Selective Analysis of Blue Green Grid Use
What is a blue
green grid? This will essentially be two blog posts combined into one
comparative analysis.
A blue-green grid essentially is a series of management systems put in place by architects, landscape architects, and urban planners (or the savvy and thoughtful citizen) to allow cities to deal with water management in a more natural, well-paced, and controllable way. This is not going to be a system of concrete drain culverts that run into a giant BMP pond well out of sight of the city. These are going to be a series of smaller systems such s rain gardens, micro parks, detention plantings, green roofs, and the like that allow for water to be dealt with at a smaller scale, closer to the source. this is the way that water is naturally managed by the earth, and the modern city's vast areas of gray infrastructure have made this sort of water management a distant idea and impossible fantasy in the minds of many urbanites. This is not the case everywhere, however. cities such as Amsterdam and Portland have seen large-scale policies and actions to adopt the aforementioned strategies for the betterment of their environments and subsequent quality of life for humans and nature within their bounds. This sort of thing does not have to happen at the scale of the city, either, there have been smaller-scale communities that practice the above strategies, and in smaller communities, even more radical strategies such as natural water filtration and recycling have been employed. So let's talk about a few specific examples of this that could serve as a brief case study into the importance of these strategies in the future of city and community planning.
The first project that I would like to discuss is one that
I have heard a great deal about over the last few years from a professor I
became close with, Cory Gallo, who worked in close proximity to its
development during his time at Greenworks Portland, Tanner Springs Park in
Portland, Oregon. It was designed by Atelier Dreiseitl, a renowned German
firm, in collaboration with the aforementioned local firm. The project's
ideology is to "manage water and stormwater while creating a refuge for
people and wildlife in the midst of a bustling downtown
neighborhood". I believe that the location of this incredible park/
piece of blue-green infrastructure in such a dense area speaks to the
possibility of natural solutions within the urban fabric, and serves as a
surprising educational moment to that point. The project was completed in 2005,
and it is a wonder that it did not inspire more widespread use of its tenets
based on how seemingly successful the project is.
Tanner Springs Park is a project that manages water runoff (260
cubic meters) from surrounding impervious streets and lots in the fashion that
the site would have naturally managed watershed runoff prior to the
industrialization of the area by creating a restored wetland that behaves as
true to native ecology as possible within a programmed space designed for human
interaction and participation. the pond has a deep point of almost two meters,
with all corners of the site sloping into it. the site is also bordered by an
undulating, wall of recycled rails that I believe conceptually speaks to the
restorative, pervious, and natural-from-the-unnatural notions that frame the
project as a whole.
The plantings
selected for the project were all native and resilient to wetland conditions.
They are all native to the Williamette Valley, many being wetland sedges and
Oregon white oaks that reinforce both the ideas of natural systems within the urban
and wetland resiliency in a location that in modern American planning would
usually not conceive as an option to have. the site shows water movement
outside of storm events with a bubbling spring that runs from the top of a
meadow hill, down into that previously discussed low point within the pond.
Natural seeming, undulating, and momentarily hidden walking paths lead the
visitor through these natural conditions, becoming more biophilic as the
visitor leaves the concrete seat wall to one side or street sidewalks on the
other into the grassy wetland at the heart of the site. The site truly does
show visitors the possibility of having a living ecology within the urban
environment. This project is a huge first stepping stone into convincing the
public that these things are possible to weave into all future urban fabrics.
.jpg)
A second
project dealing with Blue-Green planning ideologies that I believe is a
worthwhile first look into this theme for someone is the Water Factory
[waterfabriek] at the Emmen Zoo in, you guessed it, Emmen, the Netherlands
[nederland]. This undertaking is more similar to some of the other previous
entries into this blog about living machines for water recycling and treatment,
if you are so inclined to check that out as well. the project was designed by
Waterleidingmaatschappij Drenthe [a mouthful for we Americans I'm sure, I won't
try to pronounce it, but their work is rock solid.]. It was completed around
the same time as Tanner Springs Park, in 2002, and has become a great addition
to its environment both in a utilitarian function, as well as an educational
one for both locals and tourists. It is open to the public and shows the
process of recycling, in an almost closed system, the wastewater to its
visitors.
Its process
of water recycling comes from its living machine: a hothouse with tropical
plants that naturally reuse and treat unsafe water. This living machine has
reduced the amount of drinking water pulled from off-site from 180,000 cubic
meters to 30,000 cubic meters annually. This is because instead of using
potable water from off-site, the recycling of existing water allows for on-site
water to be reused for toilets, maintenance and cleaning, and filling
water basins for simi-aquatic animals.
The process of
water treatment is cleaned by membrane filtration through biological methods of
bacterium and plant roots. The water is also forced through small tubes that
filter out harmful sediment and microbiological life, while leaving a substance
they call "activated sludge" for the plants in the hothouse tanks to
feed on. The tropical plants roots use the nutrients from the waste impurities
in the "activated sludge" [mostly nitrogen and phosphorus]. On these
roots, microorganisms that take care of most of the rest of the harmful
impurities thrive and are sustained. This is a full symbiotic ecosystem taking
place in the living machine tanks. The tanks are finally treated with UV light
from the sun and then given one last pass through a UV purifying machine before
it is deployed back out into the zoo for use. The only drawback to this
system, as is a problem with many other water treatment alternatives and living
machines is energy consumption, so if clean energy sources such as solar or
wind could be used in areas with living machines, the process could be feasible
at larger scales and at more sustainable efficiency.
To
conclude, systems like the living machines, stormwater basins, and urban
naturally restored wetlands can all play a key factor in the education,
implementation, and realized role that blue-green grids and infrastructure can
play in the future of a sustainable city or community. The methods can be
placed into the foundation of community planning to make our communities both
more healthy for us, and less of a strain on the environment that they leech
off of. We can use these systems to lessen our footprint and form a more
symbiotic relationship with our ecosystems. These systems are not perfect yet,
but through engagement, funding, and education, we can build on these
foundations to craft a more thoughtful future for human communities.
Comments
Post a Comment