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Report 1 (of 6): Rooftop Revolution
- Russia
Introduction
St Petersburg in Russia, like all modern cities,
has to cope with mountains of domestic waste. Its
six million inhabitants have also experienced food
shortages and many hardships over the past decade.
But now a scheme to turn rooftops into gardens and
waste into compost means that residents can grow their
own fresh food.
Economic problems, pollution from heavy industries,
lack of funding for environmental improvements and
political unrest mean that conditions are poor for
the inhabitants of St Petersburg. The life expectancy
of men and women is far below European averages and
up to 60 per cent of household income is used for
food. St Petersburg alone produces 12,000 cubic metres
of rubbish, which requires 3000 trucks for removal
beyond the city borders. Most of this garbage comes
from households.
Driven originally by a desire to improve the city
environments, the St Petersburg Urban Gardening Club
started to transform rooftops into valuable gardening
space in 1993. In Russia most people in larger cities
live in buildings with huge sturdy rooftops constructed
to withstand heavy falls of snow. They also typically
have very limited access to land. The scheme aims
to give people access to gardens so that they can
produce vegetables for their own consumption or to
sell in the local market.
Turning Roofs into Growing Gardens
There are approximately 15 rooftop gardens and 100
participants in St Petersburg. The European
Union (EU) provides funding, while a local organisation,
Centre for Citizens Initiatives (CCI), provides consultations
and teaching seminars, and furnishes technical and
material assistance to urban residents and institutions
that create rooftop gardens. Last but not least, community
members build and manage the gardens themselves.
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A rooftop garden in St Petersburg
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Theoretically, any roof surface can be greened - even
sloped or curved roofs can support a layer of sod or
wild flowers. It depends on how the garden is to be
used, what the gardeners want to grow, and how often
they will need to access the roof. A flat roof, approximating
level ground conditions, is easy to work with.
One of the apartment blocks where the scheme has
been introduced is cooperatively owned. Brick-built,
with nine storeys, it houses 267 apartments with 540
residents, 60 per cent of whom are pensioners. It
produces 200 kilos of food garbage daily in winter
and 300 kilos in summer. The house has a flat roof
of 1700 square metres, and 600 square metres of cellar.
People living in the apartments compost their household
waste in the cellar, recycle all other waste where
possible, and then use soil on the roofs to grow vegetables.
While individuals own their apartments, the government
owns the stairways and the rooftops. Permission is
needed to use the rooftop in case of concerns about
damage caused to the waterproofing by footfall. A
surface has to be constructed to minimise this.
Technical Guidelines to Rooftops
and Gardens
Does the roof garden increase the risk of water
leakage or damage to the roof?
No. In fact, planting beds/surfaces can protect
and insulate roofing systems. The following guidelines
will help to avoid any potential problems.
- A protective drainage layer between the soil and
the membrane under planting beds, and raised surfacing
treatment for non-planted areas, are measures that
should avoid damage if the waterproof membrane is
not protected from point loading, shovels, shoe
heels, and dropped equipment.
- Ensure that the roof drains have the proper covers,
and that planters are lined with a layer of filter
cloth and gravel to keep the soil from draining
out with the water. Often a layer of filter cloth
or drainage mat is laid over the whole roof, just
on top of the waterproofing, to avoid this problem
- especially if there is the likelihood of soil
being spilled from planters, or sand removed from
sandboxes. Otherwise, the roof drainage system may
become clogged with sand, soil or vegetation, causing
water to sit on the roof for long periods of time,
allowing it to either break down the membrane or
work its way through the seams. (Some waterproofing
systems are designed for holding water, others are
not.)
- If leachate from plants, fertilisers, and/or composters
comes in contact with certain roofing membranes,
it may lead to membrane breakdown. If you find that
the existing membrane is not compatible with these
chemicals and organic compounds, the containers
and planters could be lined with a continuous membrane,
or placed on overflow trays; composters should never
sit directly on the membrane because of their requirements
for aeration and turning/working.
It may be difficult to locate and access a leak after
the garden is in place. Movable planters/containers,
modular walkways/surfacing treatment and compartmentalised
planting beds could solve this problem.
How can rainwater falling on a site be used most
effectively?
Slow down the flow of water to enhance absorption
by texturing, terracing, planting and ensuring permeability
of surfaces, especially on slopes (which should be
as gradual as possible). Direct the flow of runoff
to planted areas and retention areas so that as much
water as possible can be retained on the site. Do
not direct water to inlet drains unless essential
due to weight limitations or inadequate waterproofing.
Retain and store rainwater in a covered reservoir/cistern
for later distribution to plants (watering by hand
or by a 'leaky pipe' irrigation system). Ideally,
runoff could be directed to a subsurface reservoir
to provide water to plants on an 'as-needed' basis.
What issues are important in the design and construction
of the rooftop garden?
- Occupant load (i.e. the number of people occupying
the garden) as it relates to and impacts on
- structural loading requirements
- exit requirements
- Exit requirements
- types of exits allowed and number of exits
required
- distance between exits and travel distance
to exits
- sizes of exits and areas defined as 'access
to exits'
- fire separations between exits and the rest
of the floor area
- possible requirements for fire alarms, exit
lights, emergency lighting
- Access for people with disabilities and barrier
free design
- Requirements for enclosures, i.e. guards, railings,
parapets, walls around rooftops, terraces, and balconies
- required heights
- the placement of elements such as planters
adjacent to enclosures which may reduce their
effective height
- climbability of enclosures
- loading and structural stability of guards
and railings
- Specific requirements for structures/buildings
on roofs, relating to
- effect on overall building height
- fire rating of structural parts
- exit arrangements
- Other applicable issues might include
- possible modification of window washing anchors
on the roof
- possible upgrading of washroom and service
requirements
- possible upgrading of drainage and waterproofing
requirements
Structural considerations of rooftop gardens
There is the new loading exerted by the garden
(the size and distribution of which can be changed
by altering the layout of the garden) and there is
the load-carrying capacity of the structure (which
can be enhanced by increasing the strength of the
building's existing load-bearing parts or by adding
new ones). When designing a roof garden consult a
licensed engineer regarding the load-carrying capacity
of the building you are working with and ensure that
the garden design and the structural capacity are
compatible.
(Source: City Farmer)
The growing season lasts from mid-May to mid-September
in Russia and leafy greens, potatoes, tomatoes, etc
are predominantly grown in thin beds of 4 to 8 centimetres
on the rooftop.
Separate containers for different kind of waste are
built and installed. Residents are instructed about
the need for and benefits of separate collection of
garbage. Food waste is collected separately; up to
100 kilos of rotting vegetables are taken to the basement
each week and pulped. The space in the cellar is modified
for processing food garbage into compost with the
help of red worms. Soil mix is critical because they
cannot use organic matter from polluted city lawns
and parks. When tested for heavy metals, vegetables
from rooftop gardens had lower levels of metal contaminants
than vegetables bought from city markets.
A bed is made with moistened newspaper in perforated
plastic containers and 500 grams of worms, household
vegetable waste and a sprinkling of peat moss and
chalk are added to give the correct chemical balance.
Finally, ground-up eggshell is used to absorb the
moisture and give trace calcium before the container
is covered. Once a week, 2 kilos of waste is added
to each container and after two or three months the
fertiliser is ready. The worms and their eggs are
extracted and put to work in a new container.
Compost is used on the plot around the house for
growing trees, bushes and flowers and on the roof
for the rooftop garden. Excess compost may be used
for production of soil for house plants, and this
has a potential for becoming a small business.
Looking to the Future
The club has expanded its activities, setting up
a vegetable garden in a prison in St Petersburg, providing
both food and activities for the inmates. In 1998
a therapy garden was established in an artificial
limb institute, providing invalids with a form of
rehabilitation and basic knowledge of agriculture.
A garden on top of a primary school is acting as a
venue for children to integrate lessons with practical
learning.
Project participants have taken part in city exhibitions,
created an on-line rooftop gardening guide in Russian
and published a book on the subject. Plans are in
place to continue promoting the scheme and using the
project as a model for others to learn from and replicate.
CCI is managing a programme for sponsors to make donations
and directly support a rooftop garden in St Petersburg.
Residents can apply for funding for rooftop gardens
and are selected by CCI on the basis of having a solid
plan for developing their rooftops into productive
gardens.
| Green roofs reduce the 'urban
island' effect whereby cities absorb and produce
excess heat. Plants absorb CO2 emissions and
improve the air quality, while also absorbing
heat and causing a cooling effect. Green roofs
insulate buildings and this can reduce energy
costs by 10-20 per cent, thereby lowering the
production of greenhouse gases.Green roofs can
retain rainwater and generally use much less
water for irrigation of plants. They may retain
50 per cent of winter precipitation that falls
on them, and up to 100 per cent in the summer
months. Pests and
diseases may be more easily controlled in
urban gardens without the use of chemical
pesticides, because they can be more easily
and quickly dealt with. The lifespan of the
roof may actually be lengthened with vegetative
cover, as it protects the roof membrane from
ultra-violet rays and temperature fluctuations.
(Source: Greening Rooftops in the Garden City) |
The environmental, economic and social benefits of
rooftop gardening are considerable. The scheme promotes
community ownership and cooperation. It creates an
outdoor green space and provides an opportunity for
people to interact and build links between residents,
to develop new skills and to take responsibility for
managing a cooperative.
Its primary function is to support urban food production,
increasing fresh food supply to residents, especially
low-income people and pensioners, and reducing household
expenditure on food. It can create one or two jobs
and a source of income, add value of buildings for
owners and tenants alike, and create favourable conditions
for potential small businesses. The amount of solid
waste is reduced through conscientious consumption
and recycling. Costs of transporting food are minimised.
"This co-operative has reduced waste
collection expenses by 30,000 roubles per year. That
means every month we recycle 500 kilos of household
rubbish right here without taking it anywhere. If
every building and family in the city did the same
imagine how much cleaner the big cities like ours
would be." Invw Alla Sokol, community member.
Research that has been conducted shows that the potential
of rooftop gardening is huge. For example, in just
one district (St Petersburg has 12) it is possible
to grow 2000 tonnes of vegetables. Institutions such
as orphanages, hospitals and schools as well as apartment
blocks have participated in creating rooftop gardens
in Russia to improve nutrition, increase their food
security and contribute to the improvement in local
environment and quality of life.
Further Information
Articles on Project in St Petersburg
Urban Agriculture Notes Rooftop Gardening in St Petersburg,
Russia by Alexander (Sasha) Gavrilov
http://www.cityfarmer.org/russiastp.html
St Petersburg Sustainable Urban Community Development
Project description
www.geocities.com
Centre
for Citizens Initiatives
General Articles
Greening
Rooftops in the Garden City by Heather Hobbs - report
on state of rooftop gardening world-wide
http://www.cityfarmer.org/rooftop59.html
Contains useful general technical information on rooftop
gardens
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