1. LAKE RESTORATION
Shilpa Gupta 2008UCE559
Saurabh Goyal 2008UCE426
Sayeed Ahmed Masih 2008UCE905

2. Outline
• Introduction
• Function of lakes
• Degradation of lakes
• Lake Restoration Methods
• Preventive Or Direct Methods
• Ameliorative Or Direct Methods
• Case Study
• Introduction
• Materrials and Methods
• Results and Discussions
• Integrated Restoration Plans

3. Introduction
Lake is a very general term used for any standing
water, generally large enough in area and depth,
but irrespective of its hydrology, ecology, and
other characteristics.
These water bodies are used primarily for
drinking water supplies, irrigation and/or
recreation.
Marginal aquatic vegetation is to be promoted
because it checks erosion and helps improve
water quality.

4. Functions of Lakes
• Lakes are majorly for storage of water.
• Most riverine lakes (oxbows) play a very important role
in flood mitigation and groundwater recharge.
• At the landscape level, large lakes significantly
influence microclimate and therefore influence biotic
diversity.
• Man-made lakes have been constructed mostly to store
seasonally available water, usually for urban water
supply and/or irrigation.
• Power generation is generally a collateral use.
• Groundwater recharge.

5. Degradation of Lakes
• Most lake pollution problems are caused by
nutrients, contaminants, and sediments carried into the
lakes. Soil particles carry more than 90 percent of the
organic nitrogen and phosphorus originating from upland
agricultural practices. Sediments come from all over the
land and thus have nonpoint sources, whereas nutrients
can have both nonpoint and point sources.
• In a typical watershed, nutrients may come from
sewage, wastewater, agricultural and urban runoff, and
atmospheric fallout. In recent years, heavy use of fertilizers
and pesticides and high rates of soil erosion have increased
the severity of the problem.
• High concentrations of nitrogen and phosphorus are the
main causes of algal growth, which results in the
deterioration of the lake water quality.

6. Washing clothes on lake shore Buffaloes wading into the lake
Drain carrying waste to the lakes Trapa cultivation in shallow lake

7. Lake restoration methods
Restoration of lakes for improvement in water
quality requires therefore interventions that
address both the factors responsible for an
increase in nutrient load and the accumulated
nutrients.
The various lake restoration methods can be
considered under two broad categories:
1) preventive or indirect methods, and
2) ameliorative or direct methods.

9. Preventive Or Direct Methods
1. Drainage Basin Alterations: This approach is useful
primarily for controlling nonpoint sources of pollution
which are incidental to the land use of the drainage
basin of the lake.
The drainage basin alterations involve structural and
land treatment measures and interception of
nutrients and sediments before they reach the lake.
The main soil erosion management practices include
terracing, contour farming, grassed waterways,
conservation cropping systems, crop residue
management or increases in the amount of residue
left after harvesting, and creation of shelter belts.

10. Preventive Or Direct Methods
2. Diversion of Wastes: This is a frequently-used solution
for improving the water quality of eutrophic lakes. In
the cases cited, sewage effluents were the main
source of lake eutrophication. Their diversion resulted
in a marked improvement in quality as measured by
increase in transparency, decrease in phytoplankton
biomass, and increase in species diversity.
3. Legal Control Measures: Some political jurisdictions
can impose legal controls on the land use and
discharge of nutrients so as to restrict uses with direct
or indirect pollution potential or effects.

11. Ameliorative Or Direct Methods
• In-Lake Physical Methods
1. Mechanical Harvesting of Biomass
2. Lake Deepening or Dredging
3. Admission of Unpolluted Waters (Dilution/Flushing)
4. Aeration of Water
5. Hypolimnetic Drainage
6. Lake Drawdown
7. Lake Bottom Sealing
• In-Lake Chemical Methods
1. Phosphorus Precipitation
2. Use of Algicides and Herbicides

12. Ameliorative Or Direct Methods
• In-Lake Biological Methods
Species manipulation is the main in-lake biological
method for lake restoration. The method considers the
introduction or promotion of organisms that are
inimical to the target organisms. In nature, predation
by zooplankton and fish species keeps a sort of control
on algal populations. Biological in-lake control
measures are still in their infancy and are not widely
used.
• Out side-Lake Physical Methods
1. Mechanical Treatment
2. Reduction in Sediment Input

13. Ameliorative Or Direct Methods
• Outside-Lake Chemical Methods
1. Clarification
2. Active Carbon Adsorption
3. Ammonia Stripping
4. Nutrient and Ion Removal
5. Disinfection
• Out side-Lake Biological Methods
Primary treatment of sewage is achieved with plain
sedimentation. The fresh solids contain most of the settleable
solids in the raw wastewater. An aerobic digestion destroys
about 67 percent of the volatile matter, and about a quarter of
it is converted to fixed solids. The secondary treatment
includes trickling filters and activated sludge. Advanced waste
treatment methods and processes remove more contaminants
from wastewater than are usually taken out by conventional
secondary treatment plants.

14. Case Study
An Integrated Restoration Plan for Lake
Anasagar: A Threatened
Water Body of Ajmer, Rajasthan, India
SHARMA K C, CHARAN P D and NAG Mudita
Department of Environmental Science, MDS
University, Ajmer-305009, India

15. Introduction
The lake Anasagar is a perennial, shallow fresh waterbody
situated in the heart of Ajmer city. The lake was made
during 1135-1150 AD by the then ruler Anaji Chouhan by
constructing a dam across the river Luni and was named as
Anasagar after his name. Around 35% population of Ajmer
resides in the catchment area of the lake. The climate of
the region is semi-arid with strong seasonality of rainfall.
It is a threatened water body. Once the most beautiful lake
in North-West part of British India is now extremely
polluted because of anthropogenic activities like sewage
disposal, cloth washing and agricultural activities. The lake
area is being encroached for housing which has reduced
water spread. Besides use of chemical fertilizers in the lake
corridor, pesticides are used by farmers for aquaculture and
cultivation of other crops.

16. Material and Methods
Analysis of physico-chemical parameters helps in
assessment of water quality, which is further required for
evolving an appropriate restoration plan. The water
samples were taken from 0.3 m below the surface with
amber colored 1 liter bottle already rinsed with ethyl
acetate and heated at 250°C (4 hours) before use. The
samples were stored at 4°C and were analyzed within a
weeks time. For analysis of HCH residues, mud samples
were collected from the bottom of the lake using Ekmann
Dredge. Standard extraction procedure for sediments was
followed for HCH residue analysis. The factors degrading
the water quality were identified during extensive surveys
to develop a restoration plan considering various ecological
and socioeconomic constrains.

17. Results and Discussion
Results of analyses carried out for 240
samples in 2007 and 2008 from five different
sites demonstrate that the lake is eutrophic
and severely polluted.
The factors of degradation were identified as:
• Agrochemicals and pesticides
• Sedimentation and Soil Erosion
• Socio-economic Aspects
• Acquisition of land

19. Integrated Restoration Plan
As a strategy, the lake restoration programme must involve
activities to protect, restore, manipulate, and provide for
the functions and values emphasizing quality and
sustainable usage of water resource.
1. Catchment Development Plan:
Developing a tree belt in the barren area of catchment,
check the soil erosion. Sand dunes in the catchment area
are stabilized by revegetation. Desilting of the lake in the
initial phase may be taken as a major activity for
restoration. The sediment of Lake Anasagar is rich in
nutrients (N and P) which may be utilized as fertilizers in
agricultural fields. The practice should be repeated
periodically till the lake resumes its ecological integrity.

20. Integrated Restoration Plan
2. Lake Area Development
A layout plan for Lake Anasagar was
designed in view of both
recreational activities and
maintaining ecological integrity for
long term restoration and
sustainability. The peripheral area is
restored through proposed
ecoarchitectural plan. This includes
periodic removal of sediments and
organic debris from littoral zone.
This sediment is rich in P and N
nutrients and may be used as
fertilizer for agricultural fields.

22. References
• Ministry of Environment and Forests. 2008. Guidelines for National Lake Conservation Plan.
National River Conservation Directorate, Ministry of Environment and Forests. Government of
India, New Delhi. 14 pp.
• Krishan P. Singh, Ph.D., Principal Scientist. LAKE RESTORATION METHODS AND FEASIBILITY OF
WATER QUALITY MANAGEMENT IN LAKE OF THE WOODS, State Water Survey Division SURFACE
WATER SECTION AT THE UNIVERSITY OF ILLINOIS
• Hyderabad Urban Development Authority. 2005. National Seminar on Management of Urban Lakes,
1-2 Dec 2005. Proceedings. 28 pp.
• Gopal, B., A. Chatterjee & P. Gautam. 2007. Sacred Waters of the Himalaya. WWF-India, New Delhi.
• Kodarkar, M.S. & Sandeep Joshi. 2006. Conservation and management of lakes in urban
environment; bioremediation a new frontier in the control of eutrophication in urban lakes.
Proceedings Vol. II, 11th World Lake Conference, Nairobi, Kenya. Pp. 79 – 82.
• Lake Conservation Authority. 2008. The Lake Atlas of Madhya Pradesh. Bhopal.
• Ministry of Environment and Forests. 2009. National Wetland Conservation Programme: Guidelines
for Conservation and Management of Wetlands in India (Revised on 12.06.2009). Conservation and
Survey Division, Ministry of Environment and Forests. Government of India, New Delhi.
• Prabhu Dan Charan, Renu Sharma and K. C. Sharma. ‘Gas ChromatographicAnalysis of
Organochlorine Pesticides In Lake Anasagar of Ajmer, Rajasthan . in Journal of Environmental
Science & Engineering. 90/8/2009 (In press).
• Charan, P.D. and Sharma, K.C. Analysisof residual pesticides in surface and ground water samples of
central Aravalli region of Rajasthan.International Journal of Bioscience Reporter, 2009.7(1): 15-20.
• Singh, S., Dureja, P., Kumar, S. and Jain, M.C. Persistance of α and β isomers of endosulfan and
Endosulfan sulphate in diverse soils of India as influenced by flooding. Journal of Environment and
Health. 1999. B-34:965-974.

23. Thank You!