5 Members of CFAG met Simon Marrington of the Forestry Commission in North Yorkshire who has been seconded to a 2 year project: Slow the Flow in Pickering.
It is a partnership project led by Forest Research with Forestry Commission England, the Environment Agency, The North York Moors National Park Authority, Durham University, Natural England and the wider community. The lead funder is Defra with cooperation of landowners such as Duchy of Lancaster, North York Moors Railway and MOD.
“It is about working with nature to try and store more water in the landscape and slow its passage downstream. The new approach to flood management relies on making changes to the way the landscape is managed, so that the passage of rainfall to rivers and its movement downstream is reduced and delayed. This will involve a range of ‘measures’, including:
- Constructing low-level bunds
- Planting more trees, especially along streamsides and in the floodplain
- Restoring woody debris dams in small streams
- Restoring wetlands.
Whilst this will not prevent all flooding, it is expected to reduce the frequency of future floods in Pickering, as well as deliver a range of other benefits to the local environment and community.”
Pickering Beck Catchment – bunded storage option
We first visited Newtondale where there is a planned scheme for the EA to build small bunds in the valleys above Pickering which will come into effect only in times of flood. The area has some of the quickest rising water levels in the country but the water also clears quickly so if the arrival of the flood is delayed, even by a short period, the likelihood of flooding downstream is reduced. The water will be forced to spread out into small flood plains shown below where it will dissipate slowly.
The two earth embankment defences will protect around 60 properties in Pickering during low level floods such as 1999, 2000 and 2002. The scheme is designed to store up to 85,000 cubic metres of water.
Consideration has to be taken for local use such as the North York Moors Railway and local farmers and residents. Tourism is a major part of the economy as well.
Pickering Beck Catchment Land Management
We then moved on to view the area of the Levisham Estate at the Hole of Horcum where large areas are going to be planted with natural vegetation to slow down the flow from uplands. This will NOT be lines of conifers but mixed woodland and shrubland.
“Riparian and floodplain woodland can form a barrier to flood flows, helping to slow the passage of the flood peak and potentially increase upstream flood storage. Significant potential exists for planting riparian woodland within the Pickering Beck catchment, where the target is to create 50 ha of new woodland. The River Seven catchment is better suited to floodplain woodland and the aim is to plant a 30 ha demonstration woodland at one or more sites along the main river.”
Restoration of large woody debris dams
Finally we visited and area of upland forest at Cropton Forest where over 100 dams are being built across streams. It has been realised that for the last 50 years we have been managing upland forests in completely the wrong way. Streams have been cleared and ‘canalised’ so that water is speeded up and races down the hillsides in deep v-shaped valleys. As the ‘crop’ has reached harvest stage, it is possible to rectify this and by partially blocking these streams they will be ‘reconnected with their floodplain’.
The dams are loosely constructed so that water can flow through the gaps in normal times but during flood it cannot get through quickly enough and spreads out either in the woodland itself or into small floodplains.
CFAG will be monitoring the progress at Pickering but will also be researching what works and plans are in progress in the Catchment Areas above Cockermouth by contacting United Utilities (Landowners around Thirlmere) and the local Forestry Commission.
Thanks to Simon Marrington of Forest Research/Forestry Commission for the informative day.