2016 Ozone Research and Applications (India) Pvt. Ltd., Nagpur [REJUVENATION OF HAUZ KHAS TANK ] This report focuses on the current scenario of the Hauz Khas Tank and aims to propose an action plan for its rejuvenation as an aesthetically pleasing heritage site it was ages ago.
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2016
Ozone Research and Applications (India) Pvt. Ltd., Nagpur
[REJUVENATION OF HAUZ
KHAS TANK ] This report focuses on the current scenario of the Hauz Khas Tank and aims to propose an action
plan for its rejuvenation as an aesthetically pleasing heritage site it was ages ago.
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ACKNOWLEDGEMENT
We are grateful to Engineers India Limited for bestowing us with the
opportunity of draft ing this report. The task would not have been possib le
without their guidance and technical expert ise. We would especia lly l ike to
thank Mr. Ashwani Soni (Director-Projects) and Mr. Sanjoy
Mukherjee (General Manager-Infrastructure) for giving us the
motivation in preparing this report. We would also l ike to thank the local
authorit ies at Hauz Khas who provided us with a lot of ground details . We
are thankful to AES Laboratories, New Delhi for conduct ing the tests as
per the standard norms. We would also l ike to acknowledge the efforts of
al l those who have contributed to this report in some way or the other.
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EXECUTIVE SUMMARY
This report makes an effort to look into the current state of Hauz Khas
Tank at Deer Park, Delhi and aims to propose an action plan for the
rejuvenation of this historical s ite. Chapter 2 brief ly describes the impact
of urbanization on lakes and the effects and causes of subsequent
eutrophication. Chapter 3 focuses on the location, current state of the
Hauz Khas Tank, init ial observation about the water body and source of
tank water. Chapter 4 deals with the basic design of the tank,
meteorological data and the water quality analysis of the tank. Chapter 5
aims at proposing an appropriate methodology to rejuvenate the Hauz
Khas Tank with design concept and proposal. Chapter 6 gives a rough
est imat ion about the Capita l Investment required to implement the
proposed plan. Chapter 7 summarizes the report. Chapter 8 ment ions the
references used in draft ing the report. Chapter 9 is an appendix
compris ing of the Lake Water analys is carr ied out by AES Laboratories,
New Delhi.
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TABLE OF CONTENTS
Pages
Acknowledgement 1
Executive Summary 2
1. Introduction 6
1.1. Orig in of The Report 6
1.2. Purpose 6
1.3. Sources and Methods of Collecting Data 6
2. Impact of Urbanization and Eutrophication on Lakes 7
2.1. Effect of Urbanizat ion on Hydrology 7
2.2. Eutrophicat ion 8
2.2.1. Eutrophicat ion- Causes 9
2.2.2. Eutrophicat ion- Effect on ecology, aesthetics and
human health 10
3. Hauz Khas Tank- Existing Scenario 13
3.1. Locat ion and Brief History 13
3.2. Tank Source and Restorat ion 16
3.3. Hauz Khas Tank- Today 20
4. Basic Design Data of Hauz Khas 22
4.1. Introduction 22
4.2. Meteorological Data 22
4.3. Water Qual ity Analys is Report 23
4.4. ORAIPL’s Take on the Analys is 24
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5. Design Concept and Proposal 26
5.1. Background 26
5.1.1. Design Basis 26
5.1.2. Desired Product Water Quality 26
5.2. Design Concept and Strategy Proposed 27
6. Capital Investment for the Proposed Plan 31
7. Conclusion 33
8. References 33
9. Appendix- AES Lab Report 34
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1. INTRODUCTION
1.1. Origin of the Report
This report has been compiled and prepared by Ozone Research and Applications (India)
Pvt. Ltd, Nagpur. This report analyzed the existing scenario of the historical Hauz Khas
Tank at Deer Park, New Delhi and aimed to propose a treatment methodology to
rejuvenate and sustain the heritage value of Hauz Khas.
1.2. Purpose
The historic Hauz Khas Tank has been a prime tourist spot since ages but has recently
lost its aesthetic value to the eutrophication of the lake leading to algal bloom, color,
smell and water treatment problems. An urgent need was felt to address the issue and
take immediate action for the revival of this historical place as the water quality seems
to be deteriorating by every passing hour.
1.3. Sources and Methods of Collecting Data
The primary source of collecting information was the internet, site visit and water
analysis under the esteemed guidance of the workforce at Engineers India Limited, New
Delhi and also Mr. Vishal Waindeskar, Director, ORAIPL.
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2. IMPACT OF URBANIZATION
AND EUTROPHICATION ON
LAKES
2.1. Effect of Urbanization on Hydrology
Humanity is increasingly urban, but continues to depend on Nature for its survival. Cities
are dependent on the ecosystems beyond the city limits, but also benefit from internal
urban ecosystems. The numerous effects of urbanization on hydrology, geomorphology,
and ecology make wetlands in urban regions function differently from wetlands in non-
urban lands. Furthermore, wetlands in urban regions may take on human-related values
that they lack in nonurban areas, as they provide some contact with nature, and some
opportunities for recreations that are otherwise rare in the urban landscape. Natural
water bodies tend to get absorbed in urban expansion and their catchment is disturbed
as a result of development. In Delhi in the Yamuna floodplain, the once river fed water
bodies are disconnected from the river because of embankments.
The biodiversity of lake and pond ecosystems is currently threatened by a number of
human disturbances, of which the most important include increased nutrient load,
contamination, acidification, and invasion of exotic species (Bronmark & Hansson, 2002).
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Hydrologic change is the most visible impact of urbanization. Hydrology concerns the
quality, duration, rates, frequency and other properties of water flow. Urbanization
typically increases runoff peak flows and total flow volumes and damages water quality
and aesthetics. Pollutants reach wetlands mainly through runoff. Urbanized watersheds
generate large amounts of pollutants, including eroded soil from construction sites, toxic
metals and petroleum from roadways, industrial and commercial areas, and nutrients
and bacteria from residential areas. By volume, sediment is the most important non-
point pollutant. At the same time that urbanization produces large quantities of
pollutants, it reduces water infiltration capacity, yielding more surface runoff. Pollutants
from urban land uses are, therefore, more vulnerable to transport by surface runoff than
pollutants from other land uses. The urbanization effects on wetland hydrology are:-
• Decreased surface storage of storm water which results in increased surface
runoff
• Increased storm water discharge relative to base flow discharge which results in
increased erosive force within stream channels, which in turn results in increased
sediment input to recipient waters ‚
• Changes in water quality (increased turbidity, increased nutrients, metals, organic
pollutants, decreased O2 etc.)
• Decreased groundwater recharge which results in decreased groundwater flow,
which reduces base flow and may eliminate dry season flow
• Increased floodwater frequency and magnitude result in, or scour of wetland
surface, physical disturbance of vegetation
• Increase in range of flow rates (low flows are diminished high flows are
augmented) may deprive wetlands of water during dry weather
2.2. Eutrophication
“Eutrophication is an accelerated growth of algae on higher forms of plant life caused by
the enrichment of water by nutrients, especially compounds of nitrogen and/or
phosphorus and inducing an undesirable disturbance to the balance of organisms present
in the water and to the quality of the water concerned”.
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2.2.1 Eutrophication – Causes
The mechanisms that lead to eutrophication, i.e. to this new status of the aquatic
environment, are complex and interlinked. The enrichment of water by nutrients can be
of natural origin but it is often dramatically increased by human activities. This occurs
almost everywhere in the world. There are three main sources of anthropic nutrient
input: runoff, erosion and leaching from fertilized agricultural areas, and sewage from
cities and industrial wastewater. Atmospheric deposition of nitrogen (from animal
breeding and combustion gases) can also be important. According to the European
Environment Agency, “the main source of nitrogen pollutants is run-off from agricultural
land, whereas most phosphorus pollution comes from households and industry, including
phosphorus-based detergents. The rapid increase in industrial production and in in-house
consumption during the 20th century has resulted in greater volumes of nutrient-rich
wastewater. Besides nutrient inputs, the first condition supporting eutrophication
development is purely physical - it is the containment (time of renewal) of the water.
The containment of water can be physical, such as in a lake or even in a slow river that
works as a batch (upstream waters do not mix with downstream waters), or it can be
dynamic. Other physical factors influence eutrophication of water bodies. Thermal
stratification of stagnant water bodies (such as lakes and reservoirs), temperature and
light influence the development of aquatic algae. Increased light and temperature
conditions during spring and summer explain why eutrophication is a phenomenon that
occurs mainly during these seasons. Eutrophication itself affects the penetration of light
through the water body because of the shadow effect coming from the development of
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algae and other living organisms and this reduces photosynthesis in deep water layers,
and aquatic grass and weeds bottom development.
2.2.2 Eutrophication – Effects on Ecology, Aesthetics and
Human Health
The major consequence of eutrophication concerns the availability of oxygen. Plants,
through photosynthesis, produce oxygen in daylight. On the contrary, in darkness all
animals and plants, as well as aerobic microorganisms and decomposing dead
organisms, respire and consume oxygen. These two competitive processes are
dependent on the development of the biomass. In the case of severe biomass
accumulation, the process of oxidation of the organic matter that has formed into
sediment at the bottom of the water body will consume all the available oxygen. Even
the oxygen contained in sulphates (SO4 2-) will be used by some specific bacteria. This
will lead to the release of sulphur (S2-) that will immediately capture the free oxygen
still present in the upper layers. Thus, the water body will lose all its oxygen and all life
will disappear. This is when the very specific smell of rotten eggs, originating mainly
from sulphur, will appear.
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An infestation of water hyacinth (Eichhornia crassipes) can be a health hazard. It can
provide an ideal breeding habitat for mosquito larvae and it can protect the snail vector
of bilharzia [Scott et al., 1979]. Of all the cyanotoxins currently known, the cyclic
peptides represent the greatest concern to human health, although this may be because
so little is known about the other cyanotoxins [Chorus and Bartram, 1999]. The concern
exists primarily because of the potential risk of long term exposure to comparatively low
concentrations of the toxins in drinking water supplies. Acute exposure to high doses
may cause death from liver haemorrhage or liver failure. Other short term effects on
humans include gastrointestinal and hepatic illnesses. A number of adverse
consequences have been documented for swimmers exposed to cyanobacterial blooms.
Chronic exposure to low doses may promote the growth of liver and other tumours.
Nevertheless, many cyanobacterial blooms are apparently not hazardous to animals
[Carmichael, 1992]. It is also possible that people exposed to odours from waterways
contaminated with decaying algae of cyanobacteria may suffer chronic ill-health effects.
The existence of large areas of macrophytes can inhibit or prevent access to waterways.
This decreases the fitness for use of the water for water sports such as skiing, yachting
and fishing. The presence of unsightly and smelling scums also makes any recreational
use of the water body unpleasant.
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The condition of urban lakes and water bodies in India is so dismal that the people have
now filed a number of public interest litigation (PIL) to put pressure on government
agencies to take action for their conservation. Citizens having realised that this
important natural resource is key to sustenance of habitations and source of potable
water need immediate conservation. Many cases have been documented, Dal Lake in
Kashmir, Delhi’s Waterbodies, Kurpa Tal, Naini Tal, Bhimtal, Naukuchia Tal and Sattal in
Uttaranchal, Charkop, Thanne lake, Powai and Eksar Lakes in Mumbai, Hussain Sagar,
Saroo Nagar lake, Kolleru wetlands in Andhra Pradesh, Vembanad wetlands in Kerala,
Bangalore lakes, Bellandur lake in Karnataka etc. There are many more instances where
citizens have come forward to conserve the wetlands and lake in light of government
apathy.
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3. Hauz Khas Tank-Existing
Scenario
3.1. Location and Brief History
Delhi which is the national capital of India is located at 28.61°N 77.23°E, and lies
in Northern India. It borders the Indian states of Haryana on the north, west and south
and Uttar Pradesh (UP) to the east. Two prominent features of the geography of Delhi
are the Yamuna flood plains and the Delhi ridge.
INTACH’s (Indian National Trust for Art and Cultural Heritage) blueprint for water
augmentation mapped all water resources as well as possible groundwater recharge sites
such as paleo-channels and lineaments. It identified 44 lakes and 355 village ponds as
major sites for water storage and recharge locations. A few of these are water bodies
constructed by Delhi rulers in the past that have become defunct with time. When
revived they can be used for storage of rainwater and groundwater that will aid in
recharging the groundwater in the associated aquifers, in addition to providing habitat
for biodiversity.
Hauz Khas Complex houses a water tank, an Islamic seminary, a mosque, a
tomb and pavilions built around an urbanized village with medieval history traced to
the thirteenth century of Delhi Sultanate reign. It was part of Siri, the second medieval
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city of India of the Delhi Sultanate of Allauddin Khilji Dynasty (1296–1316). Hauz Khas
is a historic place and the lake inside it is 700 years old. The latitude is 28.55 deg N and
longitude is 77.19 deg E. The tank is 26 km far from Yamuna River. The area of the lake
is surrounded by Deer Park, Safdarjang Enclave and Green Park.
Hauz Khas as shown below is located is located in South Delhi in Zone –F which is full of
protected monuments, forested areas and heritage sites so, it is called “GREEN LUNG” of
the Delhi city.
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Hauz Khas as per the google earth view resides in the heart of the dense Deer park and
has been a prime tourist spot for many years.
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3.2. Tank Source and Restoration in 2004
The Hauz Khas tank which was originally of about 50 ha (123.6 acres) area with
dimensions of 600 m (1,968.5 ft) width and 700 m (2,296.6 ft) length with 4 m (13.1 ft)
depth of water faced a brief period of being bereft of water (See Figure) due to
evaporation losses and no make-up water source. To make the situation worse, the lake
was located at a place where adjacent land use cannot be changed and no other source
of surface water was available to retrieve the lake. The bed of the Hauz was concretized
with a 50 mm thick layer of lean concrete in 1968 with a view to stop the tremendous
percolation losses. Over a period of time the layer had crumbled and was completely
ineffective. Several trees had taken root in shallow mud pockets in the bed and several
more have been planted along the 1 km. long edge. From the lake management point of
view this vegetation is a nightmare as it multiplies the in situ organic load through decay
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and leaf fall. The littoral zone is also steep with stone-pitched banks and little vegetation.
There is an island of 0.40 ha with steep banks but thick vegetation.
The stratum is extremely porous and makes it difficult to retain surface water. The water
holding capacity of Hauz Khas has now come down to mere 128,000 cum from a
whooping 800,000 cum when built due to decreased depth of the tank mainly because of
siltation and continuous percolation and evaporation losses.
To rectify the situation, INTACH had proposed a scheme to rejuvenate the Hauz Khas
Tank. The following scheme was implemented:-
• One MGD (Million Gallon per Day) treated effluent from Vasant Kunj STP was
utilized for filling the lake after further treatment with duckweeds (Spirodella,
Lemna, Wolffia) in the water retained in existing check dams in the catchment.
Three storm water channels which lie on the upstream side of the Hauz emerge
south of the Hauz from the southern ridge area and serve a catchment of
approximately 10 sq.km. These channels are carrying wastewaters/sewage from
unsewered areas of heavily urbanized catchment, the annual storm water runoff
generated was about 700,000 - 900,000 m3 annually, in a year of average
rainfall.
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• The treated water was conveyed from check dam through a system of pipes (600
mm ø) and chambers. The pipes were laid on the bed of the storm water channel
to ensure that nonpoint pollution does not affect the water quality en route.
• The entire flow was accomplished with gravity.
• Based on the flow regime the average flow was estimated at 2000 m3/d (cubic
meters per day) after accounting for diversions upstream of Sanjay Van, seepage
losses in Sanjay Van, trans-evaporation by the plant community in the aquatic
plants lagoon in Sanjay Van and removals in IIT campus.
• After filling the Hauz to full capacity the losses on account of evaporation and
percolation had to be made up. The percolation losses were assumed as a stable
constant whereas the evaporation losses would vary with the seasons. The
losses were estimated between 940 m3/d in May to 600 m3/d in December –
January.
• After filling the Hauz appropriate fish species were introduced in the reservoir.