solution finder

solution finder

Lakes

Author/Compiled by
Beat Stauffer (seecon international gmbh)
Dorothee Spuhler (seecon international gmbh)
Executive Summary

Lakes are surface water sources, with water levels changing depending on the seasons. Lakes usually play an important role in the supply of water for the regional population (household use), industry and agriculture. Lake management has to consider that the amount of water extracted is not higher than water entering the lake; pollution and eutrophication; as well as sedimentation to guarantee an ecological balance and a constant quality of water for use. There are natural lakes and man-made lakes, also called reservoirs.

Advantages
Quickly and easily accessible water source
Fresh and clean water needs only little further treatment
A lake is an important economic factor for a region (drinking water, tourism, etc.)
Can be used to produce energy
Disadvantages
Riparian conflicts can occur especially in arid areas
Often misused to discharge waste water and solid waste
Expensive intake constructions for large scale extraction necessary
In Out

Precipitation, Freshwater, Drinking Water, Treated Water

Freshwater, Drinking Water

Introduction

Lakes, like every surface water source, are very important for water supply in communities, cities, agriculture and industry. Lakes exist as two types of surface water sources: as natural lakes, and as artificial lakes (also called reservoirs). Normally, lakes are fed and drained by rivers or streams, but are also supplied by precipitation run-off (see also the water cycle). Even though surface water and ground water are usually evaluated as separate water masses, they interact depending on physiographic and climatic setting of the landscape (U.S. EPA 2000). Physical impairments to water quality include a variety of parameters, such as temperature, turbidity and pH (acidity) and they describe the general condition of the water and its ability to support aquatic life. The following table lists the most common physical water quality parameters measured and compares the characteristics of surface water and groundwater based on these parameters (EC 2010).

Characteristic

Surface Water

Ground Water

Temperature

Varies with season

Relatively constant

Turbidity, Suspended Solids (SS)

Level variable, sometimes high

Low or nil (except in karst soil)

Colour

Due mainly to SS (clays, algae) except in very soft or acidic waters (humic acids)

Due above all to dissolved solids

Mineral content

Varies with soil, rainfall, effluents, etc.

Largely constant, generally appreciably higher than in surface water from the same area

Divalent Fe and Mn in solution

Usually none, except at the bottom of lakes and ponds in the process of eutrophication

Usually present

Aggressive CO2

Usually none

Often present

Dissolved O2

Often near saturation level, absent in very polluted water

Usually none

Hydrogen Sulfide H2S

Usually none

Often present

Ammonium NH4

Found only in polluted water

Often found

Nitrates

Level generally low

Level sometimes high

Silica

Usually moderate proportions

Level often high

Mineral and organic micro-pollutants

Can be present but liable to disappear rapidly once the source is removed

Usually none but any accidental pollution lasts a very long time

Living organisms

Bacteria, viruses, plankton

Iron bacteria frequently found

Chlorinated solvents

Rarely present

Often present

Eutrophic nature

Often. Increased by high temperatures

None

Table 1: Physical characteristics of surface water and groundwater. Source: LENNTECH (2012)

Pollution and Disturbances

 High pollution in Guadalupe Lake, Mexico. Source: UAF (2010)

High pollution in Guadalupe Lake, Mexico. Source: UAF (2010) 

When humans disturb the natural, protective vegetative cover of the landscape with settlements, roads, farms, etc., the types and amounts of materials dissolved or carried into the lakes by runoff change significantly (WATERENCYCLOPEDIA 2011). Nonpoint-source pollution is another term for polluted runoff (see also water pollution). Run-off is the water washing over the land, whether from precipitation, car washing or watering crops or lawns, etc., picks up an array of contaminants including oil, sand and salt from roadways, agricultural chemicals, and nutrients and toxic materials from both urban and rural areas. The term nonpoint is used to distinguish this type of pollution from point source pollution, which comes from specific sources such as sewage treatment plants or industrial facilities. The major types of pollutants are listed below (adapted from COASTAL CENTRE 2012):

  • Nutrients are compounds that stimulate plant growth, like nitrogen and phosphorous. In high concentrations, they can become both an environmental and health threat. Nutrients in polluted waters can come from agricultural fertilisers, septic systems, home lawn care products, and yard and animal wastes.
  • Pathogens are disease-causing microorganisms, such as bacteria and viruses that come from the faecal waste of animals and humans. Pathogens wash off the land from wild animal, farm animal and pet waste, and can also enter the lake from improperly functioning septic systems, leaky sewer lines and boat sanitary disposal systems.
  • Toxins are substances that can harm aquatic and human life. They are created by a wide variety of human practices and products like heavy metals, pesticides and organic compounds like PCB’s. Many toxins are resistant to breakdown and tend to be passed through the food chain to be concentrated in top predators. Oil, grease and gasoline from roadways, and chemicals used in home, gardens, yards and on farm crops, are major sources of toxic contaminants.

Eutrophication

 Cultural eutrophication model. Source: SYLLABUS (2012)

Cultural eutrophication model. Source: SYLLABUS (2012) 

Excessive fertilisation (eutrophication) of lakes and reservoirs is recognised as one of the most important causes of water quality impairment of lakes, reservoirs, some streams, rivers, and near-shore marine waters (JONES LEE and LEE n.y.); see also water pollution. Eutrophication of lakes is best defined as the excessive addition of inorganic nutrients, organic matter, and silt that causes a corresponding increase in biological productivity. High concentrations of nutrients alone do not make a lake eutrophic; there must be a biological response as well. Nutrient concentrations, however, may be used as indicators for the potential of eutrophication. For example, phosphorus concentrations exceeding 30 micrograms per litre are sufficient to cause excessive algal growth in some lakes, and therefore eutrophication (WATERENCYCLOPEDIA 2011). Possible solutions to avoid eutrophication are waste water treatment at the source, retention ponds to stop nutrients before entering the surface water source or buffer zones between agricultural land and open water sources. In the United States for instance, industrial agriculture is one of the leading causes of water pollution. Read more about it in the article by SUSTAINABLE TABLE (n.y.)

How to Avoid Pollution

To avoid pollution, wastewater should be treated before discharged into surface water. Read more about the different options here. To avoid pollution from residential surface runoff, proper stormwater management should be implemented.

Extraction and Distribution

 Schematic sketch of variable depth lake water intake (top). For small capacity intakes, simple arrangements using flexible plastic pipes can be used (bottom). Source: SMET and WIJK (2002)

Schematic sketch of variable depth lake water intake (top). For small capacity intakes, simple arrangements using flexible plastic pipes can be used (bottom). Source: SMET and WIJK (2002). 

Water for household use can be extracted and distributed by buckets or pumped into water trucks to transport larger amounts of water. Before it is used it should be purified. Water can also be pumped into a distribution network. To extract large amounts of water for cities (drinking water), agriculture (irrigation) or industrial use (e.g cooling water or commercial fishing, hydropower), permanent water intakes are necessary. Another important technique to extract drinking water is called bank filtration. Surface water from river systems or lakes infiltrates through the soil, with acts as a purification filter, into the groundwater where it can be extracted.

The city of Zurich extracts 70% of its drinking water from Lake Zurich. There are two intakes in the lake at a depth of 30 metres (and approx. 500 m away from the shore) where the water has a constant temperature (6 to 8 °C) and does not interfere with commercial shipping. From there it is pumped to sedimentation pools and purified (sand filter, active carbon filter and ozone) before it is introduced into the drinking water network of the city (STADT ZUERICH 2012).

It does not matter if water is extracted from a water source for drinking or for irrigation, but the amount of water used must be less than the amount that is available in the source. To estimate the availability and to strengthen water management decision-making also see the factsheet water balance estimation.

Possible Conflicts

 The Great Lakes (here Lake Superior) are a vast shared resource containing a significant portion of the world's freshwater. They are fundamental to the well-being of many Canadians and Americans, as well as sustaining a rich variety of plants and animals. The Great Lakes provide the foundation for billions of dollars in economic activity, and they are a direct source of drinking water for millions of Americans and Canadians. Source: EC (2011) and B. STAUFFER (2004)

The Great Lakes (here Lake Superior) are a vast shared resource containing a significant portion of the world's freshwater. They are fundamental to the well-being of many Canadians and Americans, as well as sustaining a rich variety of plants and animals. The Great Lakes provide the foundation for billions of dollars in economic activity, and they are a direct source of drinking water for millions of Americans and Canadians. Source: EC (2011) and B. STAUFFER (2004) 

A lake, especially in densely populated areas and arid regions, serves many uses (see also water use) and the potential for conflicts is high. Some of them are listed below:

  • Drinking water source: Lakes are very big drinking water sources (e.g. Lake of Constance for Switzerland, Austria and Germany, or The Great Lakes in North America), making them significant economical factors for a region. The potential for conflicts is even higher in arid regions.
  • Agriculture: Lakes (as well as reservoirs) are important water sources for irrigation.
  • Energy production: A lake could be used as a reservoir for hydropower production (small- or large-scale).
  • Tourism and recreation: In many cases, this is an important economic factor for the region (HAMMERL and GATTENHOENER n.y.). Tourists travel to a lake area for vacation (also day trips), sports or fishing.
  • Wildlife and habitants: A lake and its wetlands are a natural ecosystem and habitat for many animals and plants (HAMMERL and GATTENHOENER n.y.).
  • Shoreline constructions: In addition to the settlements and the transportation infrastructure, there are also recreational facilities, shoreline fortifications and excavations for sand and gravel (HAMMERL and GATTENHOENER n.y.).
  • Fisheries: In many countries, people are dependent on a lake’s fishing grounds. Therefore, water quality should be adequate and (natural) spawning ground existent.

Health Aspects

No potentially hazardous substances should be channelled into lakes, because the ecosystem services could be negatively influenced through water pollution which can cause waterborne diseases (see also water source and well protection). Wastewater treatment and semicentralised drinking water treatments are important before further use (e.g. free surface, horizontal or vertical constructed wetlands).

The quality of lake water is influenced by self-purification through aeration, bio-chemical processes, and settling of suspended solids. The water can be very clear, of low organic content and with high oxygen saturation. Usually, human and animal pollution only presents a health hazard near the shore. At some distance from the shore, the lake water generally has a low density of pathogenic bacteria and viruses. However, algae may be present, particularly in the upper layers of lakes (SMET and WIJK 2002).

 

Applicability

A lake is a very important water source for its region. The stored water can be used as drinking water after proper treatment or for irrigation. Furthermore, a lake is an important economical factor. Tourism, shipping, fisheries are some of the industrial sectors that benefit from a lake. Proper lake management is very important to avoid conflicts and pollution

Library references

Lake Constance

HAMMERL ; GATTENHOENER ; (n.y): Experience and Lessons Learned Brief URL [Accessed: 04.06.2012]

Eutrophication (Excessive Fertilization)

“Eutrophication” has become synonymous with “excessive fertilisation” or the input of sufficient amounts of aquatic plant nutrients to cause the growth of excessive amounts of algae and/or aquatic macrophytes in a water body such that beneficial uses of the water body (i.e., water quality) are impaired. Beneficial uses of water bodies that stand to be impaired by the presence of excessive amounts of aquatic plant life include domestic and industrial water supply, recreation, and fisheries. Because of the public health and environmental quality significance of these water quality impairments, myriad strategies have been advanced to evaluate and regulate excessive fertilisation.

JONES LEE, A. ; LEE, G.F. ; (n.y): El Macero: G. Fred Lee & Associates URL [Accessed: 24.01.2012]

Small Community Water Supplies: Technology, People and Partnership: Surface Water - Chapter 11

This book provides a general introduction to a wide range of technologies. Among the topics covered are: planning and management of small water supplies, community water supplies in Central and Eastern European countries, water quality and quantity, integrated water resources management, artificial recharge, rainwater harvesting, spring water tapping, groundwater withdrawal, water lifting, surface water intake, water treatment, aeration, coagulation and flocculation, sedimentation, multi-stage filtration, desalination technology, disinfection, household level water treatment, technologies for arsenic and iron removal from ground water, and emergency and disaster water supply. Chapter 11: Surface Water

SMET, J. ; WIJK, C. van (2002): The Hague: International Water and Sanitation Centre (IRC) URL [Accessed: 29.02.2012]

Industrial Agriculture Water Pollution

Industrial agriculture is one of the leading causes of water pollution in the United States today. In the 2000 National Water Quality Inventory conducted by the Environmental Protection Agency (EPA), agricultural activity was identified as a source of pollution for 48% of stream and river water, and for 41% of lake water. Read more about it in this article.

SUSTAINABLE TABLE (n.y): New York: Sustainable Table URL [Accessed: 12.03.2012]
Further Readings

Sick Water? The central role of wastewater management in sustainable development

This book not only identifies the threats to human and ecological health that water pollution has and highlights the consequences of inaction, but also presents opportunities, where appropriate policy and management responses over the short and longer term can trigger employment, support livelihoods, boost public and ecosystem health and contribute to more intelligent water management.

CORCORAN, E. ; NELLEMANN, C. ; BAKER, E. ; BOS, R. ; OSBORN, D. ; SAVELLI, H. (2010): A Rapid Response Assessment. United Nations Environment Programme (UNEP), UN-HABITAT, GRID-Arendal URL [Accessed: 05.05.2010]

Control of Water Pollution from Agriculture

Environmental pollution is a major global concern. When sources of water pollution are enumerated, agriculture is, with increasing frequency, listed as a major contributor. As nations make efforts to correct abuses to their water resources, there is a need to determine the causes of water quality degradation and to quantify pollution contributions from many sources. Until such time as adequate facts are made available through research to delineate causes and sources, conflicting opinions continue to flourish and programmes to control and abate pollution will be less effective and efficient in the use of limited resources.

FAO (1996): Rome: FAO: Food and Agriculture Organization of the United Nations (FAO) URL [Accessed: 12.03.2012]

Lake Ecosystems

Lakes are discrete, largely isolated ecosystems in which the interplay between physical, biogeochemical and organismal processes can be studied, understood, and put to use in effective management. Read more about it in this article.

HAIRSTON, N.G. ; FUSSMANN, G.F. ; (2002): New York: Macmillan Publishers Ltd URL [Accessed: 14.12.2011]

Understanding Lake Ecology

Limnology is the study of fresh or saline waters contained within continental boundaries. Limnology and the closely related science of oceanography together cover all aquatic ecosystems. Although many limnologists are freshwater ecologists, physical, chemical, and engineering limnologists all participate in this branch of science. Limnology covers lakes, ponds, reservoirs, streams, rivers, wetlands, and estuaries, while oceanography covers the open sea. Limnology evolved into a distinct science only in the past two centuries, when improvements in microscopes, the invention of the silk plankton net, and improvements in the thermometer combined to show that lakes are complex ecological systems with distinct structures. This document gives you a broad overview.

HORNE, A.J. ; GOLDMAN, C.R. ; (1994): New York: McGraw-Hill Co URL [Accessed: 14.12.2011]

Eutrophication (Excessive Fertilization)

“Eutrophication” has become synonymous with “excessive fertilisation” or the input of sufficient amounts of aquatic plant nutrients to cause the growth of excessive amounts of algae and/or aquatic macrophytes in a water body such that beneficial uses of the water body (i.e., water quality) are impaired. Beneficial uses of water bodies that stand to be impaired by the presence of excessive amounts of aquatic plant life include domestic and industrial water supply, recreation, and fisheries. Because of the public health and environmental quality significance of these water quality impairments, myriad strategies have been advanced to evaluate and regulate excessive fertilisation.

JONES LEE, A. ; LEE, G.F. ; (n.y): El Macero: G. Fred Lee & Associates URL [Accessed: 24.01.2012]

Small Community Water Supplies: Technology, People and Partnership: Surface Water - Chapter 11

This book provides a general introduction to a wide range of technologies. Among the topics covered are: planning and management of small water supplies, community water supplies in Central and Eastern European countries, water quality and quantity, integrated water resources management, artificial recharge, rainwater harvesting, spring water tapping, groundwater withdrawal, water lifting, surface water intake, water treatment, aeration, coagulation and flocculation, sedimentation, multi-stage filtration, desalination technology, disinfection, household level water treatment, technologies for arsenic and iron removal from ground water, and emergency and disaster water supply. Chapter 11: Surface Water

SMET, J. ; WIJK, C. van (2002): The Hague: International Water and Sanitation Centre (IRC) URL [Accessed: 29.02.2012]

Interaction of Ground Water and Surface Water in Different Landscapes

The interaction of ground water with surface water depends on the physiographic and climatic setting of the landscape. The five general types of terrain discussed are mountainous, riverine, coastal, glacial and dune, and karst.

USGS (2001): Washington D.C.: U.S. Geological Survey; U.S. Department of the Interior URL [Accessed: 09.10.2012]

Chemical Safety of Drinking Water Assessing Priorities for Risk Management

Identifying and prioritizing chemical risks presents a challenge, especially in developing countries, because information on the presence of chemicals in water supplies is often lacking. This document provides guidance to help readers to meet that challenge. It shows how information on aspects such as geology and industrial and agricultural development, which is often readily available, can be used to identify potential chemical contaminants (and potential sources of chemicals), from catchment to consumer, and thus prioritize risks. This is a supporting document to the Guidelines for Drinking-water Quality (WHO 2008 and WHO 2011), and it is aimed at policy-makers, regulators, managers and public health practitioners at national and local level.

WHO (2007): Geneva: World Health Organization (WHO) URL [Accessed: 12.10.2011]

Lakes, Electricity & You

Back in the mid-1940s, Congress recognised the need for better flood control and navigation. To pay for these services, Congress passed laws that started the building of federal hydroelectric dams, and sold the power from the dams under long-term contracts. Today these dams provide efficient, environmentally safe electricity for cities and rural areas.

SEPA (n.y): Elberton: Southeastern Power Administration (SEPA) URL [Accessed: 12.03.2012]

Industrial Agriculture Water Pollution

Industrial agriculture is one of the leading causes of water pollution in the United States today. In the 2000 National Water Quality Inventory conducted by the Environmental Protection Agency (EPA), agricultural activity was identified as a source of pollution for 48% of stream and river water, and for 41% of lake water. Read more about it in this article.

SUSTAINABLE TABLE (n.y): New York: Sustainable Table URL [Accessed: 12.03.2012]
Case Studies

Prescription for Great Lakes Ecosystem Protection and Restoration

There is widespread agreement that the Great Lakes presently are exhibiting symptoms of extreme stress. Many sources of pollution have been impacting the lakes for over a century. The conceptual model here indicates the importance of immediate and sustained action. It advocates using the principles of ecosystem-based management to restore and protect the Great Lakes. Without such action, the lakes could potentially suffer irreversible and catastrophic damage.

BAILS, J. ; BEETON, A. ; BULKLEY, J. ; DEPHILIP, M. ; GANNON, J. ; MURRAY, M. ; REGIER, H. ; SCAVIA, D. ; (2005): Ann Arbor: Great Lakes Information Network URL [Accessed: 14.12.2011]

Case Study of the Aral Sea Water and Environmental Management Project

This review discusses the dire conditions of the Aral Sea, which has seen its surface area decline by two-thirds since 1960. The Aral Sea Water and Environmental Management Project was designed to help the countries in the area solve the environmental crises.

BARGHOUTI, S. ; (2006): Geneva: World Health Organisation (WHO) URL [Accessed: 13.12.2011]

Temperature Effects on Bank Filtration: Redox Conditions and Physical-chemical Parameters of Pore Water at Lake Tegel, Berlin, Germany

This research paper from Lake Tegel in Berlin, Germany, describes how water warming through climate change can lead to large-scale changes in natural self-purification capacities during bank filtration, such as decrease in redox potential and the development of anoxic conditions. Rather suited for people with biochemical knowledge.

GROSS-WITTKE, A. ; GUNKEL, G. ; HOFFMANN, A. ; (2010): London: IWA Publishing URL [Accessed: 29.08.2011]
Training Material

Water Sources

This pdf-presentation contains information on and pictures of rainwater harvesting, spring water tapping, surface water intake and ground water withdrawal.

WAFLER, M. (2010): Wien: seecon international gmbh

Alternative Versions to

No Structure Described.