also meant the Society could not attain charitable status, which had financial benefits for both the Society and its members. Establishing charitable status was seen as a means to grant the Society more substance, authority, and credibility.
Following the advice from specialist solicitors, the Society formed a “Community Benefit Society” named the “Whitewater Valley Conservation Society”, which was registered with the Financial Conduct Authority. However, achieving charitable status also required confirmation from Her Majesty’s Revenue and Customs, which was granted after two years.
The transformation gained unanimous final support and approval, following a strong turnout for the vote, from the contributors at the AGM on 3 December 2023 at the Cross Barn, Odiham.
The new Whitewater Valley Conservation Society now operates as a separate legal entity with charitable status, having its own bank account and is set to continue the work of the former Whitewater Valley Preservation Society.
The Society commends the efforts of and thanks the Chairman, Candy Burnyeat, Andrew Soundy for legal oversight, and Hon Treasurer Rupert Wiggin for their roles in navigating the Society to its new status.
The Whitewater Valley Preservation Society (WVPS) expressed concerns when the development of 500 houses on a site in North East Hook, adjacent to the roundabout on the A30, was first considered by Hart District Council.
The main reason for our concerns was the fact that the entire site sits on a slope (the West side of the river valley) which exposes the river not only to run-off from construction but, once built and sold, problems with the sewage generated by the site, given the lie of the land.
During the construction phase, there were indeed incidents of pollution to the river, despite assurances from Hart, and now the entire sewage system is reliant upon pumping of effluent into tanks on the site when the Thames Water network cannot handle the flow.
Whilst touring various pumping stations susceptible to sewage discharge recorded on the Thames Water sewage discharge map, WVPS committee member John Fleming, visited Holt Lane. Here it was apparent that flooding was occurring in the field next to the River Whitewater. A Thames Water engineer informed Mr Fleming that builders on the Sainsbury’s site had damaged a sewage pipe carrying effluent to the storage tank on site. Thus putting all of the houses at risk of flooding with sewage effluent from the damaged pipeline.
The only solution available to Thames Water was to divert many tankers to the location of the damaged pipe, to collect the effluent and transport it to the Holt Lane storage tanks.
Holt Lane pumping station links into the system leading to Hartley Wintney treatment works, but at times of heavy rainfall, the system is overwhelmed and effluent must be stored until capacity is available.
Since Holt Lane is known to need tankers to avoid having to discharge into the river, in these heavy rainfall conditions, the problem at Hook will inevitably lead to discharge into the Whitewater.
WVPS Chairman, Candy Burnyeat, and Mr Fleming feel this is sufficiently important for members to be informed and to write to the new Chief Executives of Hart and the Environment Agency.
WVPS believes there should be a full investigation into and report on the damage caused to the river, and actions proposed to alleviate the environmental impact on its chalk stream ecology.
The working of the current system and its reliance on holding tanks, especially in view of the changing climate and therefore weather patterns, should be the subject of an urgent review. There is a need to increase the capacity of the wastewater system to Hartley Wintney, thereby removing the constant danger of effluent discharging into to River Whitewater.
The members of the Whitewater Valley Preservation Society are deeply saddened at the death of HM Queen Elizabeth II.
Our thoughts and prayers are with the members of the Royal Family at this sad time.
God save the King.
The Whitewater Valley Preservation Society has responded to a request for an Environmental Impact Assessment Scoping opinion in relation to development proposals of 32 hectares of agricultural land at Lodge Farm, North Warnborough (22/01347/EIA).
WVPS points to serious environmental impacts on the River Whitewater, a chalk stream which is already failing to achieve Good Ecological Status, including:
In addition WVPS points to the devastating visual impact in a currently open agricultural landscape, which is crossed by several public rights of way (footpaths) connecting the many surrounding Conservation Areas and Sites of Special Scientific Interest (SSSIs).
The application fails to mention the nationally recognised colonies or rare bat species located in the Greywell Tunnel, which use the River Whitewater and Basingstoke Canal for their navigation and feeding routes. The application therefore needs lighting to be considered in the scope of the environmental impact assessment.
WVPS has therefore requested that the scope of the Environmental Impact Assessment is extended to include surface water management, sewage and lighting.
The Angling Trust team was out hard at work on a Sunday in March, conserving the River Whitewater.
Just downstream of Greywell Mill, along the boardwalk, the team were building natural deflectors with spindles woven into wooden posts. This will help narrow this section of the river, creating faster flow and a deeper channel.
They will aid generation of reed beds for riverfly larvae and scour pools for trout and other fish in this precious chalkstream.
These natural structures will also help to reduce scour and erosion of the bank, caused by dog activity from digging and jumping in and out of the river.
You are invited to attend a Police BARN MEET for Hart Rural – this coming Thursday 3rd February at 6pm at Rotherwick Village Hall.
It’s aimed particularly at those involved in the rural economy, who are likely to be involved with / interested in, rural policing.
So landowners, gamekeepers, farmers, other rural businesses or interest groups – or anyone with horses – noting one of the key speakers is Rachael Terry, equine liaison.
Heckfield Parish Council is ‘supporting’ the event by booking the venue and helping to promote it. This event was originally booked for Highfield House in January, but a late change of date and time meant we also had to change venue – hence Rotherwick Village Hall.
The Police BARN MEET poster, together with one which has a bit more background are attached. barn meet-Rotherwick-3rd Feb-
If you are interested in attending, please if possible let the Clerk at Heckfield Parish Council know by email to [email protected].
20/031835/FUL Chosley Farm Solar Park, Bidden Road, North Warnborough
Whitewater Valley Preservation Society response
Introduction
The Whitewater Valley Preservation Society was formed in 1980 with the specific aim of fighting unacceptable development proposals which founder members felt posed a significant threat to the health of the valley and the river.
The Society has set itself the objective of trying to protect the Whitewater Valley and the river from its source at Bidden to its confluence with the Blackwater, representing approximately nine miles of chalk stream. We represent some 200 riparian owners, residents and supporters of the Valley.
WVPS Objection
The National Planning Policy Framework (NPPF) paragraph 170b requires the classification of the agricultural land to be considered. NPPF clearly identifies the unsuitability of agricultural land that is higher than 3b for the siting for a solar farm. The Agricultural Quality Survey shows that the Chosley Farm proposal is on high quality agricultural land, with 51% categorised as Grade 3a, the “best and most versatile” agricultural land, which should not be prioritised for this development. If one considers the situation from an ecosystems services and natural capital assessment this site will surely fail.
HLP32 policy NBE2 states clearly that any adverse impact upon landscape and scenic quality and visual amenity must guide any principles of development.
The following assessment identifies the true extent of the impact upon all of these issues and one must not forget that the pre application advice stated that landscape was the key to whether this application could be approved or refused.
The applicant incorrectly claims that the chosen site is ideal with its dome shape because they consider that gives the site limited visibility. Whereas landscape features, landscape character and visual affects are all detrimentally impacted as a result of choosing a site located only a few metres from the well-known signal station site The Firs.
As a consequence not only will the significance of the Firs be degraded by the proximity of 95.47 Ha of dark reflective material and superstructure together with 3m hedging. The applicant’s own material indicates the 360° angle from which the site will be viewed from adjacent roads, major and minor, footpaths and bridleways but ignores the fact that due to the topography of the site it is visible for miles around and sufficiently far afield to be easily visible from such villages as Greywell, South Warnborough, and Upton Grey.
The site is adjacent to the SSSI at Greywell Fen and the northern half of the site is contained within the upper slopes of the Whitewater Valley, in one of the few places along the length of the river where the valley is pronounced and a visible and important part of the landscape. The photographs in below demonstrate that the longer range views and the landscape character will all be afflicted and adversely affected by the presence of the dark reflective panels and the way that the long views beyond the valley will be hidden by the proposed high planting needed to obscure the view of the solar farm, which will change the character of the landscape. The photographs illustrate clearly that the attempt by the applicant to claim that the landscape around this site has already been degraded by the RAF station is inaccurate, which in fact is invisible apart from the odd aerial, whereas the urbanising effect of the proposed installation will utterly destroy this altogether rural landscape.
Landscape character
The main distinguishing features in the National Character Area profile are “the rolling elevated chalk arable downland has an open, exposed character that provides open skies and long-distance views” and in the Hart District Character Area assessment “typical chalk scenery with strongly rolling land forms, sooth hill tops and dry valleys. A dominance of intensive arable cultivation and weak hedgerow structure, shallower slopes at the edge of the chalk which creates a large-scale, predominantly open landscape with extensive views and a sense of exposure.”
The applicant claims the proposal would have a Neutral or Minor Beneficial impact on a landscape which is described as having weak hedgerow structure by planting very high hedges which will obscure the long views for which this landscape is recognised. There must be a question of confidence that a new chalk grassland can be achieved, given the proposed structures on site and management regime. Therefore the impact upon the landscape character must be regarded as Adverse.
Visual impact
A detailed assessment of the total visual effect upon the North Downs can only conclude a sufficiently adverse impact as to require, on its own, that the application be refused. Whilst the applicant claims to be able to turn Major and Moderate Adverse into Negligible Adverse or Neutral this is achieved by ignoring the 360° visual impact upon the landscape which will be viewed from the many roads, byways and public rights of way and in particular will impact upon the valley identified in the Hart District Landscape Assessment. Just downstream of the source at Bidden, the valley at Greywell is at its most discernible and should not be disrupted by the solid black and reflective insertion of 95.47 Ha of solar panels. Furthermore raising one’s eyes from the view across the valley (for example from many points in Greywell) the RAF station is nowhere to be seen, but the distant hills to the south reveal the extent of the long views and why the North Downs are so valued.
River Whitewater / Greywell Fen SSSI
The proposed site is in the Whitewater Valley running right up to the source of the river Whitewater at Bidden Farm. The River Whitewater is a rare and important chalkstream environment, one of only around 200 hundred chalk streams globally, which combined with its proximity to the Greywell Fen SSSI, makes the location particularly inappropriate.
Greywell Fen is Grade 1 SSSI (Nature Conservation Review, NCR site). The main part of the site consists of waterlogged alkaline peats, flanked by a chalk valley. It has large areas of grazed fen meadow and tall fen vegetation, including reed beds.
According to the findings of the Environment Agency, the River Whitewater is currently failing to meet ‘Good Ecological Status’ as required under the Water Framework Directive. This conclusion is supported by three years of Riverfly surveys commissioned by the Whitewater Valley Preservation Society, with Salmon & Trout Conservation.
Natural England considers that the application could have potential significant effects on the Greywell Fen SSSI, particularly through construction impacts (e.g. from dust, spillages, polluted runoff etc) and discharges to the protected fen, wetland and river habitats.
In order to mitigate these adverse effects and make the development acceptable, Natural England requires that a drainage design should be submitted and agreed with Hart District Council. This should include evidence to show that the proposals will ensure there will be no deterioration in water quality, or changes to water quantity, in discharges from the site. This has not been provided with the application.
Basingstoke Canal SSSI
The Basingstoke Canal, together with associated ‘flashes’ and heathland, is nationally important for aquatic plants and invertebrates. The transition from calcareous spring water to slightly acidic conditions produces an extremely diverse flora, containing approximately half (87) of Britain’s native aquatic higher plant species, including 5 nationally scarce species. The Basingstoke Canal is botanically the most species-rich aquatic system in England. Twenty-four species of dragonfly occur on the Canal and other insects, including two nationally rare (Red Data Book) species, are well represented. Two sections of the Basingstoke Canal are of SSSI status. The western section lies between Greywell in Hampshire and Hermitage Bridge in Surrey.
The relative lack of pollution in the canal and the variation in water chemistry throughout its length have given rise to a diversity of plant species and communities that has no parallel elsewhere in Britain. This together with a rich and varied invertebrate fauna makes Basingstoke now a waterway of exceptional value to nature conservation:
The canal is largely supplied by calcerous water from Springs situated at the junction of the chalk and Reading beds (clay) at Greywell. Due to a slight West-East gradient, which gives rise to a definitive water movement, the overall system is an analogous to a slow flowing River with initially alkaline water which gradually becomes more acidic and less charged with calcium. Such a combination is a rare feature in Britain.
The vegetation types reflect this gradual change in water chemistry. At Greywell the flora is typical of that of a nutrient-rich southern chalk stream.
Greywell Tunnel information board
The Greywell Tunnel is of huge ecological importance as a haven for bats. The blockage has created a cave like environment within the tunnel, a constant temperature around 10°C and a high humidity provide excellent conditions for hibernating bats.
During the winter months it supports the second largest hibernating population of Natterer’s bat in Europe. Five bat species have been recorded in hibernation within the tunnel – Natterer’s (Myotis nattereri), Daubenton’s (Myotis mystacinus), Whiskered (Myotis mystacinus) and Brown long-eared (Plecotus auratus).
Large congregations of bats have been recorded swarming at both East and West portals of the tunnel during the autumn months. This behaviour has been observed at other important bat hibernation sites and is believed to be associated with mating. It has been found that bats come to such sites from great distances – radius of 60km or more. The genetic mixing as a result of mating between individuals from over such a large area helps keep bat populations healthy. During swarming studies the rare Bechstein’s (Myotis bechsteinii) and Barbastelle (Barbastella barbastellus) bats have been recorded visiting Greywell tunnel.
Natural England have commented that there is particular potential for adverse effects on the Greywell Tunnel (Basingstoke Canal) SSSI as the development would potentially impact on commuting and foraging routes for bat species utilising the tunnel for roosting. This comment was made elsewhere (Natural England review[i] of evidence of the impact of solar farms on birds, bats and general ecology and the EIA screening for the solar farm at Long Sutton) – but not on this application, which is much nearer and in the same valley as the Basingstoke Canal at Greywell Tunnel.
The Biodiversity Net Gain report produced by Weddle Landscape Design is misleading as it refers only to the claimed biodiversity “net gain” calculated via Natural England’s much criticised algorithm[ii] on the site itself. As outlined above, the important SSSIs of Greywell Fen, Basingstoke Canal and the River Whitewater are where the biodiversity and ecological impacts of this proposal will be felt.
Flood Risk Assessment / Drainage strategy
The Flood and Water Management team of Hampshire County Council, as the Lead Local Flood Authority, points out that the application contains no information about the proposed impermeable areas, discharge rates and volumes, so it fails to describe the real impact of the development on surface water management and local flood risk.
The picture below shows the almost permanently present “pond” opposite Ford Farm, showing where surface water drains off the solar farm site across Bidden Road and flows into the River Whitewater at/near its source. The presence of a major surface water overland flow route crossing the site and the need to robustly assess this as part of any future planning application is noted in the EIA screening.
Natural England states that drainage from the site could lead to deterioration in water quality, changes to water quantity in discharges from the site. Given that both the River Whitewater and the Basingstoke Canal SSSIs are designated for their unique water quality and chemistry this implies that surface water discharge could impact on these protected features.
Archaeology
Chosley Farm is the site of an important Romano British archaeological site as identified by the below ground archaeological section of the submitted Heritage Desk Based Assessment. The assessment demonstrates that there are a number of archaeological sites within the application area and that the site has a high potential to contain as yet unrecorded archaeological sites for the prehistoric periods through to the Roman period.
The impacts of the development such as roads, compounds, fencing and service trenches will have an archaeological effect (para 4.19). The assessment suggests that a staged approach to the mitigation is appropriate from targeted preliminary survey to mitigation, including mitigation by avoidance (ie preservation insitu) (para 5.7 to 5.11).
Application Process & Content
Hart District Council, as the Local Planning Authority, decided that an EIA was not required for this development, whereas they have decided that an EIA is required for a very similar size and scale of proposed solar farm development nearby to the south side of RAF Odiham.
There are inconsistencies between the submissions of consultees and opinions on whether an EIA is required, detailed in the Appendix 2, concluding:
20/01658/EIA Chosley Farm, North Warnborough |
20/02632/EIA Ford Farm, Long Sutton |
|
Location | The site is not environmentally sensitive such that significant environmental impacts are anticipated. | The site is therefore considered to be environmentally sensitive such that significant environmental impacts cannot be ruled out. |
Types and Characteristics of the Potential Impacts | The characteristics of the proposed development are not such that significant environmental impacts are anticipated. | The characteristics of the potential impact, given the spatial extent of the development, the nature of the impact in visual terms, the certainty of the impact and the duration of the impact (a minimum of 40 years), are such that significant environmental impacts are anticipated. |
The Planning Design & Access Statement provided by the Applicant is incorrect in a number of ways, including:
This has a domino effect of errors and omissions on material impacts throughout the application and consultation, such that Natural England’s advice and the Applicant’s Landscape & Ecological Plan are incorrect and incomplete. These identify the Greywell Fen SSSI but fails to identify the Basingstoke Canal SSSI or the SSSIs that exist along the River Whitewater.
Summary
The landscape and visual impact, the ecological and water quality impact on SSSI protected sites and the archeological importance of the site combined provide reason to avoid irreversible land use change on this site.
For all of the reasons in the foregoing, WVPS wishes to register the strongest possible objection to this application and requests that it be refused.
The Whitewater Valley Preservation Society has submitted its latest response to amended information submitted by the potential developer of Chosley Farm Solar Park, Bidden Road, North Warnborough. Please find this here: Chosley Farm amendments objection.
[i] Natural England. Evidence review of the impact of solar farms on birds, bats and general ecology (NEER012) 1st edition – 9th March 2017 http://publications.naturalengland.org.uk/file/6000213410447360
[ii] https://www.endsreport.com/article/1675423/why-natural-englands-net-gain-calculator-may-struggle-accurately-value-nature
JBM Solar is proposing a photovoltaic solar farm on land at Bunkers Hill Farm. The proposal would cover approximately 200 acres of Grade 3b agricultural land and deliver up to 50MW renewable energy. The site runs alongside the River Whitewater, with solar panels for the next 35+ years. We encourage you to look at the developer’s website to see the location of this proposal, also shown on the map above.
This is one of four current proposals for large solar farms in the Whitewater Valley, and one of five in very close proximity in the vicinity of Hook, North-East Hampshire, all of similar size and capacity. Each of these three proposals is just below 50MW, because over that capacity, they would be designated as nationally significant infrastructure, which would require consent of the appropriate Secretary of State.
The Bunker’s Hill proposed development is located on a greenfield site, on the western valley sides of the Whitewater Valley, on gently undulating land.
As noted in Hart’s report on the EIA screening (20/01807/EIA) the site is within the Whitewater Valley Landscape Character Area. This proposal would introduce built development on a greenfield site over a significant area. The proposed development would change the visual appearance of the area and result in some impact upon the landscape.
Hart’s Landscape Character Assessment (1997) identifies the Whitewater Valley landscape character area as within the Open Arable Farmland landscape type. Hampshire’s Integrated Landscape character assessment (2010) classifies the site as falling within Lower Mosaic Open landscape type.
The site has a sloping topography and is part of the valley for the River Whitewater with varying degrees of visibility from Reading Road. There are three public rights of way (PRoW) that cross the site:
In particular, the Brenda Parker Way long distance route runs between Andover and Aldershot. This route connects Tylney Park with the river valley and West Green Conservation Area in the east.
Other footpaths provide circular routes from centres of population into and across the Whitewater Valley landscape.
The use and value of these routes increased dramatically in 2020-21 and has remained high with many residents now working from home.
Landscape impacts may be confined to the site, whilst visual impacts would be wider. Coverage of the site would be over a large area but at low level. These impacts would be reduced through the retention of landscape features such as trees and hedges, although any such mitigation measures would likely vary in effectiveness given seasonal changes in foliage.
Therefore it is important o fully assess impacts on landscape and visual amenity through a comprehensive Landscape and Visual Impact Assessment, particularly in relation to public views from the PRoWs.
Local communities value the recreational resource, which the river and valley provides. So it will be important that the Landscape and Visual Impact Assessment (LVIA) provides a comprehensive set of representative viewpoints. These include assessment of effects from other key features, such as heritage and nature conservation assets, particularly where they contribute to sense of place and special qualities of the river and landscape more widely.
The proposed development includes a number of features, which can give rise to landscape and visual effects, in addition to the photovoltaic arrays. Ancillary development, such as fencing and CCTV posts, can also have an urbanising influence on the landscape.
Deer fencing in an area heavily populated by deer and in a council named after the deer (Hart) is of particular concern.
The current proposed layout does not detail the position of inverters (other than the central inverter), CCTV poles, storage container(s), access arrangements, delivery station or the location of the construction compound.
We would expect the LVIA to consider the effects of all aspects of the proposed development. This includes during construction, operation and in relation to the potential for solar glare.
Local Plan Policy NBE2 – Landscape is relevant to the proposed application. It states that ‘development must respect and wherever possible enhance the special characteristics, value and visual amenity of the District’s landscapes. This should be done with reference to the Hart District Landscape Character Assessment, visual amenity and scenic quality of the landscape and other identified criteria.’
There is increased recognition of the value of landscapes in terms of Local Plan Policy, local communities (as reflected in the Hook Neighbourhood Plan) and National Planning Policy (Para 170). Given this, we request that the LVIA includes a detailed assessment of landscape value of the Whitewater Valley, which will be affected by the proposed development.
The Whitewater Valley Preservation Society submitted its WVPS comments re Bunkers Hill Solar Farm objection to Hart District Council on the full application for a solar Farm at Bunkers Hill, Rotherwick, Hook RG27 9DA.
Our analysis of the application revealed that the applicant has failed to meet the pre-application advice provided. The applicant failed to provide thorough, rigorous assessments of the effects on Landscape, Public Rights of Way (PRoW), Heritage Assets and Ecological impact.
The Society’s thorough reviews of the developer’s assessments reveals the true extent of damage that would be caused by this proposal. The reviews also demonstrate that the application fails to comply with Hart’s policy requirements and, therefore, fails to satisfy the basis on which the application could be approved.
In conclusion, the Society believes this development would have a significantly negative impact on the Whitewater Valley. The development would destroy the valued landscape and historic assets / environment of the Whitewater Valley. This development – if approved – would change the rural nature of the Whitewater Valley and adversely affect the enjoyment of its landscape by this and future generations.
The Society’s members believe passionately in the integrity of this beautiful section of the Valley. They are distraught at the damage that would be caused to this idyllic and characteristic lowland river valley by what would be an extremely industrial intrusion of the proposed solar farm and its accompanying paraphernalia.
It is on this basis that the Whitewater Valley Preservation Society objects to the application. We therefore trust that Hart will refuse this application.
Salmon & Trout Conservation has undertaken a three-year Riverfly Census on the Whitewater. Their analysis S&TC Whitewater Conclusions final has revealed that the river is in ecological crisis. The River Whitewater is a chalkstream, one of only about 200 in the world. The most significant water quality pressures are sediment, nutrient and chemical pressure.
The River Whitewater is currently failing to meet Good Ecological Status as required under the Water Framework Directive. The main pressures and reason for failure are physical habitat and barriers to fish passage. This means fish populations are prevented from moving freely through the river. Such barriers include mills, weirs and culverts. Physical barriers also impede sediment movement. They change flow, which can promote build up of fine silts. Such accumulation alters the natural river form which can impact the ecological status. Our survey shows evidence of this, with persistent sediment stress being indicated by the invertebrate community.
Land use surrounding the Whitewater shifts from predominantly arable to grassland along the river. Arable farming, especially when it is undertaken right up to the river’s edge, can contribute high quantities of excess fine sediment to a watercourse. Crop harvesting and ploughing leaves soil bare and vulnerable to washing off during rain events. Water friendly farming techniques such as cover crops, buffer strips and zero tillage (where feasible) would benefit the upper reaches of the Whitewater by reducing the sediment load.
Many chemicals, such as pesticides and herbicides used in arable agriculture, bind soil and are delivered to watercourses via sediment run-off. Chemical stress was indicated at nearly all sites. A seasonal chemical impact was exhibited by the invertebrate community. All failures of the proposed Water Framework Directive Species At Risk (SPEAR) standard for chemicals occurred in autumn.
Burrowing from signal crayfish can increase bank erosion and introduce greater sediment loads into the river. Therefore, it is important not to overlook this as a contributing factor to sediment stress in the Whitewater. Invasive North American signal crayfish (Pacifastacus leniusculus) were detected at all of the sites monitored in the Whitewater survey. These crayfish are capable of exerting change in ecological condition to the river both directly, through disease, predation, competition or displacement, and indirectly by disrupting food chain dynamics and altering physical and chemical habitat characteristics.
In 1981 mass mortality of the native white-clawed crayfish (Austropotamobius pallipes) was observed and following this, the species completely disappeared from the Whitewater and Loddon rivers. Crayfish plague, of which signals are carriers, is suspected as the cause but this is unconfirmed. Signal crayfish are found most frequently at Hook Mill. Juvenile signal crayfish recruitment was particularly high at Poland Mill in spring 2019. A lack of leeches and molluscs found at these sites infers an ecosystem impact from signal crayfish predation.
Taking appropriate measures to reduce the signal crayfish population may benefit the Whitewater’s ecology. Activities such as trapping will not eradicate populations of signal crayfish, but in some cases can increase the total number of individual macroinvertebrates.
Nutrient stress was less pronounced than sediment stress in the Whitewater at our surveyed sites, but was still indicated as moderate on many occasions. Excess phosphate entering the Whitewater is likely to be from a combination of sources, including runoff from arable agriculture and wastewater discharges.
The Odiham sewerage drainage area is served by the North Warnborough Sewage Pumping Station. This pumping station is reported to fail most years for a variety of reasons, including blockages, misconnections and groundwater ingress. Failure often results in the discharge of raw sewage directly into the Whitewater. Although our methodology evaluates longer term invertebrate community responses and not the biological impact of specific gross pollution incidents such as this, the failings of this system may have increased consequences for water quality in the future.
Applications for new housing developments in Odiham and North Warnborough have recently been made, but if developments were to go ahead, the sewerage demand in the area would increase. For any future development, it is essential that the sewerage infrastructure is sufficient to protect the environment. Thames Water stated that capacity to accommodate significant growth was not available in the North Warnborough area and that upgrades to the network should be anticipated.
Further investigations are being made to find out whether any improvements have been made at the North Warnborough SPS, as part of the most recent Asset Management Plan cycle.
During the survey two caseless caddis species relatively rare to the Whitewater system (according to historical Environment Agency records) were found. These were Metalype fragilis, found at Poland Mill and Polycentropus irroratus, found at Holdshott Farm.