Editing IPCC:AR6/WGII/Chapter-6 (section)

==== 6.3.4.6 Water Provisioning and Management ====

<div id="h3-26-siblings" class="h3-siblings"></div>

The role of NBS has been increasingly recognised for improving urban water management, emphasising it’s contribution for climate-adapted development and sustainable urbanisation ( ''robust evidence'' , ''high agreement'' ) ( [[#Wong--2009|Wong and Brown, 2009]] ). NBS that protect or restore the natural infiltration capacity of a watershed can increase the water supply service to various extents, improving drought protection and providing resilient water supply (Drosou et al., 2019; [[#Krauze--2019|Krauze and Wagner, 2019]] ), although different forms of NBS (e.g., street trees, parks and open space, community gardens, and engineered devices such as rain gardens, bioswales or retention ponds) contribute in different ways to increasing stormwater infiltration. Additional sources of water may be available to replace the water supplied by NBS, such as rainwater harvesting, inter-basin transfers or desalination plants. Reliance on naturally sourced, locally available surface water and groundwater is more energy efficient and economical than desalination or water reuse for potable use (Boelee et al., 2017), while rainwater harvesting is even more economical. Increasing the amount of green space in urban areas can secure and regulate water supplies, improving water security ( [[#Liu--2018|Liu and Jensen, 2018]] ; Bichai and Cabrera Flamini, 2018). However, [[#Bhaskar--2016|Bhaskar et al. (2016)]] reviewed the effect of urbanisation and NBS on baseflow and suggest that the confounded effects of infiltration and evapotranspiration losses, combined with the subsurface infrastructure (sewer systems) and geology, makes it difficult to predict the magnitude of baseflow enhancement resulting from the implementation of NBS in cities.

To maximise the adaptation benefits of NBS for urban water supply research suggests that managers and planners consider NBS as alternatives to traditional stormwater management techniques, where possible, since these solutions can promote groundwater recharge. As green infrastructure is increasingly being used for stormwater absorption in cities (McPhillips et al., 2020), rain gardens, wetlands, or engineered infiltration ponds and bioswales are the NBS most likely to promote recharge, reduce evapotranspiration and contribute to water provisioning.

<div id="6.3.4.7" class="h3-container"></div>

<span id="food-production-and-security"></span>