Can water butts help with alleviating sewerage spills into the sea and water courses?

Water butts can contribute to reducing the impact of sewerage entering the sea and rivers through a process known as water attenuation or sustainable urban drainage. Here's how water butts can help:

  • Rainwater Harvesting:

Water butts collect rainwater from rooftops, preventing excess rainwater from overwhelming drainage systems.

By capturing rainwater at the source, water butts reduce the volume of water entering the sewerage system during heavy rainfall.

Rainwater Terrace water butts have attenuation valves built into each tier which lets a percentage of the water collected slowly drain away after the heavy rain period has ended leaving space for the next rainfall.

Water butt flood alleviation SuDs schematic diagram
SuDs water butt with attenuation valve that slowly drains away

 1. Reduced Surface Runoff:

  • Water collected in butts is water that doesn't immediately contribute to surface runoff.
  • Surface runoff from impervious surfaces, such as roads and pavements, can carry pollutants and contaminants into sewer systems and, subsequently, into rivers and seas. Water butts help to intercept and reduce this runoff.

 2. Relieving Sewer Overflows:

  • During periods of heavy rainfall, sewage systems may become overloaded, leading to combined sewer overflows (CSOs). CSOs discharge a mixture of storm water and untreated sewage into water bodies.
  • By capturing rainwater in water butts, less water enters the sewer system, reducing the likelihood of overflows and minimizing the impact on water quality.

 3. Promoting Permeability:

  • Allowing rainwater to be absorbed into the ground instead of flowing into the sewer system promotes natural permeability.
  • This helps to recharge groundwater levels and reduces the burden on sewerage infrastructure.

 4. Sustainable Water Management:

  • Water butts promote sustainable water management practices by encouraging the reuse of rainwater for gardening or other non-potable uses.
  • This reduces the demand for treated water from municipal supplies, contributing to overall water conservation efforts.

 5. Mitigating Urban Flooding:

  • By capturing rainwater and slowing its release, water butts can help mitigate urban flooding by reducing the rapid flow of water into drainage systems.
  • Flooding events can carry pollutants into water bodies, and water butts play a role in preventing such incidents.

 6. Community and Individual Action:

  • Encouraging the widespread use of water butts at the community and individual levels contributes to a collective effort to manage water sustainably.
  • This grassroots approach empowers individuals to make a positive impact on water quality in their local environment.


While water butts play a valuable role in localised water management, it's essential to recognize that they are part of a broader strategy. Comprehensive urban planning, green infrastructure, and sustainable water management practices are crucial for addressing the larger issue of sewerage and storm water pollution in rivers and seas.