Thursday, 27 March 2014

Ditch Management

checked and it's the SSSI Site Management Statement that describes rotational ditch clearance:

Ditches provide the means of achieving a higher water level on the site. Only one new ditch should be necessary across the site  -  alongside the Diagonal Path on the North Marsh  -  others should run along the site edges. The Hydrological Report (CarlBro, 2000) contains details of the recommended positions of new ditches.

Management of existing ditches  should occur between October and March (preferably October/November), the objective being to clear each section of ditch once every ten years. In any one year no more than 20% of the entire ditch network should be cleared. Ditch profiles would preferably include a shallow berm and dredgings should ideally be spread on the canal side of the ditches, not over the Marshes.

This is from the HLS agreement

HB14- Management of ditches of very high environmental value Land parcels and associated features managed under this option:
RLR Field Number: TQ35870382
Features: F09 High environmental value boundary, SB19 Uncommon Birds, WO?
Ponds - BAP habitat, W08 Reedbeds - BAP habitat
RLR Field Number: TQ35875015
RLR Field Number: TQ37993352
Features: F09 High environmental value boundary, G11 Habitat for invertebrates,
8810 Reed Bunting, SL01 Uncommon Lower Plants (e.g. mosses), SM08 Water Vole

General description of the management required:
This option is aimed at the management of ditches of very high environmental value.
These can occur in grassland, wetland and arable landscapes. The aim is to provide a variety of species-rich stages of natural succession, from open water, to ditches full
of emergent species, and to maintain local historic landscape character. Target farmland birds, insects, plants and mammals will benefit from an improvement in the
structure of ditches through sympathetic vegetation cutting regimes.

Indicators of Success
• Ditches must contain water for at least 9 months of the year. The ditch on Rammey Marsh is more ephemeral but there should be localised pools along the ditch length providing refuges for water voles.
• There should be no more than 1 0% of the ditch length with heavy shade i.e where vegetation overhangs more than half the width of the channel surface.
• There should be approximately 30% early, 30% middle and 30% late successional ditches on the holding.
• By year 5 at least 5 of the following quality indicator species should be occasional and at least 3 should be frequent: Broad-leaved Pondweed, Curled Pondweed,
Water Plantain, Spiked Water Milfoil, Water-cress, Fool's Water-cress, Yellow Flairis, Water-mint, Water Crowfoots, Charophytes.
• By year 3 there should be no woody scrub growing on the ditch banks. Localised low cover such as bramble is acceptable to provide cover for water voles.
• Filamentous algae should be less than 10% cover.
• Non-native species such as water fern/parrot's feather/Hydrocotyle should be absent and New Zealand Pygmyweed should cover no more than 5% of affected
• The water should be clear enough to allow the ditch bottom to be visible, unless obscured by aquatic vegetation, in at least 90% of the ditch length.
• Water depth should be minimum 0.5m except on Rammey Marsh where the ditch is ephemeral.
Management Prescriptions; the dos and don'ts of management.

The following rules apply across the whole area being managed under this option:
• Cut the emergent and aquatic vegetation according to the agreed rotational programme leaving the roots in the base of the ditch. Place the arisings on top of the bank for at least 12 hours before removing. Retain a fringe of emergent vegetation on alternating sides of the ditch.
• If cutting the vegetation using a digger, use the bucket to scoop the roots avoiding disturbing silt or cutting into the bed or banks of the channel. Some roots should be left in the channel to enable regeneration. Avoid tracking the digger along the top of the bank where water vole burrows may be damaged.]
• Maintain a varied sward on the ditch banks to provide cover for water voles. Control woody scrub so that it does not encroach onto the banks or shade the channel.
• Manage ditches and banks between 1 October and 28 February only.
• Do not re-profile the ditch unless agreed with your Natural England adviser.
• Re-profiled ditches must have their banks sloping at 45 degrees or less.
• Do not de-silt/dredge ditches unless agreed with your Natural England adviser.
• Following de-silting/dredging/re-profiling, bankside vegetation must be reestablished by natural regeneration.
• Remove cuttings from the edge of the ditch after trimming.
• Do not cultivate or apply fertilisers, manures or pesticides to land within 2m of the centre of the ditch or 1 m of the top of ditch banks.
• Only use mechanical means (including hand tools) to clean the ditches or trim the bank. Do not use herbicides.

On Monday, 10 March 2014, 22:30, Abigail Woodman <> wrote:
Hi Joan

We have discussed this tonight.

Ditch dredging, sections on rotation, is part of the High-Level Stewardship Agreement so we need to complain to the LVRPA for not doing this. Can as many as possible write please.


On 8 Mar 2014, at 17:58, Joan Yeadon <> wrote:

One thing that needs thinking about before the next so-called Marshes Management Workshop is management of the ditches.  For example, all of the willow trees and a lot of brambles along the ditch that runs alongside Coppermill Lane and a lot of trees on the other side of Coppermill Stream have been cut down.  At the last workshop, we were told this was to stop leaves falling in the ditch.  

Having had another look at the ditch this afternoon, I consider that what has been done is inappropriate.  Ditches do need to be maintained to keep the oxygen levels up and stop them getting overgrown.  As well as cutting down a few self-seeded willows and brambles, it would not hurt to dredge the ditch - to clear out the dead leaves.  Also, there is a serious infestation of Crasula Helmsii in Coppermill Ditch that should be removed. 

If I was managing the job, I would remove the Crasula Helmsii by hand, lay it on the bank overnight to let any critters find their way back into the ditch and then take it away and burn it.  Then I would dredge that half of the ditch this year and come back next year to dredge the other half.  Crasula Helmsii removal would probably have to be done every year - just to keep it under control and stop it choking everything else out.

Kindest regards


Joan Yeadon 

Tel: 020 8809 2475

Mob: 07908 398 905

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