Introduction & Project Background
In 2012, the Sussex Wildlife Trust, the Environment Agency and the Woodland Trust began an innovative project on the Ouse River in East Sussex, called Sussex Flow Initiative (SFI). The project aimed to investigate ways that catchment-wide natural flood interventions can help to reduce flood peaks in areas vulnerable to flooding, whilst increasing biodiversity and providing multiple benefits at a landscape scale.
SFI works with the Catchment Partnership and others to develop new approaches to natural flood management (NFM) measures across the 672 km² area and 1220 km of river in the Ouse catchment, and to make recommendations on how and where to target them. We are a pilot project to gauge the potential benefits of trees, woods and other low cost NFM measures in lowland UK rivers, delivering NFM measures in partnership with communities and landowners. SFI aims to lead the field in showing that there are positive NFM options which can work alongside traditional flood risk management in rural and urban communities.
One of the key targets of SFI is to promote and integrate a holistic approach to water and land management across the catchment, and to make the catchment more resilient to flooding and drought, through a combination of demonstration and advocacy. Although the effects of NFM such as tree planting can take time to show their benefits, multiple actions taken now can provide positive natural capital benefits far into the future. SFI hopes to understand and articulate the natural capital benefits of NFM, so that we can make the best choices for now and for future generations.
In 2016, we entered into a new partnership with a Local Authority, Lewes District Council, who pledged their support by collaborating with SFI on NFM upstream of Lewes town, and in 2017, the Environment Agency launched a National Programme of NFM. These are exciting times for the integration of landscape scale approaches to flood management. The following report is a summary of the achievements of the SFI and TrUck projects over the last 5 years. We hope that the information helps to provide further evidence of the need for future work in lowland Natural Flood Management.
We have created over 1,000,000 litres of new, seasonal water storage which can be activated in every rainfall event
including a flood storage pond and over 100 pocket ponds.
We have also advised on the creation of at least 500,000 litres more seasonal water storage.
We have engaged with 150 landowners
comprising over 5,650ha including around 33% of the Uck floodplain
and over 11% of the Ouse floodplain.
We have had a positive influence on at least 9.5km of the river network
and a minimum of 70ha of land directly downslope or downstream of the river network.
We have held a range of events benefiting at least 40 landowners
and 2,000 local residents.
Our work has been supported by over 150 volunteer work days on everything from GIS mapping to hedge planting.
The value of this volunteer time is in excess of £17,500.
Over the 5 years, organisations have contributed at least £225,000 of their time ‘in kind’.
The work of SFI is contributing to providing Natural Capital through Provisioning Services, Regulating Services and Cultural Ecosystem Services. This includes:
Creating hedgerows in at least 2.6km of Buglife B-line target pollinator areas
Enhancing genetic and bio-diversity by linking landscapes via new habitat networks
Helping to improve water quality
Sequestering between 11,780 and 15,200 tonnes of CO²
Contributing to the reduction of erosion / run-off, and the retention of soils
Using hedges to help to store and slow down around 12,900m³ (tonnes) of water during rainy periods.
We produced a model (EcoServ-GIS) which maps where 9 different essential natural services such as water purification are being provided in the Ouse.
With partners and contractors we have developed a range of computer models and mapping tools to assess woodlands and rivers in the Ouse for their suitability / unsuitability for NFM measures.
We have supported three research projects up to PhD level including projects on the design of Large Woody Dams and their influence on channel flow and geomorphology.
We have worked closely with at least 30 key national and local stakeholders, and a number of lead and local flood authorities.
We have conducted detailed sub-catchment mapping of nearly 5,000ha of the Ouse catchment
and have facilitated River Habitat Surveys of over 51km of the main river, covering 10 sub catchment waterbodies.
What else?
We have disseminated information about Natural Flood Management in a number of ways including:
- Creating 3 websites / pages with a cumulate visitor traffic to pages and blogs of over 12,400 people
- Created an online video which had 3,523 views in under one week and 130 You-Tube views
- Created a Facebook page with 135 followers
- Tweeting with at least 2175 views (41 likes, 31 Retweets, 10,315 Impressions)
- Articles in magazines and newspapers with a combined readership of at least 40,000
- Radio interviews to shows with at least 13,000 listeners
We have produced our own guidance on NFM, including a guide to Natural Woody Material in rivers for NFM. And we have contributed to at least 6 major publications and case studies including:
- CaBa (Catchment Based Approach)
- WwNP, Woodland Trust Woody debris guidance
- Rewilding Britain’s Rewilding reduced Flood Risk document
We have achieved the aims we set out in our original Vision document and more and have assisted major projects outside our project area including The ARC project, Knepp Wildlands, Powdermill stream Sub catchment plan and others.
For more information and to read the full report please visit www.sussexflowinitiative.org
Credits:
Fran Southgate