Everybody living or working in the Calder Valley can make small changes to slow the flow of stormwater.
Many small interventions, to slow run-off, could result in a significant amount of water being temporarily stored during storm events in our urban areas.
This will help to reduce peak flows (see the detailed Storm Hydrograph) which, together with catchment management and traditional flood defences, would contribute to reducing the scale and damaging effects of flood events.
Principles of SuDS
Sustainable Drainage Systems (SuDS) mimic the natural cycle of water management, by retaining water where it lands (instead of shedding it quickly to drains and watercourses, which can lead to floods).
SuDS reduce rainwater runoff from a given site, filter it to improve water quality, and slow its journey downstream.
Sustainable drainage allows us to Slow The Flow in Calderdale’s urban environment. This complements rural Natural Flood Management (NFM) measures. SuDS and NFM are in fact describing the same thing, but SuDS is more often the term associated with the urban environment.
We can also consider altering our behaviour during flood events to discharge less water into drains (much as we might behave to conserve water during drought).
During and after the devastating Boxing Day Flood 2015, thousands of us gave our time and money to help friends, family and neighbours recover.
If we all work together to take action and invest in our own properties (whether they flood or not) we can help reduce the threat of similar levels of flooding in the future, and the need to help clean up on such a large scale.
If every person in Calderdale (200,000 approx) stored an average of 0.1m³ (about a half-full bathtub) of water in a flood event, we could store around 20,000m³ (about 5 m³ for every property that flooded on Boxing Day 2015).
This could make a real difference, especially to water quality in areas which suffer from sewer flooding.
Retrofitting urban SuDS is also a chance to contribute to local Green Infrastructure, improving:
- wildlife value
- air quality
- the appearance of your property.
Locations such as:
- Back Gardens
- Front Drives
- Bin stores
- Roadside verges
- Public spaces
- Central reservations
- School grounds
- Car parks