Riverfly census on the Whitewater

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.

Injured Cygnet in Whitewater meadows

We have received a report of an injured young cygnet, apparently swimming alone on a stretch of the River Whitewater within the Whitewater Meadows ‘Suitable Alternative Natural Greenspace’ (SANG) area.  It seems to be swimming awkwardly and has lost some feathers/down.  Neither the Cob nor the Pen adults were seen nearby.
This may have been attacked by another older swan.  Unfortunately, it’s that time of year when young get sent off into the wider world by the parents and older birds start vying for territories.  We understand that Hart Countryside Operations see this every year at Fleet Pond. Likewise it may have been attacked by a fox or flown into powerlines.
What to do if you see this or any other injured swan or cygnet?
If the bird can be located please contact the Swan lifeline emergency helpline is telephone: 01753 859397.
Please see also the Swan lifeline website: www.swanlifeline.org.uk

Public consultation on Bunkers Hill solar farm extended

We are delighted to report that the public consultation for Bunker’s Hill Solar Farm has been extended until Friday, 23rd October at 5pm.

The Chairman of the Whitewater Valley Preservation Society has received the following message from JBM Solar, the developer for the Bunker’s Hill Solar Farm:

“Due to public feedback during our current consultation period on the Bunker’s Hill Solar Farm, we have decided to extend the consultation by another 4 weeks until the 23 October.  We will also be distributing another flyer to those residents within 1.5km of the site with a question and answer leaflet responding to points raised to date and setting out the new public consultation period.”

Please do use this opportunity to respond with your views on the Bunker’s Hill Solar Farm proposal via the developer’s website .

Chalkstream Parliamentary Group

A new All Party Parliamentary Group (APPG) on Chalkstreams has been formed to consider the challenges facing chalkstreams specifically.

England is home to over 75% of the world’s chalkstreams, which make an unique contribution to global ecology.

As the River Whitewater is a chalkstream, we encourage you to tell your MP how important chalkstreams are and why they need their own bespoke range of protections.

Please write to your MP and ask them to join the APPG.  You can find and contact your MP here.

Greywell Fen phase 2

Update from the Greywell Hill Estate

Alaska Ecological Contracting finished their part in the restoration of the Fen, leaving a large area of bare mud and a considerable amount of felled alder and poplar. Since when most of the mud has turned green and a lot of wetland birds have enjoyed their summer here.

In the meantime, Estate forester, Tom Elpelt, had to sort very random quality alder and has moved most of the alder either to Down Farm for chipping or into a considerable pile for sale to a wholesale firewood merchant. There was a bit of a delay as Down Farm had run out of room for any more timber.

The Estate has now started on the next phase of the restoration which is to restore the fencing so that cattle can be grazed on the Fen under the management of Hampshire and Isle of Wight Wildlife Trust. In order to get the fencing in, the Estate is coppicing the overstood hazel running along the side of the bridle path (route 703) and will cut back some of the growth encroaching onto the footpath (fp6) adjacent to the Mill Head. The hazel is on very strong stools and will grow again.

There is a cleared piece of ground at the top of the Mill Head and this is to be included in the grazed area, so the fenceline will cross the footpath in two places. There will be two kissing gates in the fence line and these to a standard that can be accessed in a wheelchair.

The first priority is to get cattle grazing as soon as possible, so we are pressing on with getting the Fen fenced. This means that the poplar will probably not be shifted until ground conditions permit in 2021. The current thinking is that it will be chipped on site and moved in bulk trailers to Down Farm. This has two advantages, firstly that chipping is very noisy and the site is a good distance from the nearest house. Secondly, grain trailers will carry more timber in chipped form than a conventional timber trailer and crane and so there will be less tractor movements and wear on the track.

The prime tool in all the work is the Estate’s 8 tonne excavator, driven by Joe Elpelt, which is equipped with tree shears (like a large pair of scissors), post thumper and a cone splitter to break the poplar down to a size that a chipper can handle.

Greywell Fen restoration

Works at Greywell Fen

If you have walked up to Greywell Mill recently, you may have wondered what is happening on the area between the Broadwater and The Moors Nature Reserve (the Hampshire and Isle of Wight Wildlife Trust’s land). The simple answer is fen restoration.

The area is a Site of Special Scientific Interest (SSSI).  It was designated for its fen habitat and associated flora including marsh helleborine, marsh valerian and marsh fern.  Once, grazing and coppicing would keep it open.  However, in recent years it has become overgrown and dominated by alder, thus reducing its biodiversity.  The work will enable the fen to return to “favourable condition”.  As Spring progresses, we hope to see it come alive with wildflowers.

Defra accepted the whole Greywell Hill Estate land into its Higher Tier Stewardship Scheme at the start of 2020.  This is a bureaucratic environmental land management scheme for farms and forestry.  It includes incentives to carry out major works, which would not otherwise be considered by landowners.  Natural England’s officer is keen that the Fen is restored.  Especially as the Wildlife Trust has undertaken similar work on the adjacent land several years ago.   Alaska Ecological Contracting, the same contractors as used by the Trust, are carrying out the works and the Trust’s local warden is overseeing it.

The contractor is felling all the alder and poplar.  These will be moved off site when ground conditions allow.  The end use of the timber will probably be for biomass production and it will be processed locally if possible, to minimise the haulage.  Wetlands are extremely efficient at carbon sequestration.  We believe that the work should have a positive impact on water levels in the River Whitewater and help to prevent the drying out of fen habitat which would otherwise be a cause for concern.

The contractors will clear the site completely.  The site will revert to grass and reeds and will be lightly grazed to control the return of alders.  The Wildlife Trust will help to manage the site.

Published with the kind permission of James Malmesbury

Storm Dennis causes flooding

Video

Storm Dennis, coming hard on the heels of storm Ciara last weekend, has caused flooding around Mill Corner in North Warnborough.

Mill Corner is under water.  Sewage is coming up from the manholes.  The pumping station on Hook Road is an island in a sea of sewage.  The sewage is now over flowing into the River Whitewater, an important chalk stream, which is a site of special scientific interest (SSSI).

Field water is running across the road to North Warnborough Greens. The ford gauge is 44 cm.
Thames Water have been called and the Environment Agency notified.

WVPS Autumn Reception

The Chairman and Committee of the Whitewater Valley Preservation Society invite you to an Autumn Reception on Sunday 15th September 2019 at 12 noon.

Please note! The Venue is now changed to:
Whitewater Mill, Poland Lane, Odiham, RG29 1JL

This is one of two meetings of the Society per year, which are included as part of membership.

Drinks and canapés will be available.

Members: Please R.S.V.P. as indicated on your invitation or by email ContactUs(at)Whitewatervalley.org.uk

Non-Members: You are more than welcome to join us. Please R.S.V.P. by email to ContactUs(at)Whitewatervalley.org.uk