We’ve been retrofitting for years !

Written By: Market Development Director, Hydro International.

Few people would argue these days against the benefits of incorporating sustainable drainage techniques into new developments. But what about tackling our existing flooding and water quality problems ?

The EU Water Framework Directive (WFD) requires us to tackle a whole range of pollutants entering our water bodies and everyone is more than aware of the many flooding issues we have encountered in recent years, from both rivers as well as sewers.

What many people aren’t aware of is that there are solutions to retrofitting sustainable drainage and we’ve been fixing some of the problems for years. And whilst there are many people that still think the only sustainable drainage options are ponds and swales, much progress seems to have been made in this area with a much greater acceptance of the role that proprietary techniques have to play in dealing with stormwater management issues.

Those of you who can remember watching Maggie Philbin tell us all about innovative new ideas and approaches on Tomorrow’s World back in the 80s, probably don’t recall seeing her tell us all about how building more and more roads and houses have affected the way in which rainfall runoff behaves. During an episode of Tomorrow’s World, which was shown in 1983,  Maggie used some really good models that Hydro  had built to demonstrate how flooding occurs.  She  went on to explain how Hydro-Brake® Flow Controls work and how they had been used to great effect to cure a repetitive sewer flooding problem in Wadley Road in North East London – a great example of a retrofit solution. Here’s a link on our website to the 3 ½ minutes extract from the program –


On a larger scale, there have been several flood alleviation dams built over the years on rivers and watercourses to cure severe flooding problems downstream, all incorporating huge Hydro-Brake® Flow Controls. These are retro-fit stormwater management schemes on a huge scale, none more so than the White Cart Water Flood Prevention Scheme. Glasgow City Council have produced an excellent website explaining all about the project – see http://www.whitecartwaterproject.org/ and there’s also details of another similar project called Weedon Dam on our own website – http://www.hydro-international.biz/stormwater/flowcontrol_casestudies.php

When it comes to water quality, there fewer UK examples of retrofitting due to the lack of legislative drivers to date. That is about to change! Once the National SUDS Standards have been published later this year, it is expected that dealing with water quality from new developments will be a requirement and we’ve already mentioned the objectives of WFD. In the USA, The Clean Water Act was implemented during the 70s and has driven the need for water quality treatment techniques. There are many proprietary solutions available in the USA, as a result, and one in particular is a product called Filterra™ which we have recently introduced into the UK, and which has been used in many retrofit applications to cure the same problems as we have to deal with here. Case Study details can be viewed at –


You can also see what the City of Lakewood, California had to say about a retro-fit highway project where they incorporated Filterra™ by clicking here – http://www.lakewoodcity.org/video/10_11_09_bioretention.html


Comment on this item

Your email address will not be published. Required fields are marked *

I have agreed to the terms & conditions