Welcome to River of the Month! Every month, we spotlight a different river, sharing its wonders, its challenges, and the incredible people fighting to protect it. This month is…

The River Ouse (Sussex)

 

By Matthew Bird, Love Our Ouse

 

The Sussex Ouse flows through the heart of Sussex, rising near Slaugham in the High Weald and passing through towns and villages including Lindfield, Uckfield, Barcombe and Lewes, before reaching the sea at Newhaven. Its catchment contains an extensive network of tributaries, wetlands and floodplains.

The river is home to a rich mix of wildlife and fish, including migratory sea trout, eels and estuary species, as well as countless invertebrates that underpin the whole ecosystem. Loved by local communities for walking, fishing and nature, the Ouse is also under increasing pressure from pollution, habitat disruption and climate change.

 

River Facts

 

Did you know?

The Ouse has a long history of navigation, milling and river engineering, with locks and modified stretches shaping parts of the river we see today.

Length:

56 km (35 miles)

Catchment area:

647 km²

County:

West Sussex and East Sussex

Fish Biodiversity:

High – Coarse fish, Eel, Sea Trout, and estuary species such as Mullet and Bass

Sewage Discharges in 2024:

4,824

Ecological Status:

Of the 25 water bodies on the River Ouse, 13 (52%) fail to reach the Good Ecological Status.

The River Guardians

 

Love Our Ouse is a community-driven group bringing people together to celebrate, act for, and learn about the Sussex Ouse from source to sea. Their work includes raising the river’s profile, connecting local people with their waterway, citizen science activities, and campaigning for river rights.

Love Our Ouse has been instrumental in driving the development of a Rights of Rivers Charter for the Sussex Ouse in partnership with Lewes District Council and others, a pioneering move to enshrine the river’s right to flow, be free from pollution, support biodiversity, and have an influential voice in environmental decision-making.

Partners and Projects

 

Love Our Ouse helps channel this growing influence into practical action, local engagement and stronger protection for the river. They also highlight the importance of partnership working across the catchment.

Key agencies are already working hard to protect, enhance and invest in the Ouse, particularly through the Adur and Ouse Catchment Partnership, which includes The Ouse and Adur Rivers Trust, Lewes District Council, IFCA, Adur Farmers, South Downs National Park, Sussex Wildlife Trust, the Environment Agency, Brighton University, RSPB, Southern Water, South East Water, Love Our Ouse and others.

 

Key Challenges

 

Despite its ecological and cultural importance, the Sussex Ouse confronts several serious pressures:

Water Quality & Pollution

• Nutrient enrichment (notably phosphates), sewage overspills and surface runoff from agriculture and urban areas mean many water bodies within the catchment do not meet Good Ecological Status.
• In fact, 52% of these water bodies fail to reach Good Ecological Status, a result of either Poor or Moderate levels of phosphate.

Habitat Modification

• Channel straightening, locks, weirs and impoundments disrupt natural flows and fish movement, reducing habitat quality and oxygenation.

Emerging Chemical Threats

• Like many UK rivers, the Ouse is impacted by “forever chemicals” and legacy pollutants that conventional treatment systems struggle to remove

Flooding & Hydrology

• The river’s flashy response to heavy rainfall can lead to rapid rises in water levels and flood risk, exacerbated by historic drainage and loss of floodplain connectivity.

Invasive species

• Non-native species such as Himalayan Balsam deteriorate banks and smother native vegetation.

Key Solutions

 

To restore and protect the Sussex Ouse, key solutions include:

Strengthening Legal Protection

• Supporting the Rights of Rivers Charter and aligning local planning decisions with the river’s rights to exist and regenerate.

Upgrading Sewage Infrastructure

• Investment in treatment works and drainage systems to reduce overflows and nutrient discharges.

Barrier Removal & Habitat Reconnection

• Modifying or removing obsolete weirs and locks to improve fish passage and natural flow regimes.

Nature-Based Solutions

• Expanding wetland creation, floodplain reconnection and riparian buffer zones to enhance water quality and biodiversity.

Community Science & Monitoring

• Empowering local volunteers to gather water quality data, report pollution and inform restoration efforts.

Engaging Landowners & Farmers

• Promoting river-friendly farming practices that reduce runoff and improve soil and water health.

Representation

• Ensuring that the river is reflected in all decisions that affect it through the most impartial mechanisms possible.

A final message from Love Our Ouse

“Promoting a culture of care is very important, not only for the river but for all nature. If we are to protect the river against the numerous challenges it faces, we must first learn to love the river and rebalance our relationship with all nature.

Like many in our community and others around the world, we share a deep connection to our river—it’s the reason we’re here. Our relationship with it has become unbalanced, and we believe the Ouse River Rights Charter offers a clear path to restoring that balance, fostering a healthier river and stronger, more resilient communities.”

Take Action

 

If you would like to help those working to protect this beautiful Sussex river and support Love Our Ouse, please click here:

If you found this inspiring and would like to find out how you can protect your own local river by joining or creating your own river community group, visit our River Rescue Kit.