As Southern California continues to grapple with drought (following the gradual deflation of hope for relief from this year’s non-El Niño event), as a landscape architect, I find myself thinking again about additional measures we can implement locally to preserve and protect resources which are vital to sustaining a healthy and viable environment: protecting important and iconic trees (many now plagued by secondary pest infestations), enacting soil conservation to combat losses due to lack of vegetated covers, and putting a moratorium on tapping already dwindling water tables from pumping.
Furthermore, a continuing drought can possibly be indicative of global warming trends – temperature extremes, deviations from precipitation pattern norms, storms with more energy – which, paradoxically, force us to prepare for droughts’ extreme opposites: street flooding, siltation and erosion of streams, and excessive pollution entering our water bodies.
As a society, I feel that many environmental issues reflect our convenient and pervasive view of the environment as being ‘out there’ – isolated and disjointed elements…problems separate from us, rather than the environment as an integrated, living system of plants, soils, microbes, hydrology, and animals, that include us. A shift in understanding our part and participation in the environment as a functioning system is critical to our success in addressing these complex issues, and includes looking to the environmental systems themselves for answers.
I often think the most successful landscape designs mimic nature. Within the water use reduction forum – while local and state-mandated measures have provided significant gains – I believe the implementation of more green streets as an addition to and component of our urban infrastructure system can greatly assist in conserving water and other important resources while mitigating potential global warming issues, such as increased flooding. A system of linked stormwater ‘best management practices’ that capture, clean and store water, Green Streets minimize environmental impacts locally the larger environment as well.
In addition to being effective, many of these systems are an extension of relatively simple natural systems: rain barrels, rain gardens, vegetated swales, permeable pavers, native and adaptive plant material tolerant of both drought and periodic flooding. Water can be stored for passive or pumped re-use, vegetated swales slow water and aid in soil retention; vegetated right-of-way infiltration areas can infiltrate water and filter impurities; infrastructure to underground infiltration galleries can hold water for slow dispersal to replenish adjoining water tables. Typically sized per municipal standards, many communities and urban centers around the country and world have and are installing green streets (or green infrastructure components) to address issues of flooding, pollution uptake, water conservation, and water infiltration as aging, engineered systems fail or can no long achieve results in line with changing needs.
Building Green Streets involves communities. From your neighbors’ rain barrel to the street’s vegetated infiltration swale, there is an exposure and visualization of both resource components and the linkage between them: water, soil, plants, animals. These components – which define and link the neighborhood – provide community building through resource preservation and declare a conscious movement away from car-based thinking to giving streets back to pedestrians: a green, community, synergistic, and living-system effect.