**1. Introduction**

Clean freshwater is the most precious resource in the world and the development of water resources has had a very long history, as early as humans changed from being hunters and food collectors to modern civilization. At very early stage, people had to rely on creeks, rivers and lakes for their water demand that was relatively small, and today humans have accumulated the knowledge and techniques for water storage, building artificial lakes or reservoirs to meet their huge water demand due to industrialization and urbanization. The world's earliest large dam was the Sadd-el-kafara Dam built in Egypt between 2950 and 2690 B.C. Up to now, water from lakes and reservoirs is still the main source for people's water supply. However these large water bodies suffer two problems incurred by nature and human being, one is *sedimentation* and the other *water pollution*. Two of them jointly reduce the available amount of clean water and deteriorate the water quality. Consequently, approximate 1.1 billion people lack of safe drinking water and between 2 and 5 million people die annually from water-related disease (Gleick, 2004). It is understandable that with the population growth in the world, it is difficult to provide sufficient clean water to meet the demand; on the other hand, our natural systems are under pressure from drought (too little), floods (too much), pollution (too dirty), climate change, and other stresses. This creates serious challenges for water management.

Within a generation, water demand in many countries is forecast to exceed supply by an estimated 40%. In other parts of the world prone to flooding, catastrophic floods normally expected once a century could occur every 20 years instead.

Currently, there are about 40,000 large reservoirs worldwide used for water supply, power generation, flood control, etc. The total sediment yield in the world is estimated to be 13.5×109 tonnes/a or 150tonnes/km2 and about 25% of this is transported into the seas and oceans and the rest 75% is trapped, retained and stored in the lakes, reservoirs and river systems (Batuca and Jordaan, 2000). Consequently the silting process is reducing the storage capacity of the world's reservoirs by more than 1% per year. As a result of sedimentation,

Novel SPP Water Management Strategy and Its Applications 241

Until 1800s, most materials used in homes and industries were natural products. In 1900s petroleum was used widely, in 1940s explosion in chemical production and in 1930s to 1950s chemicals like fertilizers and pesticides were invented and found very effective. On the other hand, the urbanization and modern agriculture have changed people's living habit and have greatly enhanced the food productivity. Consequently, domestic/agricultural waste water has also increased significantly with the same trend as industrial wastewater. The United Nation and World Bank's statistics shows that the world discharges 400 billion tons of wastewater every year, resulting in that 5,000 billion ton of clean water being polluted. Among them, China releases 60 billion ton of wastewater every year into rivers and lakes, greatly damaging its ecosystem. As a result of the rapid growth in industrial development, urbanization and population, the world's water resources are grossly polluted by human, agricultural and industrial wastes, to the point that vast stretches of rivers are

Substances in water

Drops, bubbles Suspended

sediment

Bed materials sediment

Dissolved substances Emulsified substance Particles

The world's current strategies in relation to water management are mainly focused on construction of reservoirs, wastewater reuse, desalination technology, alongside nonengineering methods like marketplace allocation etc. Increasingly, water planners have to take into account societal responses to proposed technologies as illustrated by the opposition to new dams, not to mention the hostile public reception met by wastewater and desalination strategies. Thus, it is worthwhile investigating other alternative water management strategy as long as it proves to be cost effective, energy thrifty and environment-friendly. By far, reservoirs and lakes play an important role for the modern society. As mentioned above, the biggest challenge is that the incoming rivers to these large water bodies are severely polluted by contaminants particle or solvable pollutants in water. The almost stagnant water together with high temperature, suitable sun shine and nutrients often leads to the algal blooms on vast scales that have become a major water quality issue for ecosystems throughout the world. It is an urgent threat facing surface water resources today, because of their ecological, aesthetic, and human health impacts. Blooms involving toxin-producing species pose serious threats to animals, plants and humans. Bloom occurrence is visible evidence that humans now strongly effect almost every aspect of our

Humic acids (0.01-0.1 mm), Post filters particles (0.4-10 mm), Flocculated particles (1-100 mm).

Hydro-dynamically neutral

dead and dying and lakes are cesspools of waste.

Hydro-dynamically Active (change in viscosity and density

Fig. 1. Classification of substances in water

300-400 new dams would need to be constructed annually to maintain current total storage (White, 2001). On the other hand, due to climate change, the natural erosion rates will be accelerated. UN experts warned that a fifth of the current storage capacity of reservoirs worldwide or 1,500 km3 will be gradually lost over the coming decades as global warming may increase the severity of storms and rains. Thus, one may conclude that the worst enemy of sustainable water resources management is sedimentation (USBR, 2006).

In 1998 the U.S. Environmental Protection Agency has identified that sediment in waterways is the largest single pollutant in the ecosystem (National Water Quality Inventory Section 305(b) Report to Congress), because sediment transported downstream can fill reservoirs, reduce its capacity and impair aquatic habitats. Detrimental effects to fish and aquatic invertebrate have been directly related to increases in the magnitude and duration of suspended sediment concentrations (Newcombe and Jensen, 1996 and Kuhnle et al., 2001). It is found that eutrophication can result from a high sediment load that has elevated levels of colloidal material, phosphorus and nitrogen that are transported in association with the sediment (Davis and Koop, 2006).

Water pollution, the main threat of water quality, began with the industry revolution, and the word "pollution" is an adaptation of the Latin "pollutionem", meaning defilement from "polluere". To many people, water pollution means the introduction into natural water of foreign substance, but strictly speaking, the water pollution refers to the introduction into water of any substances that makes water hazardous to public health. The impurities or foreign substances could be organic, inorganic, radiological or biological, and its presence in water tends to degrade water's quality or impair the usefulness of the water. The substances in water can be classified into three groups as shown in Fig. 1, i.e., dissolved; suspended and colloidal.

A dissolved substance is one which is truly dispersed in the liquid, and cannot be removed from the liquid without accomplishing a phase change such as: distillation, precipitation, adsorption, extraction or passage through ionic pore sized membranes. Suspended solids are large enough to settle out of solution or be removed by filtration. The lower size range of this class is 0.1 to 1 mm that is about the size of bacteria. The suspended solids can be removed from water by physical methods such as: sedimentation, filtration and centrifugation. Colloidal particles are in the size between dissolved substances and suspended particles. They can be removed from the liquid by physical means such as very high forced centrifugation or filtration through membranes with very small pore spaces. When light passes through a liquid containing colloidal particles, the light is reflected, which is measured by turbidity.

The typical impurities in water can be further divided based on its density (equal to or larger or less than the density of water) or size:

Algae (0.3-100 mm), Bacteria (0.1-100 mm), Viruses (0.003-0.3 mm), Fungi (1-90 mm), Giardia cysts (5-16 mm), Colloids (0.01-7 mm), Suspended solids (0.3-100 mm),

300-400 new dams would need to be constructed annually to maintain current total storage (White, 2001). On the other hand, due to climate change, the natural erosion rates will be accelerated. UN experts warned that a fifth of the current storage capacity of reservoirs worldwide or 1,500 km3 will be gradually lost over the coming decades as global warming may increase the severity of storms and rains. Thus, one may conclude that the worst enemy

In 1998 the U.S. Environmental Protection Agency has identified that sediment in waterways is the largest single pollutant in the ecosystem (National Water Quality Inventory Section 305(b) Report to Congress), because sediment transported downstream can fill reservoirs, reduce its capacity and impair aquatic habitats. Detrimental effects to fish and aquatic invertebrate have been directly related to increases in the magnitude and duration of suspended sediment concentrations (Newcombe and Jensen, 1996 and Kuhnle et al., 2001). It is found that eutrophication can result from a high sediment load that has elevated levels of colloidal material, phosphorus and nitrogen that are transported in

Water pollution, the main threat of water quality, began with the industry revolution, and the word "pollution" is an adaptation of the Latin "pollutionem", meaning defilement from "polluere". To many people, water pollution means the introduction into natural water of foreign substance, but strictly speaking, the water pollution refers to the introduction into water of any substances that makes water hazardous to public health. The impurities or foreign substances could be organic, inorganic, radiological or biological, and its presence in water tends to degrade water's quality or impair the usefulness of the water. The substances in water can be classified into three groups as shown in Fig. 1, i.e., dissolved; suspended and

A dissolved substance is one which is truly dispersed in the liquid, and cannot be removed from the liquid without accomplishing a phase change such as: distillation, precipitation, adsorption, extraction or passage through ionic pore sized membranes. Suspended solids are large enough to settle out of solution or be removed by filtration. The lower size range of this class is 0.1 to 1 mm that is about the size of bacteria. The suspended solids can be removed from water by physical methods such as: sedimentation, filtration and centrifugation. Colloidal particles are in the size between dissolved substances and suspended particles. They can be removed from the liquid by physical means such as very high forced centrifugation or filtration through membranes with very small pore spaces. When light passes through a liquid containing colloidal particles, the light is reflected,

The typical impurities in water can be further divided based on its density (equal to or

of sustainable water resources management is sedimentation (USBR, 2006).

association with the sediment (Davis and Koop, 2006).

colloidal.

which is measured by turbidity.

Suspended solids (0.3-100 mm),

Algae (0.3-100 mm), Bacteria (0.1-100 mm), Viruses (0.003-0.3 mm), Fungi (1-90 mm), Giardia cysts (5-16 mm), Colloids (0.01-7 mm),

larger or less than the density of water) or size:

Until 1800s, most materials used in homes and industries were natural products. In 1900s petroleum was used widely, in 1940s explosion in chemical production and in 1930s to 1950s chemicals like fertilizers and pesticides were invented and found very effective. On the other hand, the urbanization and modern agriculture have changed people's living habit and have greatly enhanced the food productivity. Consequently, domestic/agricultural waste water has also increased significantly with the same trend as industrial wastewater. The United Nation and World Bank's statistics shows that the world discharges 400 billion tons of wastewater every year, resulting in that 5,000 billion ton of clean water being polluted. Among them, China releases 60 billion ton of wastewater every year into rivers and lakes, greatly damaging its ecosystem. As a result of the rapid growth in industrial development, urbanization and population, the world's water resources are grossly polluted by human, agricultural and industrial wastes, to the point that vast stretches of rivers are dead and dying and lakes are cesspools of waste.

Fig. 1. Classification of substances in water

The world's current strategies in relation to water management are mainly focused on construction of reservoirs, wastewater reuse, desalination technology, alongside nonengineering methods like marketplace allocation etc. Increasingly, water planners have to take into account societal responses to proposed technologies as illustrated by the opposition to new dams, not to mention the hostile public reception met by wastewater and desalination strategies. Thus, it is worthwhile investigating other alternative water management strategy as long as it proves to be cost effective, energy thrifty and environment-friendly. By far, reservoirs and lakes play an important role for the modern society. As mentioned above, the biggest challenge is that the incoming rivers to these large water bodies are severely polluted by contaminants particle or solvable pollutants in water. The almost stagnant water together with high temperature, suitable sun shine and nutrients often leads to the algal blooms on vast scales that have become a major water quality issue for ecosystems throughout the world. It is an urgent threat facing surface water resources today, because of their ecological, aesthetic, and human health impacts. Blooms involving toxin-producing species pose serious threats to animals, plants and humans. Bloom occurrence is visible evidence that humans now strongly effect almost every aspect of our

Novel SPP Water Management Strategy and Its Applications 243

3. Currently, throughout the world it is rare to find an integrated water resources management plan that can reduce the external nutrients, and at the same time mitigate flood disaster and solve the water shortage problems, i.e., simultaneously solve four problems of flooding (too much), droughts (too little), algal blooms (too dirty) and

Based on these realizations, Yang and Liu (2010) proposed the following SPP strategy to

• Clean water should be stored and *protected* and wastewater should be discharged as fast as possible, i.e., the detention time of wastewater in the lake should be as short as

The objectives of this chapter will be 1) to show how to manage the water and the particles it carries simultaneously, thus the floodwater is regulated for the use in drought seasons, and the lakes/reservoirs' storage capacity is protected with the damaged ecosystem being restored; 2) to compare the new strategy of water management with existing strategies, and the case studies will demonstrate whenever the SPP strategy is applied, the water related

Normally, a natural or artificial lake may comprise multiple incoming and outgoing rivers that collect the rainwater/wastewater from upstream of the lake and drain the lake water to downstream, respectively. The SPP strategy is achievable if an internal levee with sluice gates is built in the lake. By doing so, flood disasters (too much water) of the watershed will be significantly reduced, water shortage problem (too little water) can be alleviated simultaneously, the siltation rate is reduced (too turbid) and clean water resources are protected against pollution. These two levees around the lake shoreline together would form an artificial canal or by-pass channel (BPC) as shown in Fig. 3. The inner bank of the

possible, whilst the residence time of clean water should be as long as possible. • One of the effective ways to *prevent* water deterioration is to maintain water movement since moving water has the self cleaning capacity (self-degradation, self-decomposition and self-purification), and high turbulence shears dispersed planktonic flocs and limits

siltation (too turbid) for a given basin where reservoirs/lakes are located.

• Clean water and wastewater should be *separated* spatially and temporally;

season, very low in dry seasons.

manage different waters in a lake/reservoir:

sessile microbial growth.

disasters can be mitigated, vice versa.

**2. SPP strategy** 

groundwater without being polluted, Qw is the domestic and industrial wastewater discharge, Qs is the sediment discharge, Qa is the rate of wastewater from agriculture or the non-point source pollutant. The year-round rainwater is unsteady, and floods often appears in wet seasons, but wastewater rate from industry and domestic sources is relatively constant year-round even their concentrations in the rivers are not even after mixing. Inflow-river waters are heavily polluted in the dry period while pollutant concentrations are reduced during the wet (flood) period after mixing of clean rainwater with the domestic and industrial wastewater. But this does not mean that the wastewater concentration in flood period is always low as the first flush of storm often drives the non-point source pollutants to the waterways, thus the peak of Qa appears before the peak of Qr. Different from the agricultural wastewater, sediment discharge concentration is roughly proportional to the river flow, i.e., very high during wet

ecosystem. Just like the carbon dioxide emission and climate change, human activities have dramatically increased the emission of nutrients, contributing to increase in phytoplankton biomass and even algal blooms formation in receiving water bodies, e.g. rivers, lakes, coastal waters and reservoirs. With rapid economic/development and population growth worldwide, harmful algal blooms have become more frequent, more extensive, and more severe (Hallegraeff, 1993, Heisler, et al. 2008).

Algal blooms typically appear in slow moving water bodies with excess nutrients e.g. phosphorus, and nitrogen etc., when sunlight, turbulence, transparency, salinity and temperature are suitable. Over the past four to five decades despite extensive and intensive research, many key questions in eutrophication science remain unanswered (Smith and Schindler, 2009). The causes of these blooms are very complex. Never-the-less, in practice there is a pressing need to provide sufficient clean water to our society. The need is urgent to develop reliable methods and strategies to control the algal blooms in our water sources, i.e., lakes or reservoirs. Such a method should be able to restore water quality of these water sources to an acceptable (i.e., no harmful blooms) level in a short of period, e. g. 3-5 years, and also it should be technically feasible, cost-effective and environment-friendly.

Therefore, a big question to ask is how to manage our water resources, and our target is to provide the society enough clean water to sustain their other activities. Any effective strategy of water management should be able to manage or mitigate the disasters caused by floods (too much), droughts (too little), deterioration of water quality (too dirty) and siltation (too turbid). The above mentioned clearly shows that all problems of water supply are directly or indirectly related to the contaminated particle management that affects either water quantity or water quality.

One such method exists (Yang, 2004) and its application is described below. After reviewing the existing problems in water management, Yang and Liu (2010) proposed an effective method to control water quality in lakes; the "separation, protection and prevention" or SPP strategy comes from the following facts:


ecosystem. Just like the carbon dioxide emission and climate change, human activities have dramatically increased the emission of nutrients, contributing to increase in phytoplankton biomass and even algal blooms formation in receiving water bodies, e.g. rivers, lakes, coastal waters and reservoirs. With rapid economic/development and population growth worldwide, harmful algal blooms have become more frequent, more extensive, and more

Algal blooms typically appear in slow moving water bodies with excess nutrients e.g. phosphorus, and nitrogen etc., when sunlight, turbulence, transparency, salinity and temperature are suitable. Over the past four to five decades despite extensive and intensive research, many key questions in eutrophication science remain unanswered (Smith and Schindler, 2009). The causes of these blooms are very complex. Never-the-less, in practice there is a pressing need to provide sufficient clean water to our society. The need is urgent to develop reliable methods and strategies to control the algal blooms in our water sources, i.e., lakes or reservoirs. Such a method should be able to restore water quality of these water sources to an acceptable (i.e., no harmful blooms) level in a short of period, e. g. 3-5 years,

Therefore, a big question to ask is how to manage our water resources, and our target is to provide the society enough clean water to sustain their other activities. Any effective strategy of water management should be able to manage or mitigate the disasters caused by floods (too much), droughts (too little), deterioration of water quality (too dirty) and siltation (too turbid). The above mentioned clearly shows that all problems of water supply are directly or indirectly related to the contaminated particle management that affects either

One such method exists (Yang, 2004) and its application is described below. After reviewing the existing problems in water management, Yang and Liu (2010) proposed an effective method to control water quality in lakes; the "separation, protection and prevention" or SPP

1. Algal blooms and siltation often appear in slowly moving water bodies. At the same nutrient level, fast moving water has less likelihood to induce massive algal blooms. Large-scale and sustained blooms are not a common occurrence if nutrient loading is very low, or blooms are governed by environmental factors (e.g. temperature, light extinction, nutrients), but equally important are the physical processes such as flow velocity, turbulence, mixing process and dispersion. Similarly, fast moving water has less siltation problems, all reservoirs/lakes are silted by high-sediment laden flows. Hence, it is important to separate clean water from water with too dirty and too turbid

2. For typical watersheds, rivers always play a major role in assimilating or carrying off municipal and industrial wastewater as well as runoff from the catchment. Reservoirs/Lakes receive a major portion of their pollutants/sediment from river inflows; therefore excessive wastewater/sediment inputs can cause serious ecological problems in the ecosystem. However, rivers also constitute the main clean water sources to a lake/reservoir. River water quality is heterogeneous spatially and temporally. In order to manage water quality in a lake, the temporal and spatial variation in water quality must be understood. The typical hydrograph for a catchment is simplified in Fig. 2 where Q is flow rate, Qr is runoff due to rainwater and

and also it should be technically feasible, cost-effective and environment-friendly.

severe (Hallegraeff, 1993, Heisler, et al. 2008).

water quantity or water quality.

waters.

strategy comes from the following facts:

groundwater without being polluted, Qw is the domestic and industrial wastewater discharge, Qs is the sediment discharge, Qa is the rate of wastewater from agriculture or the non-point source pollutant. The year-round rainwater is unsteady, and floods often appears in wet seasons, but wastewater rate from industry and domestic sources is relatively constant year-round even their concentrations in the rivers are not even after mixing. Inflow-river waters are heavily polluted in the dry period while pollutant concentrations are reduced during the wet (flood) period after mixing of clean rainwater with the domestic and industrial wastewater. But this does not mean that the wastewater concentration in flood period is always low as the first flush of storm often drives the non-point source pollutants to the waterways, thus the peak of Qa appears before the peak of Qr. Different from the agricultural wastewater, sediment discharge concentration is roughly proportional to the river flow, i.e., very high during wet season, very low in dry seasons.

3. Currently, throughout the world it is rare to find an integrated water resources management plan that can reduce the external nutrients, and at the same time mitigate flood disaster and solve the water shortage problems, i.e., simultaneously solve four problems of flooding (too much), droughts (too little), algal blooms (too dirty) and siltation (too turbid) for a given basin where reservoirs/lakes are located.

Based on these realizations, Yang and Liu (2010) proposed the following SPP strategy to manage different waters in a lake/reservoir:


The objectives of this chapter will be 1) to show how to manage the water and the particles it carries simultaneously, thus the floodwater is regulated for the use in drought seasons, and the lakes/reservoirs' storage capacity is protected with the damaged ecosystem being restored; 2) to compare the new strategy of water management with existing strategies, and the case studies will demonstrate whenever the SPP strategy is applied, the water related disasters can be mitigated, vice versa.
