Our biggest challenge in this new century is to take an idea that seems abstract – sustainable development – and turn it into a reality for all the world’s people. Rampant urbanization and climate changes have triggered severe and frequent natural disasters. Green infrastructure provides an opportunity to reassess how we manage and use green spaces through the identification and provision of interconnected green spaces that protect, manage and enhance environmental resources. Successful green and blue infrastructure planning is recognized as a natural solution and less expensive alternative to conventional 'grey' infrastructure that is environmentally friendly. As we are at the edge of climate change tipping points, integrating blue-green-grey infrastructure is a necessity to design sustainable and climate resilient cities.

1. Our biggest challenge in
this new century is to
take an idea that seems
abstract – sustainable
development – and turn it
into a reality for all the
world’s people.
Integration of Blue-Green-Grey Infrastructure

2. Prepared by – Deboline Mitra
Class – MPlan
Sem – 1st
Roll No. – MPLA04
Reg. No. – LV - 223841

3. Introduction
Rampant urbanization and climate changes have
triggered severe and frequent natural disasters. Adapting
to the escalating impacts of climate breakdown is the
need of the time. Green Infrastructure (GI) is a generic
term encompassing the protection, management, and
enhancement of urban, peri-urban and rural
environmental resources (natural and managed), through
the identification and provision of multifunctional and
interconnected green spaces and provides an
opportunity to reassess the manner in which we manage
and use green spaces.

4. Alternative to ‘grey’ infrastructure
Green and blue infrastructure is essentially the green
spaces and the available water environment. Successful
green and blue infrastructure planning is also recognised
as a natural solution and alternative to ‘grey’
infrastructure that is environmentally friendly and less
expensive. ‘Blue-Green’ infrastructure mixes the
conservation and restoration of nature with conventional
approaches resulting in fortifying communities against
climate effects. Nature can be used to provide important
services for communities by protecting them
against flooding or excessive heat, or helping to
improve air, soil, and water quality.

5. Economical Benefit
A study in 2012 that focused on 479 green infrastructure
projects across the United States, found that 44%
projects reduced costs compared to the 31% that
increased the costs. The most notable cost savings were
due to reduced stormwater runoff and decreased HVAC
cost.

6. Biodiversity
• We can address the problems that city infrastructures
cause for animal and plant movements in two ways:
(1) we can make corridors to better link habitat
fragments; (2) we can make urban habitats less
‘matrix’ and more of “mosaic” for more species,
through managing urban infrastructures and parks to
provide nesting, resting, and foraging sites for a
variety of animals, and leaving areas for wild plants
to establish.

7. Urban Heat Island
Urban Heat Islands (UHIs), together with urban noise and
urban air pollution, are three of the major environmental
challenges of future more liveable cities.
UHIs occur when the air temperature in urban area is
consistently higher than its rural area. While many causes are
attributable to the formation of urban heat islands such as
reduced evaporation, increased heat storage, increased net
radiation, reduced convection, stack effect induced by split
type air-conditioners and increased anthropogenic heat, the
contribution of each component strongly depends on the
individual city and its geography.

8. Baseflows and Groundwater
Recharge
• Urbanization increase impervious surface area reduces
infiltration and increases stormwater runoff.
• Decreased direct groundwater recharge is also the most
cited cause for lowered stream baseflow in urban streams.
• Urbanization can have other important impacts on
groundwater systems, each with consequences for streams.
These impacts have been divided into seven categories:
overexploitation; subsidence; saltwater intrusion;
contamination; changes in recharge and discharge;
alteration of the permeability structure; and destruction of
environmental resources, including wetlands and streams.

9. Precipitation And
Evapotranspiration
• Urban land use also influence the timing and magnitude of
precipitation inputs to urban watersheds. Urban induced
rainfall can be a result of the urban heat island effect.
• Urban surfaces are generally drier and release more heat
than surrounding rural areas. The urban heat island can alter
convection of air masses in urban areas. In addition, urban
surface roughness and the urban canopy (buildings,
infrastructure, or trees) can affect air circulation. The
presence of enhanced aerosols in urban areas may also
influence local climate.

10. Channel Geomorphology and
Sediment Transport
• Changes in land-cover associated with urbanization alter
surface and subsurface flow paths and the transport of water
and sediment to stream channels, which in turn can alter the
channel’s geomorphology.
• Increased runoff due to greater impervious areas and the
general decline in sediment yield following urbanization
resulted in urban channel erosion. In this case, it was shown
that urban channels tended to widen as a result of increased
peak flows and a reduction in sediment inputs.

11. Water Temperature In Channel
• Hydrologic and geomorphic changes as a result of
urbanization can have a direct impact on the thermal regime
of urban streams by changing the stream’s energy balance.
• Clearing of vegetation within riparian buffers reduces
channel shading, thereby increasing shortwave radiation
during the day and reducing Water longwave radiation
during the night.
• The temperature of a stream also change because discharge
of industrial or wastewater treatment effluents and from
heating of runoff that flows over impervious surfaces.
• Elevated temperature has been shown to enhance rates of
biological processes resulting in cascading changes to urban
stream ecosystems.

12. Nutrient Cycling & Retention
The trend of lower nutrient retentive capacity in urban streams
results from a combination of factors;
• Increased nonpoint source nutrient delivery through
stormwater conveyance systems and wastewater treatment
plant effluents
• Increased flashiness of stream hydrology resulting in
scouring of benthic sediments
• Disconnection between the stream and its riparian zone as
most of stormwater flow enters streams through pipes
• Channelization and clearing of woody debris which reduces
hyporheic (subsurface) flow through biologically active
sediments and removes organic sources for heterotrophic
microbes.

13. Indian Ground Water Statistics
• Annual rainfall of India 4,000 BCM & 1,137 BCM is
utilizable
• 690 BCM fills the surface water bodies & 447 BCM
percolate in ground
• Availability of groundwater is 447 BCM & 411 BCM
is accessible for extraction
• Annual use of 251 BCM ground water, India tops the
list of top 10 groundwater extracting countries
• By extracting 251 BCM, the nation exhausts a little
over 62% of the ground water resource annually.

14. Utilization of Ground Water In
India
• 65% of total irrigated land use only groundwater
• 85% of this came to be added after 1970
• The irrigated area increased from 6.5 million
hectares in 1951 to 65 million hectare in 2015
• 24 BCM supplies 85% of the country’s drinking
water
• 80% of Indians depend on groundwater for both
drinking and irrigation

15. Challenge & Solution
• Globally annual availability of freshwater is 7,600
CuM/capita
• Availability in India is 1,545 CuM (Brazil 41,865; us
9,802; China 2,060)
• Per capita water availability in India has shrunk by 70% in
last 50 years
• NITI AAYOG 2018 report - 21 major cities are likely to
run out of groundwater by 2020
• Rapid urbanization affecting natural groundwater recharge
& the only solution is rainwater harvesting
• Rainwater harvesting at roads is easy solution to increase
groundwater at urban areas along with reduction of urban
flooding

16. Roadside Drain Improvement
• To increase local ground water recharge and combat
seasonal flooding of roads, decentralization of storm-water
management needs to be integrated in roadway design.
• Conventional system - Storm water, silt & pollutants flows
directly into the drain which reduce capacity of drain &
convey pollutants to the natural drain.
• Decentralized system - Storm water flows to a bio-filtration
pit or bio-swale for temporarily retention, filtration &
infiltration to ground resulting slow flow to drain and finally
less polluted water to natural water-body or ground water.
For heavy rain situations, provision may be made to allow
storm water to overflow into the drain. MFZ with Tree Planting with an integrated Bio-swale
Conventional Approach – Storm Water flows directly into drain

17. Percolation At Median
• Percolation pits/trenches should be made as an integral part
of Median design to help infiltrate rainwater to ground
• It can reduce run-off and seasonal flooding.
• The area around the pits can be landscaped as shown above.
Percolation / Infiltration Trench in the Median
Typical Section of Percolation Trench

18. Existing Drain Retrofitting
• Percolation trenches should be made as an integral part of
Multi Functional Zone to help infiltrate rainwater to ground
• It can reduce run-off and seasonal flooding

19. Green Gutter At MFZ
• Green Gutter along the walkway or road edge trap pollutants
and delivers good water to sub soil surfaces
• It also play a major role in reducing urban heat-island effect
• It prevent dust re-suspension within ROW
• Green gutter must be long and continuous to effectively filter
pollutants
• FGL in Green Gutter must be 50-150 MM down from Top of
Road to retain water from road & pavement
• FGL in Green Gutter shall be 50-150 MM down from Top of
Pavement to retain water only from pavement
• Introduced in Ranchi Smart City & Rajkot Smart City
Existing MFZ & Proposed Green Gutter
Green Gutter
Kerbs for Green Gutter & Bio-planter
Existing Kerb & Proposed Kerb for Green Gutter

20. Bio-Planter
• Bio-planters are structured landscaped reservoirs filled &
planted with native water tolerant plants, rocks, soil etc.
• Infiltration bio-planters are suitable for areas with low water
table & permeable soil
• Flow-through bio-planters are suitable for areas with high
water table and non-permeable soil types
• Water tolerant vegetation like Canna, Pampas Grass, Spider
Lily etc. can be planted in bio-planters to remove variety of
pollutants by biological process
Flow-through bio-planter
Infiltration bio-planter

21. Bio-Swale
• Bio-swale has natural edges which are retained through
appropriate plantation and slope stabilization measure
• It sloped towards detention area to facilitate gradual
conveyance
• It is suitable for areas with low water table and permeable
soil type
• It uses bio-filtration media such as gravel, water tolerant
plantation, geo-textile etc. for proper filtration
• It can be part of ROWs & water can be retained for whole
year
Typical Bio-swale

22. Rain Garden
• Rain Garden has a bowl shape to collect rainwater runs off &
percolate the water to ground & Water can be retained
maximum for 48 hours resulting reduced volume of runoff
• Remove dirt, oil & metals from stormwater
• Plants recycle phosphorus and other nutrients
• Microbes in soils reduce bacteria levels in runoff
• Implemented within Ranchi & Rajkot Smart City and
BIDKIN utility plots and can be implemented in roundabouts
Rain Garden at Roundabout
Profile of Rain Garden
Rain Garden at Traffic Island

23. Xeriscaping
• Xeriscaping is the process of landscaping, or gardening, that
reduces or eliminates the need for irrigation
• It is promoted in regions where accessibility is less for
maintenance e.g., Medians, Roundabout etc.
• Plants used in Xeriscaping vary based on climate as this
strategy can be used in xeric, mesic & hydric environments
• Xeriscapes can reduce water consumption by 60% or more
compared to regular lawn landscapes
• Xeriscaping drastically reduce urban heat island effect in dry
areas
• Already implemented within Ranchi Smart City utility plots
Xeriscaping at Roundabout Xeriscaping at MFZ
Xeriscaping at MFZ

24. Permeable Pavement
• Permeable Paving system allows water to percolate into an
underlying soil or aggregate to store storm water
• Gradually the stored water infiltrated to Ground or removed
by an overflow drainage system
• It not only recharge ground water but also reduce pollutants
• Asphalt without fine particles create porosity
• Concrete without fine particles & special laying technique
provide permeable concrete
• Gaps between interlocking paver filled with permeable
material helps for water infiltration
• Open-celled paving grids provide almost 60% permeable
surface
Open-celled Paving
with Vegetation
Permeable Concrete Paver Open Cell Paver
Permeable Asphalt Interlocking Paver
Permeable Concrete Open-celled Paving
with Gravel

25. Integrated Road TCS
• With increase in green cover within roads and streets increase
demand of irrigation water
• Drip irrigation, use of recycled water & Xeriscaping is the
easy solution to reduce water demand
• New roads must design considering future widening &
accordingly drains & rainwater harvesting features need to
incorporate
• Location of infiltration units must be kept considering run-off
from roads reaches them first before entering to drain even
after road widening
Conventional Road Section
Proposed Road Section
Phase 1 of New Proposed Road Section

26. Medicinal Garden
• It is defined as a garden planted with the goal of serving the
needs of general health maintenance, as well as acute issues
that might arise. It has been implemented across utility plots
in Ranchi Smart City and Rajkot Smart City for the benefit of
the workers of the utility infrastructure along with local
people and animal kingdom.

27. Odour Control Garden
• Buffer plantation in multiple layers and heights with aromatic
plants to arrest the odour of STP and to attract birds and bees
resulting in improved air quality with mosaic for more urban
habitats.
• This green initiative successfully implemented at the STP of
Dholera Smart City, Ranchi Smart City & BIDKIN.

28. Cascading Roof With Garden
• It is one of the best solutions to increase green patches due to
lack of land for vegetation which can act against
fragmentation and insulator to buildings resulting in reduced
HVAC cost. Roof garden with cascading effect in large
buildings not only slows down rainwater run-off but also
increases absorption and filtration of rainwater while growing
food for the campus.

29. Vertical Garden & Topiary
• Vertical Garden is one of the main components in WOHA
style architecture to reduce glazing and metal facade resulting
in reduced reliance on mechanical cooling resulting in low
urban heat island effect and increased biodiversity by
attracting birds and insects. WOHA style buildings are largely
available in Singapore, and many are under construction in
Indonesia, Australia, Bangladesh, India & China. Topiary is
the older form of the modern age vertical garden spread from
Europe to far east countries in rooftop garden and ground
level for better aesthetic and defragmentation.

30. Reversible Infrastructure
• It can be rapidly converted to useful functions during
disasters, while serving as recreational infrastructure during
normal times.
• Water square is an example of integrated blue-green solution.
A conventional recreation plaza or play area with depressed
permeable surface can be utilised as catch basin during cloud
burst. It can provide for any unused area within the utility
plots.

31. Discussion
The biodiversity, diversity in life forms, suffers greater threat
from degradation, habitat fragmentation, spreading of invasive
species, indiscriminate use of natural resources, climate change,
pollution within aquatic environment and water flows.
Biological resources serve about 40 per cent of the world's
economy and nearly, 80 per cent of the needs of the people. It
provides greater opportunity in the field of medical, research,
education, and economic development. Declining biodiversity
is, therefore, a concern for countless reasons.

32. Conclusion
In the last two decades, many global cities, successfully
transformed their hard streets into porous and started creating
versatile and porous landscapes, albeit small-scale in informal
settlements mainly to resolve the issues of Urban Heat Island
effect and to conserve biodiversity.
As we are at the edge of the tipping point of climate change,
integration of Blue-Green-Grey Infrastructure is not just a
choice but a necessity of the time.
We need to design each aspect of green and blue infrastructure
for the project area, during the initial stages of engineering
design. Similarly, we need to start the activities of green and
blue infra development, while constructing the project
components.