Green infrastructure, groundwater and the sustainable city
2014 Fall Cyberseminar Series
- Larry Band / University of North Carolina
The management of water is among the most important attributes of urbanization. Provision of sufficient quantities and quality of freshwater, treatment and disposal of wastewater and flood protection are critical for urban sustainability. Over the last century, two major shifts in water management paradigms have occurred, the first to improve public health with the provision of infrastructure for centralized sanitary effluent collection and treatment, and the rapid drainage and routing of stormwater. A current shift in paradigm is now occurring in response to the unintended consequences of sanitary and stormwater management, which have degraded downstream water bodies and shifted flood hazard downstream. Current infrastructure is being designed and implemented to retain, rather than rapidly drain, stormwater, with a focus on infiltration based methods. In urban areas, this amounts to a shift in hydrologic behavior to depression focused recharge.
While stormwater is defined as surface flow resulting from developed areas, an integrated hydrologic systems approach to urban water management requires treatment of the full critical zone. In urban areas this extends from the top of the vegetation and building canopy, to a subsurface depth including natural soils, fill, saprolite and bedrock. In addition to matric and network flow in fracture systems, an urban “karst” includes multiple generations of current and past infrastructure, which has developed extensive subsurface pipe networks for supply and drainage, enhancing surface/groundwater flows and exchange. In this presentation, Band will discuss the need to focus on the urban critical zone, and the development and adaptation of new modeling and analytical approaches to understand and plan green infrastructure based on surface/groundwater/ecosystem interactions, and implications for the restoration and new design of cities.
CUAHSI's Fall 2014 Cyberseminar Series on Sustainable Urban Streams— Science to Support Evolving Management Objectives!
The management of urban streams and rivers has historically emphasized two critical ecosystem services: stormwater conveyance (flood protection) and wastewater disposal. Maximizing these services has generally resulted in major alteration of aquatic ecosystem structure and function, and reduced provision of other ecosystem services, such as aesthetics, recreation, food and biodiversity. Recent decades have seen a renewed appreciation of the value of these other services, an improved understanding of the processes by which streams are altered, and the development of engineering and design practices to manage these processes in ways that can provide multiple services.
Hosted by Seth Wenger, Director of Science of the River Basin Center at the University of Georgia