HEALTH AND SANITATION 33
Avoiding common mistakes Van Giesen said a common mistake people make when it comes to rainwater catchment systems is assuming they can be installed and then left alone. With domestic water lines, people know there will be little – if any – change in water quality from day to day. Rainwater catchment systems, however, are subject to climate variability, debris, freezing temperatures, which must be planned for and then monitored.
Additionally, he said many commercial projects are doomed by overly complicated designs that not only drive up installation and maintenance costs, but increase the likelihood that a system will be misunderstood, poorly maintained or value-engineered out of a project altogether.
“ You can always solve a problem with one more valve, one more control point, one more device, one more appurtenance. On paper it looks good, but at the end of the day, someone’ s got to understand and maintain all of that,” he said.
Pump selection is another area where he said mistakes are common. Choosing the wrong type of pump or control system can lead to inefficiency or failure, especially in systems serving buildings with variable demand. Van Giesen stressed that pump selection requires experience and shouldn’ t be treated as an afterthought.
“ Picking the right kind of pump and the right kind of control is something that takes some experience, and frequently we see mistakes made by people unfamiliar with pumping. Another one that I ' ve seen over the years is the wrong types of storage vessels. Often storage vessels are designed in places where it’ s just too cold,” he said.
Van Giesen said that when the rainwater system is integrated into the building at the beginning of the design process the overall chances of success of the project are greatly increased. This includes the shape of the roof and its orientation, how the downspouts – whether internal roof drains or external- are directed toward the storage tank, and where the tank and pumps will be stored.
“ So often rainwater systems are just thought of as,‘ Well, we’ ve designed the building – let’ s put a rain system on it’,” Van Giesen said.
Incentives and awareness Van Giesen said while the model plumbing codes contain language referencing rainwater catchment systems, and are available to most states in the US – something that was not the case only 15 years ago – more needs to be done to encourage their implementation and use.
“ The rainwater system, by definition, is not necessarily the sum of its parts – they have to work together.”
Because water is relatively cheap compared to other utilities, Van Giesen said many people are reluctant to invest in a rainwater system that can take more than a decade to pay off.
“ We need policies that encourage people to do this – perhaps with tax incentives, perhaps with rebates – to get people to invest in these systems because the return on investment can be really challenging, especially in the commercial world where we’ re paying so little for water,” he said.
Along with this, Van Giesen – a member of ARCSA International’ s Education and Research Council – said public awareness campaigns, school programmes and even rain barrel initiatives are vital to helping increase people’ s literacy about water and where it comes from and can play a crucial role in helping address flooding and water scarcity issues. The latter, he noted, have been successful in the South for years.
“ You can’ t discount the importance of rain barrel programmes. As people learn more about the power of harvesting rain, they begin to use them for their gardens and maybe down the road, they want something bigger.”
While small-scale efforts like rain barrel programmes can spark greater interest and adoption, he said broader change has been slower than he expected.
He said:“ I thought we’ d be a lot further along by now. When I started in this business in 2007, Georgia was in the middle of a big, huge drought and it was effectively illegal to capture rainwater in the state. But despite the slower-than-expected pace, the industry is bigger than ever, public interest continues to grow and I’ m sure that we will see more and more systems over the next three to five years.” PA
August 2026 Volume 32 I Number 06 www. plumbingafrica. co. za