Navigating the Future of Urban Flood Management: A Guide for Merchants

With urbanisation, population growth, and climate change accelerating, towns and cities face increased risks of flooding and watercourse pollution. These challenges are expected to become even more frequent in the coming years. In response, the government is implementing Schedule 3 of the Flood and Water Management Act, becoming mandatory in 2024, more than a decade after its initial recommendations. This legislation will require housebuilders and developers to adopt new water management solutions, with a strong focus on sustainable drainage systems (SuDS).

Understanding Schedule 3, SuDS, and SABS

In conventional drainage systems, rainwater runoff is typically captured in a combined sewer before it travels to a water treatment facility. However, with new housing developments, the fixed capacity of existing pipe networks can lead to more frequent and severe flooding episodes. Schedule 3 aims to mitigate this by using SuDS to regulate rainfall and reduce the volume of water flowing into sewers from new developments. This involves implementing features like permeable surfaces, rain gardens, and soakaways to decrease the overall amount of water entering our sewers.

As part of Schedule 3, SuDS approval bodies (SABs) will be put in place, which will give developers approval of their drainage designs and the products installed as part of them. SABs will decide if a developer’s application meets the new national and mandatory standards before construction commences, meaning housebuilders will not only need to design and build drainage systems in line with an approved drainage plan, but they will also need to demonstrate how they will include more SuDS. Only certain approaches will meet these requirements, and it’ll be important to understand what those are, and how they can be implemented.

Merchants and Schedule 3: Building Stronger Relationships

This period of change offers merchants a unique opportunity to strengthen relationships with developers. By becoming a trusted source of education and insight on meeting Schedule 3 criteria, merchants can help developers secure new contracts more easily. Working closely with suppliers who offer products that meet national standards will ensure developers can satisfy the demands of the schedule.

Two key solutions will be permeable paving and rain gardens:

Permeable Paving

Schedule 3 promotes source control design, effectively managing water at its source to prevent surface water runoff. Permeable paving is an excellent solution, allowing water to drain where it lands while providing a robust surface for high-traffic areas. This paving needs complementary products, including grids, filtration textiles, sub-base aggregates, and membranes, to create a comprehensive solution.

For example, at Scholars Green, a luxury development in South Manchester, PH Property Holdings used Marshalls Priora permeable paving to ensure surface water drained into a specially prepared sub-base, significantly reducing flood risk while maintaining durability for regular vehicle traffic. As Schedule 3 becomes mandatory in England, the demand for permeable paving is expected to rise, with merchants being key suppliers for developers.

Schedule 3 has been in place in Wales for several years but, like England, Scotland chose not to adopt it when the original recommendations were made. However, its legislation has a long history of building SuDS policy into local planning laws due to more intense rainfall events. As a result, annual sales of permeable paving products such as Marshalls’ Priora are much higher as they provide a cost-effective solution. We expect to see sales of permeable paving increase in England as Schedule 3 is adopted, with merchants being a key outlet for developers to access the products.

Rain Gardens

Rain gardens are becoming increasingly popular in residential developments due to their dual role in flood management and enhancing biodiversity. They use plants and soil to collect and temporarily hold water from hard surfaces, allowing it to soak into the ground and be stored below, preventing quick entry into the sewer system. Rain gardens also reduce water pollution by acting as mini filtration systems, absorbing pollutants and releasing cleansed water.

With their environmental benefits and appeal to eco-conscious house buyers, rain gardens are expected to become a favored solution for developers seeking to meet Schedule 3 criteria.

Ongoing Support for Merchants

As a key supplier to merchants, our aim as Schedule 3 comes into play is to act as a source of support not only to those working in branch but to their customers, too. While some of our products can be utilised to help developers meet the specific criteria of the schedule and SABs, the expertise in our wider team, such as our Design and Engineering Team can be called upon to provide guidance on water management at a holistic level. On the broader topic, merchants can direct their customers to CPD workshops on SuDS Solutions and Climate Resilient Spaces, and work with suppliers to ensure you’re readily available with the products developers will come to rely on. Doing so will solidify you as one of their most trusted assets, and someone to work with for the long-term.

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