13 February 2018

Designing for the rainy season

Managing a free resource can have real benefits....

Most of us who live in the UK have experienced periods of water shortage and in recent years there have been a number of hosepipe bans across the south of England.

Thames Water monitor rainfall, ground water levels and reserves constantly. In 2017 monthly rainfall was below average in both spring and autumn/winter, especially so in April, October and November. In December 2017 groundwater levels were showing signs of recovery, but they remained generally ‘Below Normal, or ‘Notably Low’. Reservoir storage was at 75% of average capacity.

Our clients are often keen to incorporate sustainable technologies within their project but naturally cost and payback periods have to be considered. It is easy to specify ‘green’ systems of one sort or another but overall budget has to be borne in mind – fortunately conserving water can be relatively low-cost and easy to justify.

At its simplest, installing water butts to collect rainwater from roofs can provide water for flower beds and small lawns. Harvesting rainwater and storing it in a tank concealed below ground will increase capacity significantly. Incorporating a filter to remove leaves and debris and a submersible pump for delivery will provide water for not only garden use and washing cars but also flushing toilets, running washing machines and other non-potable uses.

On a number of occasions we have arranged the installation of boreholes which can provide an abundant supply of water free of charge. A geological prognosis is undertaken to confirm the presence of suitable aquifers and their depth below ground. A small drilling rig then sinks the bore, flexible pipework is installed and a pump delivers water to the surface for distribution. The water which is available may be potable without treatment; if not a UV system can be installed for a truly independent supply.  

Related: Ashbrook Apartments, Lake House, Sustainable Design