The planning and design of nature-based solutions (or ABC Waters design features) can be guided by a set of design principles [1]. The principles related to water sensitivity and adaptability of the solutions are of particular significance.
Water Sensitivity
Water permeates the urban landscape and affects every aspect of the environment. A water-sensitive solution is one that carefully considers the many facets of such a phenomenon in its site-specific design to achieve a balanced outcome and optimise potential benefits.
The near-term benefits of successful water-sensitive design and planning are mostly local improvements such as better runoff quality and attenuation [2], whereas the long-term effects may be far-reaching. If done right, not only can ecosystems be protected from adverse impacts, but also regenerated to improve the ecosystem services that they provide to the local community [3] [4] [5].
Put in a wider context of the Water-Ecosystem-Energy-Food Nexus [6] in which ecosystems determine many of the inter-linkages, water-sensitive design and planning can play an essential role because nature-based solutions offer a key means to reconcile the competing interests between water, energy, food, and ecosystems. Nature-based solutions are an integrated approach that can reduce trade-offs and promote synergies among the four domains. They have demonstrated the potential to tackle both climate mitigation and adaptation challenges at relatively low cost while delivering multiple additional benefits for people and nature.
Adaptability
No single treatment system is efficient in removing all types of pollutant. Therefore, having a combination of solutions in the form of a treatment train can allow broader coverage and better adaptability.
Adaptable solutions can enhance the resilience of a site. They are typically characterised by having modular components, redundant capacities, and ease of implementation.
Modularity allows effective containment and limits the extent of damage should any part of a treatment system fails. Due to low inter-dependencies between the parts, it also facilitates transformation when the treatment system needs to adapt to changing conditions. Redundancy provides stability in the system, and ease of implementation makes modification and recovery faster.