As world population reaches nine billion by 2050, the number of people in the world without safe drinking water will continue to increase. A report released on March 18, 2018, by the UNESCO World Water Assessment Programme (WWAP) at the World Water Forum in Brazil, indicates that at present more than two billion people do not have consistent access to safe drinking water.

The report, Nature-Based Solutions for Water, indicates that increasing population coupled with climate change is exacerbating the safe drinking water problem. That said, it postulates that natural solutions, some of which have been around many years. can provide help with this problem. According to Audrey Azoulay, the Director-General of UNESCO, "Demand for water is set to increase in all sectors. The challenge we must face is meeting this demand in a way that does not exacerbate negative impacts on ecosystems."

Stephen Uhlenbrook, WWAP Coordinator, and Richard Connor, Editor-in-Chief of the report state in the preface that the report "focuses on opportunities to harness the natural processes that regulate various elements of the water cycle which have become collectively known as nature-based solutions (NBS) for water."

Presently there are a variety of types of NBS for water from personnel such as dry toilets, to landscape-level such as conservation agriculture. Nevertheless, water resource management relies greatly on human-built or the so-called grey infrastructure. The report states that it's idea "is not necessarily to replace grey infrastructure with green infrastructure but to identify the most appropriate, cost-effective and sustainable balance between grey infrastructure and NBS considering multiple objectives and benefits."

How can these objectives be met? One possibility is to re-examine indigenous/traditional knowledge and approaches that tend to rely less on construction and more on greener approaches and to incorporate these approaches into infrastructure. "Working with nature rather than against it would enhance natural capital and support a resource-efficient and competitive and circular economy."

Uhlenbrook and Connor further state "There are a number of mechanisms that can be used to accelerate the uptake of NBS for water. Payment for environmental services schemes and green bonds have been shown interesting returns on investments while lowering the need (and costs) for larger, often more expensive infrastructure required for water resources management and the delivery of water supply and sanitation services."

The report recognizes that a greater reliance on NBS will not necessarily be easy. "Implementation of NBS involves the participation of many different stakeholder groups, thus encouraging consensus-building and helping to raise awareness about what NBS can truly offer to improve water security." Uhlenbrook and Connor further state that the report has endeavored "to produce a balanced fact-based and neutral account of the current state of knowledge, covering the most recent developments pertaining to NBS for water, and the various benefits and opportunities they offer in terms of improving the sustainable water resources management."

I personally believe that WWAP is on the right track. I believe that incorporating NBS with grey infrastructure, while it may be ultimately overwhelmed by the combined specters of rapid population growth and climate change, represents a way to at least slow down the problem and, perhaps, to solve it.

Citation: WWAP (United Nations World Water Assessment Programme) UN-Water, 2018. The United Nations World Water Development Report 2018: Nature-Based Solutions for Water. Paris, UNESCO.