The aim of the Living Building Challenge Water Petal is to ensure designs that treat water as a precious resource. The water cycle system of a building must leave nothing to waste. Expert presenters were Chantal Ramcharan-Kotze, Eric Hough & Cara Lucas, and Jonny Harris – who spoke about why water is such a critical issue in the built environment; and demonstrated what can be achieved through local and international case studies.

Dr Chantal Ramcharan-Kotze, Business Development Lead at The Water Research Commission, presented ‘National Context – Water, Innovation & Sustainable Growth’. South Africa currently ranks as the 65^th most water stressed out of 176 countries; and, in terms of freshwater availability, is ranked at 148 out of 180 countries.

These facts present significant challenges in terms of the Water-Energy-Food nexus, where water, energy and food security are highly coupled and interdependent problems. The situation is exacerbated in the face of climate change, with shrinking arable land and increasing uncertainty and unpredictability around resource availability. In addition, in terms of policy and sectoral planning, there is no clear alignment between agriculture and energy-water constraints within the development agenda.

Ramcharan-Kotze went on to say that, while patent analysis indicates that South Africa has a higher-than-average innovative capacity in the water sector, the uptake of innovative measures remains slow in the face of preferred traditional approaches. Moving forward, closer ties are needed between understanding emerging market opportunities, moving innovative solution towards implementation, and investment from the funding community.

Eric Hough & Cara Lucas, Vice President & Environmental Specialist at Natural Systems Utilities (NSU), spoke about ‘Leading the Country in On Site Water Treatment and Reuse Solutions’. Offering an international perspective, Hough and Lucas identified the challenges posed to traditional wastewater networks in the face of such threats as Hurricane Sandy, which resulted in 11 billion gallons of untreated or partially treated sewage overflow; sea-level rise (SLR) induced flooding; and seismic events.

Onsite Water Treatment

Alternative wastewater treatment systems were then presented in the context of the case study of Battery Park City, NYC, which has resulted in:

• Six in-building water reuse systems serving eight buildings in BPC.
• 2,000 residents who are capable of reusing nearly 605,000 litres/d of renewable water sources.
• 15 years of operating data, with ZERO permit exceedances and ZERO user complaints/public health concerns.
• Net-zero and net-positive energy systems now possible with thermal energy recovery.
• The ability to improve resiliency in wastewater treatment and water supply.

Finally, Jonny Harris, Founder of Isidima Design & Development, spoke about ‘Case Studies in Building Thriving Water Sensitive Cities’, focusing on the role of sanitation and wastewater recovery for building thriving cities, and the value of a water efficient approach to secure equal access to water and sanitation for all.

Building Thriving Water Resilient Cities

Harris’ presentation opened with water use in the home (volume used and volume wasted); the social, economic and environmental impacts of wasting water; and the need to close the loop to close the gap – how water savings generated by water re-use and water efficient toilets can reduce pressure on bulk infrastructure.

Case studies cited were:

• Water re-use for toilet flushing (Sustainability Institute, Stellenbosch)
• Harnessing greywater for a greener environment (Genius of SPACE, Franschhoek)
• A Living Building Challenge (LBC) design approach for water efficient developments (Corlett Drive, Johannesburg)
• The business sense of water re-use (ABinBEV brewery, Port Elizabeth)
• Low flush toilets for water efficient schools (Eastern Cape).

This free ‘Net Positive Water’ webinar is CPD-validated by SACAP and ECSA and is available online: https://www.greened.co.za/courses/net-positive-water-buildings/.