Conventional vs. Progressive Stormwater Management:

Fusing Environment, Art and Stormwater Management
The ‘new’ emergence of Green Infrastructure is really not so new but is experiencing a surge in the practice of Landscape Architecture and Civil Engineering. Green Infrastructure is a growing field that marries practical and functional stormwater management practices with an environmentally sensitive approach that makes it more sustainable than what I refer to as Conventional Best Management Practices (BMP) and at its best infuses art and an artful eye for greater aesthetic appeal and cultural strength.

Green Infrastructure, also known as Low Impact Development (LID) and Artful Rainwater Design (ARD), strives to replace and mimic natural processes lost in construction while creating beautiful and socially functioning landscapes. Conventional BMP, which are often termed as “Gray Infrastructure”, allows for little creativity and is largely pipe, cobble and gravel intensive in its construction. The Green Infrastructure approach does not disregard conventional BMP as its tools are still of value in situations where Green Infrastructure is infeasible due to space or other considerations. The difference between conventional BMP and Green Infrastructure, ARD and LID is that the later approaches take on a more environmentally sound and sustainable aspect. The restoration, rehabilitation and enhancement of natural systems are key elements to the success of Green Infrastructure and LID. ARD really brings focus the creative aspect integrating artistic values and artistic elements into the mix.

Borrowing from the book Artful Rainwater Design by Stuart Echols an Eliza Pennypacker, two general components of ARD help define goals for the management of stormwater: Amenity and Utility. While each of these has specific goals, the outcomes of management techniques utilized may serve multiple purposes. ‘Amenity’ refers to the potentials for elements of Education, Recreation, Safety, Public Relations and Aesthetic Richness. ‘Utility’ refers to features that serve in Reduction of pollutant loads, Reduction of damage from runoff and erosion, Safely moving, controlling and containing water, Capture and Reuse for landscape and other uses, and finally Restoration and Creation of Habitats – plant, wetland, fish and wildlife. These are especially important aspects of the mountain environment.
In the Mountain Environment, it is important to understand that stormwater management pertains to two types of stormwater. In mountainous regions our water management issues are two fold; one, the bulk of precipitation and water supply comes in the form of snow – usually lots of it – typically between the months of October and March which is often supplemented by spring rains; and two, flashy summer afternoon monsoon driven thunderstorms that can deliver very large quantities of water and cause temporary flooding of low lying areas in a very short period of time. Winter snows will generally melt rapidly as the spring warms picking up loose sediment and road sands with the potential for seriously degrading the water quality and habitats of our lakes and waterways. Summer thunderstorms can create broad scale damage particularly where unstabilized disturbed soils are present.

Until fairly recently the solution to this problem has been to turn to diverting water to localized storm drains into pipes that release that water into local waterways and in some communities into sewage treatment plants. More often than not that water is polluted with suspended sentiments, eroded soils, chemicals and other waste. More lately the practice of diverting stormwater to cobble lined swales and retention basins or gravel filled drywells and infiltration trenches has become very common. This form of BMP is also referred to as Gray Infrastructure. So my question is, “with all that gravel and cobble, how much grayer can you get?” The one good thing about this practice is that it generally serves to keep stormwater on site rather than let it run into drainage systems that deposit into sewer systems or local water bodies and serves to help infiltrate it to help recharge groundwater.
The drawbacks lie in that there is no use of vegetation to help facilitate natural processes including evapotranspiration, nutrient and chemical uptake, and more rapid infiltration. Additionally, this practice typically routes large concentrated volumes of stormwater through large pipes to large basins where water sits for long periods exacerbating vector and other safety related problems. LID features are typically smaller and shallower features placed throughout an area of development, rather than at a single location, spreading stormwater more evenly resulting in potential for more efficient infiltration and reduced risk of mosquito infestation while greatly improving on aesthetics.
I have come to believe, and tried to encourage communities, clients and co-consultants, that there are more aesthetically pleasing and more functional ways to manage water than conventional BMP and sometimes I wonder about the term “Best”. The Green Infrastructure, LID and ARD practices are typically more sustainable in that they require less in the way of mined and imported materials, require little maintenance, call on natural systems to manage water and foster a more ecological balance.
Green infrastructure, LID and ARD provide us with the opportunity to not only restore and take advantage of natural systems, as well as create new habitat, it also gives us latitude to imbue creativity, yes and even art, into solutions that would normally be devoid of such. Functional elements that facilitate these practices may be designed to also function as art work which enriches the users’ experience of the system. This greatly improves on the social and cultural aspects of what is done in our environment.
In my practice I have chosen to group these concepts of stormwater management practices into what I call Progressive Stormwater Management, or PSM, because I firmly believe that working sustainably and artfully with nature in management of stormwater is truly progressive.
To finish, Progressive Stormwater Management has local and global implications as societies move forward in their occupation of the planet. Ian McHarg, a renowned landscape architect who authored the 1969 book Design with Nature, was very progressive in his beliefs and teachings on the subject said, “let us green the earth, restore the earth, heal the earth…” Somehow along the way we lost sight of this idea and I believe we are coming back around to it through PSM.
Please visit my website for more on Progressive Stormwater Management.