4 November 2021 – Crompton Moor, Oldham, is a pilot project aiming to show how effective natural methods can be for preventing flooding. Between 2020 and 2021 City of Trees planted 2200 trees, thanks to Trees for Climate funding.
Summary of the project
Objectives for the site
1. Riparian planting to reduce surface water runoff entering the old Brook to reduce flood risk down catchment in Oldham.
2. Diversification of tree species in plantation woodlands to increase biodiversity and resilience of tree stock.
Crompton Moor is part of the South Pennines and covers an area of around 70 hectares, it is located in the north-east of Oldham close to the border with Rochdale. The Old Brook watercourse flows through the moor and feeds into the River Beal which passes through the towns of Crompton and Shaw.
The peatland has been degraded over the centuries by mining, drainage works to allow grazing, pollution from neighbouring industry and wildfires. As a consequence, the moor was less able to store water, which is needed to help reduce the risk of flooding following heavy rainfall to settlements adjacent to the River Beal.
City of Trees and partners haven been undertaking a programme of works on Crompton Moor which includes planting sphagnum moss, building five ‘leaky dams’ and planting over 4,000 trees on the slopes adjacent to the peat bogs.
Planting locations were identified through consultation with stakeholders and the Greater Manchester Tree and Woodland Strategy (All Our Trees) to identify appropriate and targeted planting locations. All the planting will contribute to the creation of the Northern Forest and help deliver the policy actions within the government’s England Trees Action Plan.
Details of the intervention
Working with a team of contractors a total of 0.96 net hectares/ 2.1 gross hectares were planted – total number of trees standing at 2200. Species planted include: sessile oak, hornbeam, crab apple, hawthorn, rowan, silver birch, common alder, goat willow, downy birch, gorse, guelder rose and pedunculate oak.
For the riparian planting, shrub species choice took into account the hunting territory of the Long Eared Owl population. Shrubby species, which produce fruit will attract amongst other species (small mammals) which are prey for the Long Eared Owl.
Key Stages of the Process
- Engaging with stakeholders including Natural England, Greater Manchester Ecology unit, GM Archaeological Advisory Service, Oldham Council, Environment Agency, Friends of Crompton Moor, local lead flood authority and the Forestry Commission, to ensure that the planting proposals were targeted in the right locations to maximise benefits and ensure that any existing important habitat space wasn’t compromised.
- Site visit with Forestry Commission deer conservancy advisor to discuss tree protection methods from browsing deer, known to be present on site.
- Project design e.g. planting plans and species mix.
- Procure trees, guards and other materials.
- Procure planting contractor.
- Oversee planting works.
Regular communications with Oldham Council, and the Friends of Crompton Moor will continue to assess the establishment of the woodlands planted. Likewise, City of Trees, will also undertake site inspections and will identify any beating up requirements for the following planting season. We will also examine trees for any evidence of deer browsing, pests and disease.
Natural flood management and water quality:
All the tree planting will help to intercept rainfall which will slow and reduce the amount of water that enters the Old Brook and its tributaries. Over time, the trees will increase the soil permeability and together with the water interception, will also reduce soil erosion.
Innovative delivery practices:
Trial planting of less palatable species without tree shelters to help determine if leaving trees unprotected is a viable alternative on site. The aim is to reduce plastic use and to examine the balance between any cost savings (from fewer shelters and stakes) and the higher tree replacement costs.
So far it has created an interest from the site users about why new woodland creation is important for biodiversity and natural flood management.
City of Trees has worked with the Friends of Crompton Moor and Oldham Council to produce a video which explains the benefits of tree planting around the moor.