Report: Development Control 16.04.09: Part I - (07) 09 0163 Ful - Croxley Green Watercress Farm

7. 09/0163/FUL – Part Retrospective: Addition of watercress silt pits; proposed renewal and erection of boundary fence and gates, re-positioning of watercress processing plant and removal of asbestos cement and their replacement with timber housing for water pump Houses and processing plant at CROXLEY GREEN WATERCRESS FARM AND FISHERIES, ROUSEBARN LANE, CROXLEY GREEN, WD3 3GG for Mr David Chalmers

(DCES)

The application has been called to Committee by three Development Control Committee Councillors.

It should be noted that part of the site lies within the Administrative boundary of Watford Borough Council. Parts of the application are within Watford Borough Council.

1.Relevant Planning History

1.108/1640/FUL - Part Retrospective: Addition of watercress silt pits; proposed renewal of boundary fences and gate, re-positioning of processing plant including farm shop, new fishing club house, new farm workers accommodation, installation of solar panels and turbines, installation of water pump houses, installation of bio digesters and construction of paths for disabled access at Croxley Green Watercress Farm, Rousebarn Lane. Application Withdrawn February 2009.

1.2Watford Borough Council – 09/0075/FUL. Retrospective planning permission for the watercress silt pits; Renewal and erection of boundary fences and gates; Relocation of watercress processing plant, and Removal of asbestos cement and their replacement with timber housing for water pump houses and processing plant at Croxley Watercress Farm, Rousebarn Lane. Pending consideration.

2.Detailed Description of Proposed Development

2.1The site lies within the Metropolitan Green Belt and is identified as a local wildlife site in the Local Plan. The total area of the site is approximately 5 hectares. However the District Boundary with Watford dissects the site in south east to north west axis approximately 67 metres south of the Rousebarn Lane Bridge. It consists of watercress beds served by the River Gade, and a fishing lake used by Watford Piscatorials. An air raid shelter and fishing club house exist on the site. Until recently most of the site was overgrown. The owner of the site has undertaken works on the site by clearing vegetation, removing asbestos from the ground, installing silt filtration pits, creating an opening onto the Grand Union Canal and provision of a boat basin.

2.2Vehicular access to the site is achieved from Rousebarn Lane over a 3tonne weight restricted bridge over the Grand Union Canal. To the north of the site is a public footpath leading to Cassiobury Park through woodland in Watford Borough. The footpath follows the application site boundary to the north and east before heading in an easterly direction over a pedestrian bridge over the River Gade to Gade Avenue. To the south of the application site is the Metropolitan Railway Viaduct and beyond is Cassiobridge Marina. The Grand Union Canal to the west of the site generally runs parallel to the site. A British Waterways private mooring exists on the east side of the Canal. Approximately 7 canal boats can moor.

2.3 For that part of the site which lies within Three Rivers, the application submitted includes the following:

2.4 Renewal of boundary fence. As part of the submitted application, several options were suggested including either the erection of 3m high steel palisade fencing; 2m high steel palisade fencing; 2m welded mesh with razor wire top; 2m high chain link fencing with razor wire top and 1m high welded mesh fencing with razor wire top. Following the receipt of advice from the Crime Prevention Officer and the planning officer; the applicant proposes to erect 2m high weld mesh fence along the western, southern and eastern boundaries. Along the west boundary, the fence would be erected on land that is within the control of British Waterways. The applicant has served Notice on British Waterways and completed the appropriate Certificate for the purposes of the planning application.

2.5 The relocation of Watercress Pressure Plant is on land within Watford Borough. For information this is sited approximately 82 metres from the eastern edge of the canal and 57 metres south of Rousebarn Lane. It measures 16 metres in length by 7 metres in width. It has a ridged roof design standing 4.5 metres above ground level. The floor level of the building is raised above ground level by 0.6 metres in accordance with the requirements of the flood risk assessment. It would have a tanalised exterior wood cladding, wood grain PVCu double glazed windows and fascias, and a tiled roof. The roof would have 5 solar panels fitted.

2.6 Part retrospective permission is sought for the removal of asbestos cement and their replacement with timber for the water pump houses. For the site as a whole there are 7 pumps. One of the pump houses is located approximately 33 metres from the edge of the canal and approximately 82 metres south of Rousebarn Lane. The size of the pump houses remain the same. The walls and roofs are to be replaced with tanalised timber. The pump house contains a water pump, power system (leisure batteries and generator), water meter, UV water filter, mechanical filter, sampling centre, remote water analysis and localised farm materials.

2.7 Retrospective application for the addition of watercress silt pits. These are 6 metres wide, 3 metres deep below ground level with typical water level 1m below the ground level. The eastern silt trap is approximately 15 metres in length. This is closed. The western silt trap is approximately 44 metres in length and connects to the stream and canal. The silt traps are approximately 32 metres apart. The supporting information accompanying the application advises:

The quality of water entering rivers after watercress production can have serious effects upon aquatic habitats. It is essential therefore that proper water management measures are employed. The main potential problems arise from suspended solids and release of excess phosphorous and potassium from fertiliser use. Use of fertilisers should be minimised and consideration given to the use of reed beds to a wetland strip to strip out excess nutrients.

Before watercress production can begin after a period of dormancy there needs to be a harvest of the overgrown crop and a reduction in the silted level in the watercress beds. The silt comprises mainly rotting vegetation and trapped suspended materials derived from stream sourced feed water. This build up leads to sediment in the water discharging from the cress beds that must be controlled before being discharged.

New silt control measures are therefore being put in place to deal with suspended solids both during the restoration of the beds and subsequently when the watercress farm is fully operational.

When it is known that there will be a lot of sediment, e.g. when the vegetation and accumulated sediment are being cleared from an area of the silted-up beds, discharge will be to a fully enclosed silt pond (the eastern one). During normal operation, the water will discharge to the western silt trap which connects directly with the stream and canal. The water will be caused to drop its load of suspended solids by imposition of a torturous route through the silt trap.

When it is necessary to remove silt, the connection with the canal and stream will be closed and the accumulated sediment cleared by a dredging barge brought in from the canal. Initially the silt will be removed from the site for disposal but may later be used to assist with the landscaping of the site, provided it is of acceptable quality. The silt traps have already been constructed although the features promoting a tortuous route through the main silt trap have yet to be introduced.

The proposed treatment scheme has been discussed with the Environment Agency and British Waterways and is understood to be acceptable to both organisations.

2.8 Whilst the submitted drawings show the boat basin and crayfish fishing sites, these have not been applied for in the planning application.

2.9 In support of the application, the applicant has submitted a Design and Access Statement, Flood Risk Assessment, Landscaping Assessment, Contamination Report, Asbestos Removal Report, energy statement, sustainability statement.

3.Consultation

3.1.1Inland Water Association - the Herts Branch of the Inland Waterway Association cannot see that this will affect the canal infrastructure, therefore no objections.

3.1.2Thames Water – with regard to sewerage infrastructure, no objection. With regard to water supply this comes within the area supplied by Three Valleys Water.

3.1.3Croxley Green Parish Council – no objection.

3.1.4Herts Biological Records – the area proposed for development forms part of a County Wildlife Site – Cassiobury Park; a site supporting a mosaic of habitats including neutral to acid part marshy grasslands, calcareous spring springs supporting fen vegetation and feeding watercress beds, valley alder woodlands, scrub, tall herbs, plantation and parklands. All designated sites are environmental assets. The degree of protection given is appropriate to status according to their international, national or local importance. The maintenance and enhancement where appropriate of these assets is encouraged.

HBRC support the proposals for the site as this will restore an historic land use and create local jobs. The proposals also aim to retain and enhance the local biodiversity of the site and in furtherance of this aim, request conditions for Habitat Management Plan, Bats and trees, Birds and trees, and control of lighting.

Furthermore, HBRC suggest that to protect the integrity of the application site, the boundary should be secured by suitable fencing as soon as possible. Presently the wildlife site is suffering from fly-tipping and trespassing.

3.1.5Crime Prevention Officer – this site has been subjected to a number of recent crimes. To combat against intrusion on to the site, support the application to install perimeter fencing and would recommend the installation of security fencing and gating where appropriate around the perimeter of these grounds in an effort to reduce the risk of further offences. Because of the crime and disorder history on site, suggest the fencing be a minimum height of 2.4m. Suitable types of fencing for this location would be weld mesh or Xpamet as these are more aesthetically acceptable to the surrounding environment. This sort of fencing can be powder coated and the darker the colour, the less visible it is.

3.1.6Environment Agency - the preliminary risk assessment (PRA) has now been submitted and our objection can be removed. The proposed development will be acceptable only if planning conditions are imposed requiring the submission and subsequent agreement of further details, as set out below with regard to contamination, details set out in the risk assessment are complied with. A landscape management plan. Informatives are also suggested.

3.1.7British Waterways – potential concerns relate to being able to fully understand what is proposed in detail and where. This would cover the fencing facing the canal and the visual impact of this from the canal and towpath, the location of the relocated watercress plant and its potential visual impact from the canal and details of the proposed wind turbines. Would like to see how the potential role of the existing large channel and basin that has been created fairly recently relates to this application and previous applications. There are positive elements in the project as a whole but it still suffers from a lack of clarity in trying to see how the master plan fits together.

3.1.8Hertfordshire Highways – these proposals appear to be the repair / replacement of existing facilities on the site and will not introduce any new operations. It appears that there will be a reduction of 8 car parking spaces (45 to 37). The existing use of the site is ‘watercress farming, fishing, and farming’. It does not appear the proposals will materially increase traffic movements from the site above that which the legitimate existing use could generate. Consequently the development is unlikely to result in a significant impact on the safety and operation of the adjacent highway. No objection or conditions to the grant of permission.

3.2Site/Press Notice

3.2.1Yes. Both. Expired 13 March 2009.

3.3Neighbourhood

3.3.1Number consulted: 94

Number of responses: 3

4.Summary of Representations

4.1Car parking within the site has been partially constructed. Some fencing has been erected. Some of the works are on land outside the applicant’s control. Access to the site over the Bridge at the foot of Rousebarn Lane is wholly inadequate. Gade Bank is a private road which prevents turning. Vehicles will park in Gade Bank. Increase in traffic rather than a decrease. Careful consideration needs to be given to the siting of any solid fuel burning equipment. Concern if the footpath from Gade Avenue would be obstructed by the proposed fences. Footpath leading to Cassiobury Park already floods when there is rainfall / precipitation. A culvert is needed.

5.Reason for Delay

5.1Committee cycle.

6.Relevant District Plan Provision

6.1East of England Plan.

6.2Three Rivers Local Plan 1996 – 2011. Metropolitan Green Belt. Local Wildlife Site.

6.3Policies GEN1, GEN1a, GEN 4, GEN6, GEN7, GEN8, N1, N3, N4, N5, N6, N7, N9, N10, N12, N13, N13, N15, N16, N17, GB1, D1, D6, D8, H17 T7, T8, T9, T10, T11, L8, L13, L14 and Appendix 1.

6.4Supplementary Planning Documents – Sustainable communities. Open Space, Amenity And Children’s Playspace Spd.

7.Analysis

7.1Introduction and Principle of Development

7.1.1The use of the land for watercress growing and coarse fishing is considered to have existed on the land for several years. Both of these uses are considered to be acceptable in the Metropolitan Green Belt.

7.1.2It therefore falls to be considered if the proposed development for the replacement pump houses would affect the openness of the Metropolitan Green Belt. Similarly, the same considerations apply to the watercress filtration ponds and proposed fencing and gates to the site.

7.2 Design and Access Statement

7.2.1The applicant has submitted a Design and Access Statement that sets out the Design principles; design concept; consultations with stake holders; the Design component setting out the amount, use, layout, scale, appearance and landscaping; the Access component setting out disabled access, car parking, additional traffic flow and site access, and on site vehicle turning facilities.

7.2.2In terms of its scope the Design and Access Statement covers the principle headings as set out in the CABE advice – “Design and Access Statements: How to write, read and use them”.

7.3Green Belt

7.3.1The use of the site for watercress farming is an agricultural use. This is a use which is acceptable in the Metropolitan Green Belt. The purposes of including land in Green Belts is to:

Check the unrestricted sprawl of large built up areas;

To prevent neighbouring towns from merging into one another;

To assist in safeguarding the countryside from encroachment;

To preserve the setting and special character of historic towns; and

To assist in urban regeneration by encouraging the recycling of derelict and other urban land.

It is considered that the proposals facilitate bringing the site back into agricultural use and therefore do not conflict with the purposes of including land in the Metropolitan Green Belt.

7.3.2The use of land in Green Belts is to fulfil the following objectives:

To provide opportunities for access to the open countryside for the urban population;

To provide opportunities for outdoor sport and recreation near urban areas;

To retain attractive landscapes and enhance landscapes, near to where people live;

To improve damaged and derelict land around towns;

To secure nature conservation interests; and

To retain land in agricultural, forestry and related uses.

The proposals retain the land in agricultural use. The proposals also provide opportunities for outdoor recreation. The erection of 2m high fencing is considered to enable the site to be brought back into use and reduce opportunities for trespass and associated problems arising from trespass. The agricultural use of the site has been dormant for several years. By making the site secure, this enables the site to be retained for agricultural use and enables the landscape of the site to be managed and improved rather than becoming overgrown.

7.3.3Herts Biological Records support the proposals for the site as this will restore an historic land use and create local jobs. The proposals also aim to retain and enhance the local biodiversity of the site and in furtherance of this aim, request conditions for Habitat Management Plan, Bats and trees, Birds and trees, and control of lighting. This enables nature conservation interests to be secured.

7.3.4The applicant has applied to erect 2m high fencing around the perimeter of the site and has considered several options. The proposed weld mesh fencing is considered to meet the objectives of providing security to the site whilst still maintaining permeability and visibility. Thus ensuring that the openness of the Metropolitan Green belt is maintained.