Summary

Based on physico-chemical and biological analyses of the water in the river, Sharavathi River basin is categorized into most disturbed (Sharmanavathi, Haridravathi, Keshavapura, Gazni, Sampakai, Gudankatteholé), moderately disturbed (Muppanae, Talakalale Dam, Reservoir, Dabbe falls, Hosagadde) and least disturbed (Yenneholé, Hurliholé, Nittur, Valagere, Dobbod) zones. The disturbance is due to anthropogenic activities in the catchment, mainly agriculture. Presence of coliform bacteria at Sharmanavathi, Haridravathi, Keshavapura and Nandiholé indicates faecal contamination. Before construction of a dam at Gerusoppa, reports indicated that salinity concentration fell rapidly reaching a zero value at Hosad (about 5-6 km from the sea). Field measurements revealed salinity ingress up to Mutta, Balkur (about 15 km from sea). The concentration is highest during the high tide occurring in the morning.  It would be desirable to maintain a discharge (i.e. release from the power stations) to limit the salinity ingress. Soil samples were collected from 78 locations distributed all over the upper catchment and subjected to physico-chemical analyses. Soils are rich in organic matter and low in phosphate, nitrate and sulphate concentration, while pH ranged between 5.5-6.8. The sediments have low sulphate (0.19-0.68 mg/gm), nitrate (0.0-0.0007 mg/gm) and phosphate (0.00024-0.001 mg/gm) indicating close correlation between sediment and catchment soil. The sediment samples are rich in organic carbon and the elements like Na, K, Ca, Mg are found well within the prescribed standards. Bulk density of sediments in streams of the western region indicates porous condition (0.783-0.983 gm/cm3) while in the eastern side they are less porous (1.23-1.475 gm/cm3). 

Introduction

Water is essential for life and plays a vital role in the proper functioning of the earth's ecosystem. The pollution of water has serious impact on living creatures and can negatively affect the use of water for drinking, household need, recreation, fishing, transportation and commerce. Many factors affect the chemical, physical and biological characteristics of a water body. They may be either natural like geology/ weather or anthropogenic, which contribute to the point and non-point source of pollution. Developmental projects like construction of dams may change the quality of water as it involves blocking the natural flow. It impacts aquatic organisms and changes the nature of the stream itself. As water slows down and backs up behind a dam, various changes in its physico-chemical and biological characteristics take place. Water quality monitoring involves recording data about these various characteristics and usually involves analysing and interpreting these data. Monitoring helps to ensure that a particular water body is suitable for its determined use. 

Rivers in the world carry as much as three billion tonnes of material in solution and ten billion tonnes of sediment every year. The characterisation of sediments reflects the quality of the catchment area, through which the rivers flow. Sedimentation of a river, lake or reservoir is associated with its flow and also disturbs the water quality and aquatic ecosystem. Runoff from different sources result in different qualities of sediment and ultimately various changes take place. The sediment content may also vary from month to month depending on the season, while it may be negligible during the winter and summer months, it is maximum during the monsoon months.

Higher sediment delivery ratio (ratio between the amount of sediment yield and the gross erosion in watershed) is associated with smaller catchments. As one moves upstream, the drainage basin area decreases and the topographic factors that promote sediment delivery becomes more intensified resulting in higher sediment - delivery ratio. The actual rate of silting of a reservoir depends on many other factors, in addition to the rate of sediment production in the catchment area. They are, trap efficiency of the reservoir, ratio of reservoir capacity to total runoff, gradation of silt, method of reservoir operation etc. The trap efficiency of a reservoir is defined as the ratio of sediment retained in the reservoir and sediment brought by the stream. Damming the water also deposits the sediments that they carry. This causes sediment build up behind the dam, often changing the composition of the river.

The following factors affect sedimentation -

1. Extent of catchment area and the friable nature of the different zones.
2. Amount of sediment load in the rivers.
3. Type of rainfall and snowfall in each zone.
4. Mean monthly and annual run-off from catchment or sub-catchment.
5. Slope of each zone of catchment.
6. Vegetation in each zone of catchment.
7. Geological formation of each zone, estimated relative weathering and erosion with due regard to climatic conditions.
8. Presence of upstream reservoirs and extent of trapping of sediment therein.
9. Amount of sediment flushed out through sluices.
10. Degree of consolidation of accumulated sediment depending upon the extent of exposure to air, sun and wind.
11. Operation schedule of reservoir.

River Systems and Water Resources of Karnataka

The state has very good water resources in its numerous rivers, lakes and streams and to a certain extent groundwater. Seven river basins drain the whole state (The names and the areas drained are given in Table 1).

Table 1. River basins of Karnataka State.

Name of the Basin	Catchment Area (sq. km)	Total Area of the State (%)	Estimated Average Flow  (Million m3)
Krishna	1,13,271	59.06	27,500
Godavari	4,405	2.30	1,400
Cauvery	34,273	17.87	11,000
West-flowing rivers	26,214	13.68	57,000
North Pennar	13,610	3.61	900
South Pennar		1.95
Palar		1.54

The total catchment area of these rivers is 1,91,773 sq. km. and the estimated average flow is 97,800 million m3 (M cum). The Krishna and Cauvery river basins drain about 77% of geographical area of the state. Sharavathi, Netravathi, Varahi, Bedti (Gangavathi) and Aghanashini are the more important rivers, all of which have considerable hydroelectric potential. They arise in the west of the Ghats and flow into the Arabian Sea. The area of forests and hills has a rugged topography, characterised by deep ravines and steep hills rising to heights of 1,250 to 1,890 m, which are the source of all the east and west-flowing rivers of the state.

Objectives

• Assess the status of water and sediment by physico-chemical and biological characterization.
• Explore suitable watershed management and conservation strategies for their long-term sustenance.

Sampling and Analysis of Water:  Water is a dynamic system and hence its characteristic quality changes with time and place. Water samples were collected at regular intervals to identify their characteristics and the changes in their quality. A total of 40 water samples (16 in the upstream and 24 in the downstream) were collected from various locations encompassing the entire catchment area. Precautions were taken while handling the collected samples to ensure its integrity.

Sampling Sites - Upper catchment: For physico-chemical and biological characterisation, monthly samples were collected at (numbers in the square brackets indicate sampling sites):

• Area where principal feeder tributaries Sharavathi [1] (Nagara), Sharavathi [2], Sharmanavathi or Mavinaholé  [3], Haridravathi [4] and Yenneholé [10] that meet the reservoir.
• Central part of reservoir near Holébagilu [8] to get a general quality of the water.
• Outlet [7] from the Linganamakki dam.
• Other minor tributaries like Hurliholé [9] and Keshawapura [14] and Nandiholé [15], Valagere [11], Nittur [13] and Sampekai [16].
• At Talakalale dam, a balancing reservoir [6], Muppane [5] and Madenur dam [12] to get a comparative water quality status over the other sampling sites.

Table 2 gives the water sampling sites and their respective co-ordinates in the upper catchment of Sharavathi river basin.

Table 2. Water sampling representative sites of the Sharavathi upper catchment.

Sub-basin	Sampling Sites	Latitude (°N)	Longitude (°E)
Hilkunji (US8)	Sharavathi (Nagara) [1]	13.8267	75.0601
Sharavathi (US4)	Sharavathi [2]	13.8789	75.065
Mavinaholé (US3)	Sharmanavathi [3]	13.9855	75.0822
Haridravathi (US2)	Haridravathi [4]	14.0384	75.1207
Yenneholé (US5)	Muppane [5]	14.1083	74.7902
Mavinagundi (US5)	Talakalale [6]	14.1853	74.7863
Mavinagundi (US5)	Dam outlet [7]	14.1917	74.8268
Linganamakki (US9)	Reservoir [8]	14.0756	74.8977
Hurliholé (US6)	Hurliholé [9]	13.9914	74.8672
Yenneholé (US5)	Yenneholé [10]	14.0417	74.759
Linganamakki (US9)	Valagere [11]	14.0624	74.8452
Linganamakki (US9)	Madenur Dam [12]
Linganamakki (US9)	Nittur [13]	13.9371	74.9139
Haridravathi (US2)	Keshawapura [14]	14.0191	75.1215
Nandiholé (US1)	Nandiholé [15]	14.0426	75.1254
Linganamakki (US9)	Sampekai [16]	14.048	75.0467

Sampling sites - Lower catchment: In the lower catchment among the 7 sub-basins, 20 localities were selected for water sampling (Table 3).

Table 3. Water sampling representative sites of the downstream catchment.

Sub Basin	Sampling locations	Latitude (°N)	Longitude (°E)
Dabbe falls (DS4)	Hebbankeri [2]
Dabbe falls (DS 4)	Dabbe falls [1]	14.13747	74.74158
Magod (DS 3)	Hosagadde [3]	14.17009	74.54848
Magod (DS 3)	Dabbod [4]
Magod (DS 3)	Magodholé [5]	14.22377	74.59595
Magod (DS 3)	Gazni/ Hennur [6]	14.21883	74.53471
Magod (DS 3)	Heggar [7]	14.23294	74.52602
Chandavar (DS 1)	Chandavar [21]
Chandavar (DS 1)	Gudankatteholé [22]	14.38152	74.44321
Chandavar (DS 1)	Badagani [23]	14.35294	74.42194
Gudankattehole (DS 7)	Bhaskeri [8]	14.3027	74.48524
Haddinabal (DS 2)	Chandubana [9]	14.32452	74.58300
Haddinabal (DS 2)	Haddinabal [10]	14.28523	74.51153
Haddinabal (DS 2)	Mavinaholé [11]	14.24546	74.61644
Haddinabal (DS 2)	Mahasathi [12]	14.26296	74.68116
Haddinabal (DS 2)	Vatehalla [13]	14.27035	74.69153
Magod (DS 3)	Upponi location 1 [14]	14.23432	74.60058
Magod (DS 3)	Upponi village loc 2 [15]	14.23167	74.58934
Kathlekan (DS 6)	Kathlekan [16]	14.27267	74.74788
Mavinagundi (DS 5)	Mavinagundi [17]	14.24380	74.81250
Mavinagundi (DS 5)	Jog lower [18]	14.22767	74.8120
Mavinagundi (DS 5)	Jog upper [19]	14.22973	74.81355
Mavinagundi (DS 5)	Joginamatha [20]	14.23024	74.82361

Sampling Procedure

• Polyethylene containers
• The container was rinsed with HCl followed by distilled water.
• Before being filled with the sample, the container was first rinsed with the sample.
• The samples were collected by directly immersing the container in the water, and it was closed properly using appropriate stoppers.
• A number of parameters like pH, temperature, colour, and dissolved oxygen were measured at the sampling sites immediately after collection of the sample.
• After the addition of preservatives like Toluene (to check microbial action) the samples were transported to the laboratory for further analysis (physico-chemical and biological).

Physico-Chemical and Biological Analysis

Physico-chemical and biological parameters for monthly samples were analysed according to the standard methods provided by National Environmental Engineering Research Institute NEERI and American Public Health Association (APHA) and the values were compared with World Health Organization and Indian Standard Specifications (IS: 1050-1983; IS: 2490 –1982).

The following physico-chemical and biological parameters were measured at various representative sites within the Sharavathi catchment area at one-month intervals. Table 4 gives physico-chemical and biological parameters and its respective method of analysis.

Table 4. Water quality parameters and its method of analysis.

Physical Parameter	Method of Analysis
Temperature (°C)	Mercury Thermometer
Transparency  (cm)	Secchi Disk
Total Dissolved Solids (mg/L)	Electrometric
Total Suspended Solids (mg/L)	Gravimetric
Turbidity (NTU)	Jal Tara Water Testing Kit
Colour	Visual Comparison
Odour	Olfactory sensing
Chemical Parameter
pH	Electrometric
Conductivity (mS/cm)	Electrometric
Acidity (mg/L)	Titrimetric
Alkalinity (mg/L)	Titrimetric
Chloride (mg/L)	Argentometric
Residual chlorine (mg/L)	Visual Colour Comparison
Total Hardness (mg/L)	Titrimetric
Calcium hardness (mg/L)	Titrimetric
Magnesium hardness (mg/L)	Titrimetric
Dissolved oxygen (ppm)	Electrometric
Fluoride (mg/L)	Jal Tara Water Testing Kit
Ammonia (mg/L)	Visual Colour Comparison
Sodium (mg/L)	Flame Photometer
Potassium (mg/L)	Flame Photometer
Sulphates (mg/L)	Spectrophotometer
Iron (mg/L)	Visual Colour Comparison
Nitrates (mg/L)	Phenoldisulphonic Acid
Phosphates (mg/L)	Ammonium molybdate
Biological Parameter
Coliform	Visual Comparison

Significance of Various Physico-chemical Parameters

Physical Parameters

Temperature: The rate of chemical and biological processes in surface water, especially oxygen levels, photosynthesis and algal production, are strongly influenced by temperature. Temperature readings are used in the calculations of various forms of alkalinity and salinity. In limnological studies, water temperature is often taken as a function of depth. Increase in temperature over 40°C in natural water tends to accelerate chemical reactions, lower solubility of gases like oxygen, carbon dioxide, nitrogen and methane, amplify taste and odour, and increase metabolic activity of organisms.

Impinging solar radiation and atmospheric temperature brings about spatial and temporal changes in water temperature setting up convection currents and thermal stratification. Temperature has direct influence on various parameters like alkalinity, salinity, dissolved oxygen, electrical conductivity etc. In an aquatic system, these parameters affect the chemical and biological reactions such as solubility of oxygen, carbon-dioxide, carbonate-bicarbonate equilibrium, increases in metabolic rate and affect the physiological reactions of organisms, etc. Water temperature is important in relation to fish life. The temperature of drinking water has an influence on its taste. 

Transparency (Light Penetration): Transparency is a characteristic of water that varies with the combined effect of colour and turbidity. It measures the light penetrating through the water body.

Total Dissolved Solids: Dissolved solids are in dissolved state in solution (having particle size less than 10-9m). Low concentrations of dissolved substances have no significant influence on the water quality but at high concentrations impair the water quality and suitability of water for various applications such as domestic, industrial and agricultural purposes. It has an overall effect on the living creatures like humans, aquatic and terrestrial organisms. Excessive concentrations increase water turbidity, affects photosynthesis, absorbs more heat, enrich nutrient status of water etc. It helps in understanding level of turbidity and hardness of water. They cause laxative effects in humans and when present in irrigation water enrich the soil making it saline.

Total Suspended Solids: Solids that remain in suspension like silt, sand, clay and phytoplankton etc., form the total suspended solids. Similar to TDS, it interferes in the quality of the water.

Turbidity: The substances not present in the form of true solution can cause turbidity in water. True solution have a particle size of less than 10-9 m and any substances having more than this size will produce turbidity. Suspended solids and colour are the main interference for transparency. The clarity of a natural water body is a major determinant of the condition and productivity of the system. Turbidity value above 10 NTU would affect these processes and transparency. It restricts the penetration of light giving rise to reduced photosynthesis and affects the aesthetics. High levels of turbidity can protect microorganisms from the effects of disinfection and can stimulate bacterial growth. The transparency and turbidity are inversely related to each other, if turbidity is more, transparency is less and vice versa.

Turbidity is an expression of optical property; wherein light is scattered by suspended particles present in water (Tyndall effect). Suspended and colloidal matter such as clay, silt, finely divided organic and inorganic matter, plankton and other microscopic organisms cause turbidity in water. Turbidity affects light penetration, absorption properties and aesthetic appearance of a water body. Increase in the intensity of scattered light results in higher values of turbidity.

Increased turbidity associated with reduction in suspended matter and microbial growth makes water unfit for drinking and other purposes. High turbidity levels in natural waters makes water warmer as suspended particles absorb more heat from the sunlight resulting in low dissolved oxygen concentrations. Turbidity also restricts light penetration for photosynthesis and hence a major determinant of the condition and productivity of the natural water body.

Colour: In natural water, colour is due to the presence of humic acids, fulvic acids, metallic ions, suspended matter, plankton, weeds and industrial effluents. Colour is removed to make water suitable for general and industrial applications.

Odour: Odour is an in situ parameter and temperature dependent. It impairs the water quality creating unhygienic conditions and is a pollution indicator. Odour is imparted to water due to the presence of volatile and dissolved organic and inorganic components such as organic matter, phytoplankton, contamination due to domestic sewage and industrial effluents, dissolution and presence of gases in water like NH3, H2S etc.

Chemical Parameters

pH: pH has its great influence on the chemical and biological properties of liquids, hence its determination is very important. In natural water, pH is governed by the equilibrium between carbon dioxide/bicarbonate/carbonate ions and ranges between 4.5 and 8.5 although mostly basic. It tends to increase during day largely due to the photosynthetic activity (consumption of carbon dioxide) and decreases during night due to respiratory activity. Wastewater and polluted natural waters have pH values lower or higher than 7 based on the nature of the pollutant.

Electrical Conductivity: Conductivity (specific conductance) is the ability of water to conduct an electric current. It is measured in milli-Siemens per cm and depends on the total concentration, mobility, valence of ions and the temperature of the solution. Electrolytes in a solution disassociate into positive (cations) and negative (anions) ions and impart conductivity. Most dissolved inorganic substances are in the ionised form in water and contribute to conductance. The conductance of the samples gives rapid and practical estimate of the variation in dissolved mineral content of the water supply.

Acidity: Acidity of a liquid is its capacity to denote H+ ions. Since most of the natural waters and sewage are buffered by carbon dioxide - bicarbonate system, the acidity present due to free CO2 has no significance from public health point of view. Water containing mineral acidity (due to H2SO4, HNO3 and HCl) is unacceptable. Further, acid waters pose problems of corrosion and interfere with water softening.

Alkalinity: The alkalinity of water is the measure of its capacity to neutralise acids. The alkalinity of natural waters is due to the salts of carbonates, bicarbonates, borate, silicates and phosphates along with the hydroxyl ions in the free state. However, hydroxide, carbonate and bicarbonate cause the major portion of the alkalinity in the natural water, which may be ranked in the order of their association with high pH values.

Chlorides: The presence of chlorides in natural waters can mainly be attributed to dissolution of salt deposits in the form of ions (Cl-). Otherwise, high concentrations may indicate pollution by sewage or some industrial wastes or intrusion of seawater or other saline water. It is the major form of inorganic anions in water for aquatic life. High chloride content has a deleterious effect on metallic pipes and structures, as well as agricultural plants. In natural fresh waters, high concentration of chlorides is regarded as an indicator of pollution due to organic wastes of animal origin (animal excreta have higher chlorides along with nitrogenous wastes). Domestic sewage and industrial effluents also bring chlorides into the water. Chloride content above 250 mg/L makes water salty. However, a level up to 1000 mg/L is safe for human consumption. High level results in corrosion and non-palatability.

Residual Chlorine: Free chlorine reacts readily with ammonia and certain nitrogenous compounds to form combined chlorine. With ammonia, chlorine reacts to form the chloroamines; monochloroamine, dichloroamines and nitrogen trichloride. The presence and concentrations of these combined forms depend chiefly on pH, temperature, initial chlorine to nitrogen ration, absolute chlorine demand and reaction time. Both free and combined chlorine may present simultaneously. Combined chlorine in water supplies may be formed during the treatment of raw water containing ammonia or ammonium salt. Chlorinated wastewater effluents as well as certain chlorinated industrial effluents, normally contain combined chlorine.

Total Hardness: Hardness is due to the presence of multivalent metal ions, which come from minerals dissolved in the water. In fresh water the primary ions are calcium and magnesium; however iron and manganese may also contribute. Depending on pH and alkalinity, hardness of about 200 mg/L can result in scale deposition, particularly on heating. Soft waters with a hardness of less than about 100 mg/L have a low buffering capacity and may be more corrosive to water pipes.

Calcium Hardness: The presence of calcium (fifth most abundant) in water results from passage through or over deposits of limestone, dolomite, gypsum and other calcium bearing rocks. Calcium contributes to the total hardness of water and is an important micronutrient in aquatic environment and is especially needed in large quantities by molluscs and vertebrates.

Magnesium Hardness: Magnesium is a relatively abundant element in the earth's crust, ranking eighth in abundance among the elements. It is found in all natural waters and its source lies in rocks, generally present in lower concentration than calcium. It is also an important element contributing to hardness and a necessary constituent of chlorophyll. Its concentration greater than 125 mg/L can influence cathartic and diuretic actions.
 
Dissolved Oxygen: Oxygen dissolved in water is a very important parameter in water analysis as it serves as an indicator of the physical, chemical and biological activities of the water body. The two main sources of dissolved oxygen are diffusion of oxygen from the air and photosynthetic activity. Diffusion of oxygen from the air into water depends on the solubility of oxygen, and is influenced by many other factors like water movement, temperature, salinity, etc. Photosynthesis, a biological phenomenon carried out by the autotrophs, depends on the plankton population, light condition, gases, etc. Oxygen is considered to be the major limiting factor in water-bodies with organic materials. If its value is less than 3 mg/L, the metabolic processes that produce energy for growth and reproduction get affected. Oxygen levels that remain below 1-2 mg/L for a few hours can result in large fish kills.

Fluoride: Fluorides have dual significance in water supplies. High concentration causes dental fluorosis and lower concentration (< 0.8 mg/L) causes dental caries. A fluoride concentration of approximately 1 mg/L in drinking water is recommended. They are frequently found in certain industrial processes resulting in fluoride rich wastewaters. Significant sources of fluoride are found in coke, glass and ceramic, electronics, pesticide and fertiliser manufacturing, steel and aluminium processing and electroplating industries.

Ammonia: Ammonia is produced by the microbial degradation of organic matter. It appears therefore, in many grounds as well as surface waters. Concentrations of ammonia above a certain level in water; polluted either due to sewage or industrial wastes, is toxic to fish.

Sodium and Potassium: Sodium is one of the most abundant and a common constituent of natural waters. The sodium concentration of water is of concern primarily when considering their solubility for agricultural uses or boiler feed water. The concentration ranges from very low in the surface waters and relatively high in deep ground waters and highest in the marine waters.

Potassium is found in low concentrations (<10 mg/L) in natural waters since rocks, which contain potassium, are relatively resistant to weathering. It is usually found in ionic form and the salts are highly soluble. Though found in small quantities it plays a vital role in the metabolism of fresh water environment.

Sulphates: Sulphates are commonly found in all natural waters, particularly those with high salt content. Besides industrial pollution and domestic sewage, biological oxidation of reduced sulphur also adds to sulphate content. It is soluble in water and imparts hardness with other cations. Sulphate causes scaling in industrial water supplies, and odor and corrosion in wastewater treatment processes due to its reduction to H2S. Its main source is industrial discharge that contains sulphate salts and domestic wastes (heavy use of detergents). When water containing magnesium sulphate at levels about 1000 mg/L acts as a purgative in human adults, lower concentration (below 150 mg/L) may still affect new users and children. Taste threshold concentration for the most prevalent sulphate salts are 200 to 500 mg/L for sodium sulphate, and 400 to 600 mg/L for magnesium sulphate. 

Iron: Iron is the fourth most abundant element by weight in the earth's crust. In water it occurs mainly in the divalent and trivalent state. Iron in surface water is generally present in the ferric state. The concentration of iron in well-aerated water is seldom high, but under reducing condition, which may exist in some ground water, lake and reservoir and in the absence of sulphate and carbonate, high concentration of soluble ferrous iron may be found. The presence of iron in natural water can be attributed to the dissolution of rocks and minerals, acid mine drainage, landfill leachates, sewage or engineering industries. Iron is an essential element in human nutrition. It is contained in a number of biologically significant proteins, but ingestion in large quantity results in hemochromatosis where in tissue damage results from iron accumulation.

Nitrates: The nitrate ion is the common form of combined nitrogen found in surface waters. By denitrification process, it may be bio-chemically reduced to nitrite under anaerobic conditions. The significant sources of nitrates are chemical fertilizers from cultivated lands, drainage from livestock feeds, as well as domestic and industrial sources. Natural waters in their unpolluted state contain only minute quantities of nitrates. The stimulation of plant growth by nitrates may result in eutrophication, especially due to algae. The subsequent death and decay of plants produce secondary pollution. Nitrates are most important for biological oxidation of nitrogenous organic matter. Certain nitrogen fixing bacteria and algae have the capacity to fix molecular nitrogen in nitrates. The main source of polluting nitrates is the domestic sewage let into water bodies. Nitrates may find their way into ground water through leaching from soil and at times by contamination. Waters with high concentrations (>45mg/L) can represent a significant health risk. Beyond this value methemoglobinemia takes place.

Phosphates: Phosphate’s role in promoting plant growth actually makes it a dangerous pollutant when dumped in excessive quantities into aquatic ecosystems. The rate at which plants can grow and reproduce is limited by the amount of usable phosphate in the soil or water (for aquatic plants). When extra phosphorous was added to water due to anthropogenic activities, it creates a condition called eutrophication that can wipe out aquatic ecosystems. Eutrophication is characterized by a rapid growth in the plant population (an algal bloom). The bacteria that decompose the dead plants use oxygen, and eventually burn up so much that not enough remains to support fish, insects, mussels, and other animals, leading to a massive die-off. The presence of phosphates in virtually every detergent, including household cleaners and laundry soap, fertilizer run-off from agriculture and landscaping, decomposition of organic matter continues to be a major source of phosphate pollution. Animal wastes can also add significant amounts of phosphate to water. In most surface waters, concentration of phosphorus ranges from 0.005 to 0.020 mg/L PO4- P.

Biological Parameters

Biological Coliform: Storm water combined with sanitary sewers can flush bacteria laden water into streams. Total coliform bacteria are a collection of relatively harmless microorganisms that live in large number in the intestine of man and warm and cold-blooded animals. They aid in the digestion of food. A specific sub-group of this collection is the faecal coliform bacteria, the most common member being Escherichia coli (E. coli). These organisms may be separated from the total coliform group by their ability to grow at elevated temperatures and are associated with the fecal material of warm-blooded animals. The presence of faecal coliform bacteria in aquatic environment indicates that the water has been contaminated with the faecal material. At the same time the pathogens or diseases producing bacteria or virus that are co-existing with faecal material might also contaminate the water. This results in the outbreak of water born diseases like typhoid, dysentery, diarrhoea, viral and bacterial gastroenteritis and hepatitis A.

Sampling and Analysis of Sediments

The sediment from water bodies is usually collected by dredge and scoop and for deeper layer special boring machine is used. In this study samples were collected in polyethylene bags by means of scoop and immediately transported to the laboratory for further physico-chemical analysis.

The sediment sampling sites were (1) Sharavathi 1 (Nagara), (2) Sharavathi 2, (3) Sharmanavathi, (4) Haridravathi, (5) Muppane, (6) Linganamakki reservoir, (7) Hurliholé, (8) Yenneholé, (9) Valagere, (10) Nittur, and (11) Sampekai with corresponding longitude and latitude as given for water sampling sites (Table 2).

Results and Discussion of Water Analysis

Physical Parameters

Temperature: The temperature of water in upper catchment ranged from 22°C to 34.5°C. In sampling site 8 (Linganamakki Reservoir), water temperature was higher than any other site (Min: 24.0°C Max: 34.5°C). This is a characteristic feature of a lacustrine ecosystem (Table 5).

Table 5. Temperature (°C) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	24.5	29.5	29	28			31	34.5		28.9
Mar-01	30.1	30.5	30.1	31.6	30.6	28	26.5	34	27.9	29.2	29.6	28.3	29.1
Apr-01	28.1	26.5	26.5	29	29	29.5	31	31.5	28	31	29	30.5	30.5
May-01	30.1	30.5	30.1	31.6	31	30.5	29.2	34	29	27.5	31	28.9	30
Jul-01	23.8	24	23.9	24.3	23.3	24.1	24.8	26	24.5	23.4	25.5	24.5		24.1	24.4	25
Aug-01	23.4	27	26	26	25.9	26	25.8	26	24.5	24	26	25		27	26.5	26
Sep-01	26	29	25.5	26.5	27	25.5	27	26.5	27.5	28	27	28	27.5	27.5	27	27
Oct-01	28	31	27	28	27	25	28.5	27	27	28	27.5	27.5	28	29	28	26
Nov-01	26	26	25	29	28	26	28	27	26	29	28	28	28	26	28	28
Dec-01	25.5	24	22	24	26	25	24	25	24	25	25	25.5	26	24	24	27
Jan-02	24	25	23	25	26	25	24	25	25	27	25		25	22	25	29
Feb-02	25	27	29	30	27	25	26	27	27	27	28		28			28
Mar-02	29	29	27	28	26	23	25	24.5	27	26	25		27
Apr-02	30	29	28	28	27	25	27	26	28	27	26		28

In downstream, water temperature ranged from 20°C - 36°C (Table 6). Values obtained are well within the limits provided by Indian Standards Specifications (NEERI).

Table 6. Water temperature in downstream localities.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02			28	29	28	28		27	27	27	26
Dec-02			28	27	28	28		27	27	27	24
Jan-03			28	26	28	28	27	29	27	29	28
Feb-03				30	30	29	28	29	29	31	32
Mar-03				33	33	32	30		31	34	33
April-03				33	34	33	31		31	31	34
May-03				32	32	31	30		35	31	33
Jun-03			29	29	29	29	28	28		28	28

Table 6. Water temperature in downstream localities (cont...).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	29	26	27	28	22	22	22			29	28	30
Dec-02	28	24	28	28	20					27	28	30
Jan-03	29	27	28	30	21	28		27		30	29	26
Feb-03	33	35	30	30	27	28		32	26		30	31
Mar-03	32	30	30		28	28		32	26		29	31
April-03	34	36	32		26	30		32	27		30	32
May-03	32	33	31		26			30	28		30	32
Jun-03	30	28	28		24			25	24		34	27

Transparency and Turbidity

In the upper catchment, transparency varied from 3 cm to 284 cm and turbidity value fluctuated from <5 –125 NTU (Table 7 and 8). Turbidity exceeded NEERI limits, mainly in Hosanagara and some part of Sagar due to agricultural runoff during monsoon.

Table 7. Transparency (cm) in the water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	85	80	40	80			27.5	65		76
Mar-01	80	100	124	74	92	59	73	98	73	93	57	47	56
Apr-01	64	65	76	56	67	55	60	75	67	67	43	70	45
May-01	65	43	89	65	92	59	73	70	73	65	67	60	56
Jul-01	23	16	14	8	50	45	50	43	34	53	45	42		8	8	4
Aug-01	12	12	8	5	30	50	30	37	32	50	42	40		5	3	3
Sep-01	18	15	12	6	25	35	20	75	45	30	45	30	30	7	5	4
Oct-01	53	35	38	3	50	150	65	160	80	80	80	75	32	8	3	35
Nov-01	58	58	38	15	112	166	82	148	70	39	39	39	82	18	15	38
Dec-01	58	38	38	13	97	130	70	280	97	80	148	24	80	10	10	58
Jan-02	80	65	58	23	90	284	82	284	90	35	90		145	20	35	35
Feb-02	82	75	42	12	82	284	80	284	90	35	70		125			15
Mar-02	72	48	15	15	82	284	72	72	58	72	10		130
Apr-02	75	50	18	15	80	284	70	75	45	70	12		110

Table 8. Turbidity (NTU) in water samples of the Sharavathi upstream

Months

Sampling sites

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Feb-01

<10

<10

<10

25

<10

<10

Mar-01

<10

<10

<10

>50

<10

<10

<10

<10

<10

<10

<10

<10

<10

Apr-01

<10

<10

<10

>50

<10

<10

<10

<10

<10

<10

<10

<10

<10

May-01

25

<10

<10

>50

<10

<10

<10

<10

<10

<10

<10

<10

<10

Jul-01

50

35

30

60

<10

<10

<10

<10

<10

<10

<10

<10

75

75

50

Aug-01

75

50

20

75

<5

<5

12

<5

<10

<10

<10

<10

125

100

50

Sep-01

25

25

20

75

<10

<10

<10

<10

<10

<10

<10

<10

<10

60

75

45

Oct-01

<10

15

20

20

<5

<5

<5

<5

<5

<5

<5

<5

<5

50

70

<10

Nov-01

<10

12

15

20

<5

<5

<10

<5

<5

<5

<5

<5

<5

30

30

15

Dec-01

<10

<10

15

20

<5

<5

<10

<5

<5

<5

<5

<5

20

25

20

15

Jan-02

20

<5

15

30

<10

<10

<10

<10

<10

<10

<10

<10

25

10

20

Feb-02

10

5

20

40

7

<5

5

<10

<5

<10

<10

<10

45

Mar-02

10

5

20

40

7

<5

5

<10

<5

<10

<10

<10

45

Apr-02

10

10

15

25

7

<5

<5

<10

<5

<10

<10

<10

In lower catchment,turbidity was in the range of 10 - 100 NTU. At Dabbe [DS4], Joginamutt [DS5] and Jog upper [DS5] it was 25-50 NTU, <100 NTU and 10 – 25 NTU respectively and exceeded the standard limit of 10 NTU. It was due to runoff from the catchment area and also due to the obstruction of water for agriculture leading to the increased sediment loads and phyto-productivity in the stream.

Total Dissolved Solids and Total Suspended Solids

In Sharavathi upstream regions, the total suspended solids ranged from 21.3 to 110 mg/L and total dissolved solids 13.77 – 84.03 mg/L (Table 9 and 10). The results showed that TSS concentration exceeds the limits, due to siltation from storm and agricultural runoff (mainly at Hosanagara region) whereas TDS values are within the limits provided by NEERI.

Table 9. Total Suspended Solids (mg/L) in the water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	62	41.3	21.3	52			52	40		38.6
Mar-01	40	54	30	41	32	50	26	32	40	64	60	35	40
Apr-01	54	39	68	37	32	37	68	35	46	52	40	52	27.1
May-01	82	80	74	67	40	26	67	74	32	48	71	57	85
Jul-01	65	78	76	110	40	35	65	55	65	45	55	55		102	108	58
Aug-01	80	80	82	110	45	40	70	58	68	50	58	60		100	106	55
Sep-01	82	83	80	108	50	50	75	55	70	55	60	65	55	101	105	60
Oct-01	81	83	81	106	49	51	72	51	69	53	62	62	51	101	102	58
Nov-01	85	85	82	108	55	55	75	55	75	55	65	65	55	105	105	65
Dec-01	75	80	80	100	52	50	72	52	72	53	59	60	54	100	98	61

Table 10. Total Dissolved Solids (mg/L) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Aug-01	26.12	36.76	35.8	46.24	20.99	23.85	27.3	16.32	16.12	17.2	18.59	20		44.3	18.16	18.5
Sep-01	28.14	30.95	37	45.3	14.5	15.95	17.85	17.9	18	15	18.9	18	20	57	36	18.5
Oct-01	28.38	30.69	36.97	46.4	17.5	15.2	20.3	17.65	17.6	14.25	17.5	20.56	22.48	44	42.65	41.71
Nov-01	31.27	32.98	41.38	53.56	15.37	16.63	21.31	18.12	18.38	15.41	18.19	40.72	16.62	60.58	60.93	42.2
Dec-01	33.1	35.1	41.85	56.13	16.11	17.39	18.75	19.09	19.05	21.8	19.1	19.23	17.99	64.03	64.45	42.18
Jan-02	26.95	22.95	42.15	57.1	15.55	16.9	17.8	21.07	21.65	27.5	24.9		20.37	52.95	54.9	45.5
Feb-02	21.85	27.83	41.75	59.94	13.77	14.47	15.07	15.08	21.73	25.5	17.96		16.25			40.13
Mar-02	26.85	33.05	78.34	84.03	19.2	20.34	20.09	22.29	30.51	26.29	24.17		30.25
Apr-02	27.4	80.8	110	60.83	20.02	21.6	22.52	23.68	32.38	32.38	24.49	26.54	33.96

In downstream, however, except in the sites near to confluence of Sharavathi into Arabian sea (Haddinabal, Gudankateholé and Badagani), all other localities had TDS values in the stipulated USEPA range of 500mg/L (Table 11).  In Haddinabal, Gudankateholé and Badagani, TDS ranges between 24.81 – 15,090 mg/L. This indicated the brackish quality of water in the region.

Table 11. Total Dissolved Solids (mg/L) in the water samples of the Sharavathi downstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	18.83		22.27	20.26	21.72	20.62		24.31	22.22	24.81	25.95
Dec-02	19.99	30.22	21.78	20.38	21.68	21.22		26.01	23.83	26.34	25.04
Jan-03	24.52	30.9	24.33	29.32	24.26	36.14	23.95	29.53	31.64	1.21*	26.66
Feb-03	29.44			38.29	22	38.89	20.78	41.92	36.86	2.17*	28.53
Mar-03	25.97	36.3		37.26	25.97	39.9	20.93		45.81	1.43*	27.85
April-03	28.11	38.71		36.79	26.89	38.17	21.8		41.26	1.79*	25.7
May-03	29.22	57.95		42.93	23.36	40.44	24.2		77.37	2.20*	26.3
Jun-03	21.24		26.22	25.75	28.23	27.92	30.72	34.91		79.23	32.02

Table 11. Total Dissolved Solids (mg/L) in the water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	18.77	27.77	17.71	17.51	19.6	26.36	22.19			19.05	25.24	1.56*
Dec-02	18	30.2	16.2	16.8	21.4					19.71	27.04	6.35*
Jan-03	19.91	41.77	19.49	19.83	27.34	38.42		27.89		21.46	56.5	14.42*
Feb-03	21.14	51.28	20.13	21.45	28.13	43.3		31.95	30.44		95.31	14.32*
Mar-03	20.33	67.82	23.71		36.2	46.21		33.75	32.1		547.2	14.42*
April-03	20.34	72.88	21.23		33.51	46.88		34.07	31.41		1.047 *	15.09*
May-03	21.04	87.98	22.45		33.51			34.83	29.78		11.1 *	14.89*
Jun-03	20.53	39.34	22.32		25.36			31.71	21.45		224.3	5.04*

Colour
Pure water has no colour, but the presence of soluble or insoluble, organic or inorganic matter will impart greenish blue, green, greenish yellow, yellow or brown colour to water. Different species of phytoplankton and zooplankton also impart colour. A dark or blue green colour can be caused by blue green algae, yellow-brown by diatoms or dinoflagellates and red and purple by zooplankton such as Daphnia or Copepods. Colour must be removed to make water suitable for general and industrial applications.

In upstream, the water was colourless to brownish green. Brown and brownish green colours were recorded during monsoon due to colloidal suspension of silts from erosion (Table 12). Similar colouration was also observed in the downstream. In streams like Chandubanu, Vatahalla, Hennur, Hossagadde, Bhaskere, it was transparent, colourless and odourless, whereas in Haddinabal it was greenish due to stagnation. In Dabbod, generally water was transparent and colorless, but during agricultural activities it turned slightly turbid and exceeded the permissible limits for turbidity (February, March and April).

Table 12. Coloration of water samples from the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5
Feb-01	Colour less	Colour less	Colour less	Colour less	Colourless
Mar-01	Colour less	Colour less	Colour less	Colour less	Colourless
Apr-01	Colour less	Colour less	Colour less	Colour less	Colourless
May-01	Colour less	Colour less	Colour less	Colour less	Colourless
Jul-01	Brownish	Brownish	Brownish	Brownish	Colourless
Aug-01	Brownish	Brownish	Brownish	Brownish	Colourless
Sep-01	Brownish	Brownish	Brownish	Brownish	Colourless
Oct-01	Colourless	Brownish	Light brown	Brownish	Colourless
Nov-01	Colourless	Colourless	Light green	Brownish green	Colourless
Dec-01	Colourless	Light Brown	Light Brown	Brownish	Colourless
Jan-02	Greenish	Colour less	Light Brown	Brownish green	Colourless
Feb-02	Light Brown	Colour less	Light Brown	Brownish	Colourless
Mar-02	Slight Green	Light Brown	Brownish Green	Slight green	Colourless
Apr-02	Light Brown	Light Brown	Light Brown	Slight green	Colourless

Table 12. Coloration of water samples from the Sharavathi upstream. (Cont...)

Months	Sampling sites
	6	7	8	9	10
Feb-01	Colour less	Colour less	Colour less	Colour less	Colour less
Mar-01	Colour less	Colour less	Colour less	Colour less	Colour less
Apr-01	Colour less	Colour less	Colour less	Colour less	Colour less
May-01	Colour less	Colour less	Colour less	Colour less	Colour less
Jul-01	Colour less	Light brown	Light brown	Light brown	Colour less
Aug-01	Colour less	Light brown	Light brown	Light brown	Colour less
Sep-01	Colour less	Light brown	Light brown	Light brown	Colour less
Oct-01	Colourless	Colourless	Green	Colourless	Colourless
Nov-01	Colourless	Colourless	Bluish green	Colourless	Colourless
Dec-01	Colourless	Light Green	Light Green	Colourless	Light Green
Jan-02	Slight green	Greenish	Colour less	Colour less	Brownish
Feb-02	Slight green	Light brown	Colour less	Colour less	Brownish
Mar-02	Greenish	Greenish brown	Light Green	Brownish green	Brownish
Apr-02	Slight green	Light brown	Light Green	Brownish green	Light brown

Table 12. Coloration of water samples from the Sharavathi upstream. (Cont...)

Months	Sampling sites
	11	12	13	14	15	16
Feb-01	Colour less	Colour less	Colour less
Mar-01	Colour less	Colour less	Colour less
Apr-01	Colour less	Colour less	Colour less
May-01	Colour less	Colour less	Colour less
Jul-01	Light brown	Light Brown		Brownish	Brownish	Brownish
Aug-01	Light brown	Light Brown		Brownish	Brownish	Brownish
Sep-01	Light brown	Light Brown	Light brown	Light Brown	Brownish	Light Brown
Oct-01	Colourless	Colourless	Light brown	Brownish	Brownish	Brownish
Nov-01	Colourless	Colourless	Colourless	Green	Brownish green	Brownish green
Dec-01	Colourless	Colourless	Light brown	Brownish green	Brownish	Light Brown
Jan-02	Light Green		Light brown	Green	Green	Brownish green
Feb-02	Brownish		Colourless			Brownish green
Mar-02	Brownish		Colourless
Apr-02	Light brown		Colourless

Electrical conductivity

The electrical conductivity in the upper catchments of Sharavathi River ranged from 0.003 to 0.44 mS/cm (Table 13). Values obtained are well within the limits provided by Indian Standards Specifications (NEERI).

Table 13. Electrical conductivity (mS/cm) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8
Feb-01	0.042	0.039	0.070	0.077			0.022	0.034
Mar-01	0.064	0.089	0.089	0.089	0.025	0.032	0.025	0.032
Apr-01	0.064	0.096	0.076	0.070	0.057	0.034	0.031	0.283
May-01	0.058	0.040	0.102	0.005	0.096	0.440	0.063	0.003
Jul-01	0.030	0.044	0.040	0.061	0.021	0.027	0.029	0.025
Aug-01	0.027	0.043	0.042	0.055	0.018	0.023	0.027	0.025
Sep-01	0.041	0.042	0.051	0.060	0.202	0.022	0.024	0.026
Oct-01	0.042	0.044	0.052	0.064	0.024	0.022	0.029	0.026
Nov-01	0.042	0.045	0.056	0.070	0.021	0.022	0.028	0.025
Dec-01	0.044	0.048	0.056	0.070	0.058	0.014	0.024	0.025
Jan-02	0.046	0.035	0.064	0.09	0.024	0.025	0.028	0.028
Feb-02	0.035	0.048	0.070	0.09	0.026	0.026	0.025	0.028
Mar-02	0.039	0.051	0.115	0.122	0.031	0.027	0.029	0.032
Apr-02	0.058	0.066	0.22	0.11	0.044	0.041	0.042	0.045

Table 13. Electrical conductivity (mS/cm) in the water samples of the Sharavathi upstream (cont...).

Months	Sampling sites
	9	10	11	12	13	14	15	16
Feb-01		0.023
Mar-01	0.03	0.025	0.032	0.032	0.032
Apr-01	0.03	0.044	0.44	0.096	0.32
May-01	0.12	0.045	0.064	0.037	0.12
Jul-01	0.023	0.02	0.025	0.026		0.06	0.067	0.029
Aug-01	0.022	0.02	0.025	0.026		0.028	0.054	0.027
Sep-01	0.026	0.02	0.026	0.023	0.020	0.038	0.064	0.049
Oct-01	0.249	0.02	0.025	0.023	0.021	0.063	0.061	0.059
Nov-01	0.024	0.021	0.024	0.031	0.022	0.077	0.077	0.059
Dec-01	0.023	0.028	0.026	0.024	0.023	0.077	0.09	0.058
Jan-02	0.029	0.033	0.03		0.016	0.083	0.09	0.064
Feb-02	0.038	0.032	0.031		0.028			0.064
Mar-02	0.039	0.037	0.035		0.043
Apr-02	0.062	0.053	0.048		0.067

In downstream regions, some localities were recorded with higher electrical conductivity. This is due to the salt-water intrusion by the Arabian Sea in these localities. Table 14 details the electrical conductivity of water samples from the downstream.

Table 14. Electrical conductivity (mS/cm) in the water samples of the Sharavathi downstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	0.04		0.05	0.04	0.05	0.04		0.05	0.05	0.05	0.05
Dec-02	0.04	0.06	0.04	0.04	0.04	0.04		0.05	0.05	0.05	0.05
Jan-03	0.05	0.06	0.05	0.06	0.05	0.07	0.05	0.06	0.06	2.35	0.05
Feb-03	0.06			0.08	0.04	0.08	0.04	0.08	0.08	4.35	0.06
Mar-03	0.05	0.07		0.08	0.05	0.08	0.04		0.09	2.84	0.06
April-03	0.06	0.08		0.07	0.05	0.08	0.04		0.08	3.56	0.05
May-03	0.06	0.12		0.09	0.05	0.08	0.05		0.16	4.41	0.05
Jun-03	0.04		0.05	0.05	0.06	0.06	0.06	0.07		0.16	0.06

Table 14. Electrical conductivity (mS/cm) in the water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	0.04	0.06	0.04	0.04	0.04	0.06	0.05			0.04	0.05	3.28
Dec-02	0.04	0.06	0.03	0.03	0.04					0.04	0.05	12.65
Jan-03	0.04	0.08	0.04	0.04	0.05	0.07		0.05		0.04	0.11	27.91
Feb-03	0.04	0.1	0.04	0.04	0.06	0.09		0.06	0.06		0.19	28.61
Mar-03	0.04	0.13	0.05		0.07	0.09		0.07	0.06		1.1	28.82
April-03	0.04	0.15	0.04		0.07	0.09		0.07	0.06		2.1	30.2
May-03	0.04	0.18	0.05		0.07			0.07	0.06		22.15	29.77
Jun-03	0.04	0.08	0.05		0.05			0.06	0.04		0.44	10.06

pH, Acidity and Alkalinity

In the upstream, pH ranged from 6.53 - 8.25 (Table 15). Acidity 2.5 –40 mg/L (Table 16) and alkalinity value ranged from 8 – 75 mg/L (Table 17), results well within the limits (NEERI and WHO standards).

Table15. pH in water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	7.4	6.9	7.3	7.5			7.5	6.53		6.7
Mar-01	6.85	6.53	6.78	7.2	6.85	6.8	6.9	7.4	6.9	6.94	6.75	6.55	6.65
Apr-01	7	7.2	7	7.4	6.72	6.94	6.94	6.94	6.55	7	7.4	7	6.72
May-01	7.4	6.9	7.74	7	6.94	6.55	6.72	6.59	6.75	7	7	7.4	6.94
Jul-01	7.09	6.89	6.97	6.98	6.95	7.22	6.94	6.65	6.6	6.93	6.8	6.99		7.01	6.98	6.85
Aug-01	6.98	7.03	7.15	7.05	7.24	7.07	7.21	7.06	6.69	6.99	6.85	7.03		7.03	6.94	6.83
Sep-01	7.3	7.12	7.17	7.03	7.01	6.64	7.01	7.13	6.75	6.53	6.88	7.27	6.88	7.02	7.53	7.07
Oct-01	7.5	7.43	7.85	7.58	7.12	6.9	7.21	7.38	7.33	7.34	7.33	7.45	7.02	7.9	7.7	7.83
Nov-01	7.35	7.25	7.26	7.55	7.19	7.01	7.27	7.1	7.06	6.99	7.03	6.56	6.96	7.2	7.5	7.34
Dec-01	7.4	7.71	7.59	7.86	6.98	7.76	7.36	7.26	7.01	7.45	7.46	7.43	7.45	7.55	7.81	7.28
Jan-02	7.25	7.2	7.1	7.38	7.08	7.09	7.07	7.01	7.9	7.05	6.69		7.03	7.25	7.48	7.18
Feb-02	7.62	7.7	8.25	7.75	7.7	7.47	7.13	7.38	7.36	7.01	6.93		7.04			7.25
Mar-02	7.27	7.25	7.01	7.73	7.45	7.45	7.58	7.62	7.48	7.38	7.32		7.25
Apr-02	7.41	8.41	7.05	7.15	6.54	6.55	6.77	7.02	7.76	6.52	6.57		6.63

Table 16. Acidity (mg/L) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	16	20		8			8	8		12
Mar-01	8	8	12	12	20	20	12	12	12	16	8	16	12
Apr-01	6	12	8	12	8	8	8	8	12	8	8	12	12
May-01	12	16	12	9	12	20	8	12	6	12	20	12	12
Jul-01	5	5	5	5	2.5	2.5	2.5	2.5	2.5	2.5	2.5	2.5		2.5	2.5	12
Aug-01	10	5	5	10	10	5	10	10	10	5	10	10		10	15	10
Sep-01	15	15	15	20	20	10	15	30	15	10	15	15	10	15	20	20
Oct-01	12	12	10	15	18	8	12	15	12	8	12	12	8	12	18	18
Nov-01	12	12	12	12	15	10	12	12	12	10	15	12	8	12	15	15
Dec-01	17.5	17.5	17.5	17.5	10	12.5	12.5	12.5	12.5	12.5	15	15	12.5	25	30	20
Jan-02	20	17.5	20	20	12.5	15	15	12.5	12.5	15	15		12.5	25	30	25
Feb-02	20	20	20	20	10	20	10	10	20	30	20		10			30
Mar-02	30	30	40	30	20	30	30	20	30	30	30		30
Apr-02	25	25	35	22	21	25	23	21	32	25	25		27

Table 17. Alkalinity (mg/L) in the water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	48	40	28	68			24	38		34
Mar-01	44	56	52	48	32	40	26	44	52	64	60	35	40
Apr-01	60	40	44	48	36	44	38	32	49	48	36	32	48
May-01	56	52	48	52	42	50	48	52	52	40	52	48	50
Jul-01	35	30	35	45	20	20	20	30	20	20	25	25		55	50	32
Aug-01	45	45	50	45	45	45	30	35	20	20	25	24		30	30	30
Sep-01	40	40	45	40	45	35	35	35	20	20	24	28	24	28	30	28
Oct-01	45	40	50	20	20	25	30	30	25	20	25	25	25	55	55	60
Nov-01	45	45	55	25	25	30	30	35	30	25	25	30	30	60	65	55
Dec-01	48	48	59	30	30	30	35	35	32	28	26	32	35	55	68	58
Jan-02	16	12	8	20	8	8	16	8	8	12	8		8	24	8	20
Feb-02	32	16	12	20	16	12	24	20	8	12	8		12			12
Mar-02	75	50	50	50	25	25	50	25	25	25	25		25
Apr-02	50	45	52	50	33	31	48	28	22	25	30		32

In the downstream, pH value was generally in circum neutral condition of 6.5 – 7.5 and rarely exceeded 8.0 (Vatahalla: 8.67 in May 2003). Apart from this individual observation, all other localities had pH level within the permissible level of NEERI (Table 18). Tables 19and 20 show corresponding alkalinity and acidity values of Sharavathi downstream. They were also observed within the permissible level of 100 – 250mg/L.

Table 18.  pH in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	7.26		7	6.98	6.84	6.75		7.14	7.13	6.97	7.01
Dec-02	7.13	7.4	6.72	6.93	7.01	6.98		7.04	7.05	6.95	6.99
Jan-03	7.25	7.59	7.22	7.1	6.94	7.36	6.94	7.31	7.52	7.42	7.35
Feb-03	7.11			6.76	6.78	7.19	6.99	6.91	7.74	7.68	6.93
Mar-03	7.35	7.26		6.36	6.61	6.62	6.9		7.07	7.23	6.37
April-03	7.1	7.28		6.55	6.67	6.76	6.92		6.88	7.17	6.58
May-03	7.29	7.05		6.71	6.68	6.66	6.83		6.92	7.18	6.44
Jun-03	6.66		6.8	6.62	6.51	6.79	6.88	7.13		6.71	7.07

Table 18.  pH in water samples of the Sharavathi downstream (cont...).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	7.5	7.63	7.05	6.94	7.21	7.54	7.27			6.74	6.68	7.07
Dec-02	7.07	7.52	7.06	7.01	7.13					6.78	6.81	7.46
Jan-03	7.07	7.84	6.9	7.23	7.3	7.8		7.3		6.98	7.27	7.38
Feb-03	7.22	7.88	7.21	7.12	7.3	7.6		7.3	6.5		7.16	7.61
Mar-03	6.84	7.85	6.56		7.5	7.4		6.9	6.7		6.84	7.54
April-03	7.16	7.72	6.96		7.2	7.6		7	6.6		6.61	7.51
May-03	7.08	8.67	6.89		7.17			6.84	6.81		6.53	7.54
Jun-03	7.3	7.49	7.5		7.33			6.55	6.68		6.21	7.18

Table 19. Alkalinity (mg/L) in the water samples of the Sharavathi downstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	13.93		16.87	13.2	16.87	16.87		19.8	15.4	19.07	21.27
Dec-02	15.4	24.2	17.6	15.4	16.13	16.5		19.07	18.7	19.8	19.8
Jan-03	15.4	26.4	15.4	19.8	13.2	22	11	17.6	24.2	26.4	17.6
Feb-03	21.6			31.2	16.8	28.8	14.4	26.4	33.6	38.4	21.6
Mar-03	21.6	36		28.8	19.2	31.2	14.4		40.8	45.6	21.6
April-03	24	38.4		28.8	21.6	33.6	19.2		38.4	45.6	19.2
May-03	24	40.8		36	19.2	26.4	16.8		74.4	48	19.2
Jun-03	14.4		14.4	16.8	19.2	16.8	19.2	9.6		19.2	21.6

Table 19. Alkalinity (mg/L) in the water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	13.2	24.2	12.1	15.4	13.2	22	17.6			13.2	14.67	25.7
Dec-02	15.4	30.8	11	13.2	14.3					13.93	17.6	46.2
Jan-03	13.2	28.6	11	11	17.6	28.6		17.6		11	30.8	73.7
Feb-03	16.8	45.6	14.4	14.4	21.6	38.4		24	24		33.6	76.8
Mar-03	16.8	60	19.2		33.6	40.8		26.4	24		26.4	79.2
April-03	16.8	67.2	16.8		28.8	45.6		28.8	26.4		24	72
May-03	16.8	74.4	19.2		26.4			24	21.6		43.2	74.4
Jun-03	19.2	26.4	19.2		16.8			12	12		9.6	28.8

Table 20. Acidity (mg/L) in the water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	1.8		2.1	2.7	1.8	1.8		1.8	1.8	2.4	3.6
Dec-02	2.7	2.7	2.7	2.25	2.7	2.7		3	1.8	2.4	2.7
Jan-03	1.8	1.8	1.8	1.8	1.8	1.8	1.8	0.9	3.6	1.8	0.9
Feb-03	1.8			5.4	1.8	1.8	1.8	5.4	3.6	3.6	3.6
Mar-03	3.6	3.6		5.4	3.6	3.6	3.6		5.4	3.6	3.6
April-03	4	6		2	2	4	2		2	4	2
May-03	4	4		6	4	8	4		8	6	6
Jun-03	4		2	4	4	4	4	4		4	4

Table 20. Acidity (mg/L) in the water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	1.8	2.7	1.8	1.8	2.7	2.7	1.8			1.8	2.7	2.7
Dec-02	2.7	2.7	2.7	2.4	2.25					2.7	4.5	1.8
Jan-03	1.8	1.8	1.8	2.7	1.8	1.8		1.8		1.8	1.8	2.7
Feb-03	3.6	5.4	3.6	1.8	1.8	1.8		3.6	3.6		3.6	3.6
Mar-03	3.6	5.4	3.6		3.6	3.6		3.6	3.6		3.6	9
April-03	2	4	2		2	4		4	4		2	4
May-03	4	0	6		4			4	6		12	6
Jun-03	4	4	2		4			4	2		4	8

Dissolved Oxygen

In the upstream region, dissolved oxygen ranged from 5 to 8.0 ppm (Table 21). This in the range of NEERI standards.

Table 21.  Dissolved oxygen (ppm) in water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	5	5.4	5.7	5.6			5.2	6		5.9
Mar-01	6	5.6	5.8	4.8	6.2	5	6.4	5.2	6.4	4.9	5.3	6	5.2
Apr-01	6.3	5	5.5	5.3	5.8	6	6.3	5.6	5.4	5.8	6.3	6	6.4
May-01	6.5	4.9	6	6	6.8	6.4	7	7	7	6	7	6.5	7
Jul-01	7.7	7.5	7.6	7.7	7.7	7.8	7.7	7.7	7.9	8	7.7	7.8		7.3	7.4	7
Aug-01	7.8	8	7.9	7.6	7.8	8	7.7	7.8	7.8	7.9	7.7	7.8		7.7	7.8	7
Sep-01	7.3	7	7.3	7.2	7.4	7.2	7	7.3	7	7.2	7.4	7.1	7.2	7.1	7.3	6.5
Oct-01	7.6	6.9	7.1	6.9	7.3	7.4	6.6	7.3	7	7	7.2	7	7.1	6.4	6.6	6.9
Nov-01	8	7.9	7.7	6.7	7.5	7.5	7.5	7.3	7.5	7.3	6.6	7.5	7	6.8	7.3	7.5
Dec-01	7.8	7.5	7.2	6.5	7.4	7.2	7.5	7	7.1	6.8	7	7.6	7.3	6.5	6.9	7.4
Jan-02	7.2	7.1	6.9	6.3	7	7	7.4	7.3	7.2	7	7.4		7.5	5.8	6.6	6.9
Feb-02	6.7	6.8	6.8	6.5	6.9	7	6.8	7	7.1	7.1	6.7		6.9			6.8
Mar-02	6.1	6.2	6.5	6.4	6.9	7.2	7.1	7.2	6.6	6.5	7.2		6.5
Apr-02	6	6.3	6.2	6.1	6.3	6.5	6.4	6.5	6.1	6.2	6.5		6.3

In downstream, DO at Chandavar [16.3 ppm], Gudankateholé [13 ppm], Dabbod [12.2 ppm], Hossagadde [12.2 ppm], Hennur [12.2 ppm] showed comparatively higher values due to high inflow and increased water turbulence in the region. Apart from these extremities, DO range was very much similar to upstream catchment (Table 22).

Table 22.  Dissolved oxygen (ppm) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02
Dec-02	8.1	7.3	12.2	12.2	11.4	12.2		9.7		7.3	6.5
Jan-03			6.5	5.2	6.2	5.9	6.8	8.6	7.9	7.5	6.9
Feb-03	6.3			4.1	6.1	4.5	6.9	5.1	7.7	5.3	6
Mar-03	6.2	6.8		4.2	6.4	5.8	6.9		6.6	6.7	5.5
April-03	6.8	7.1		4.6	5.6	6.7	6.9		6.6	5.9	5.5
May-03	7.4	6.6		4.7	6	6.8	7.1		6.2	6.1	4.9
Jun-03	7.2			6	6.6	6.4	6.7	6.7		6.5	6.6

Table 22.  Dissolved oxygen (ppm) in water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02
Dec-02	8.9	8.1	11.4		7.3					16.3	13	7.31
Jan-03	7.1	8	8.2	7.3	9.6	6.4		6.3		7.4	5.6
Feb-03	7.1	6.8	7.1	8.1	7.4	6.4		5.3	6.7		4
Mar-03	6.9	6.7	7.9	6.6	7.2	6.3		5.5	6.8		5.7
April-03	6.5	6.8	6.9		6.4	6.5		6.6	6.9		5.9
May-03	6.9	9.1	6.9		6.6			6.5	7		6.1
Jun-03	6.6	8.4	6.7		7.4			7.4	7.6		7.2

Chloride

The chloride concentration fluctuated from 4.9 to 63.9 mg/L in the upstream region, well within the limits of NEERI (Table 23).

Table 23.  Chloride concentration (mg/L) in water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	17.9	12.9	14.9	13.9			10.9	8.9		9.99
Mar-01	4.9	6.9	12	11	6.9	7.5	6.9	7.9	7.1	5	10.9	8.9	12
Apr-01	15	9.9	10.9	8.9	9.9	11	8.9	9.9	8.9	11.9	12.9	9.9	12
May-01	33	23	21.8	23	16	22	18	23	14	18.5	20.8	19.7	21.2
Jul-01	19.9	14.9	14.9	14.9	14.9	19.9	14.9	14.9	14.9	19.9	14.9	14.9		19.9	24.9	12.99
Aug-01	14.99	19.99	14.99	9.99	14.99	9.99	14.99	14.99	14.9	19.9	14.9	13.9		9.99	14.99	14.99
Sep-01	14.99	14.99	14.99	12.99	12.49	14.99	14.99	14.99	9.99	14.99	9.99	12.9	14.99	12.9	19.99	14.99
Oct-01	24.9	19.99	19.99	24.9	14.99	24.99	14.99	19.99	19.99	19.99	19.99	14.99	19.99	14.99	19.99	19.99
Nov-01	24.99	14.99	14.99	14.99	9.99	14.99	9.99	14.99	14.99	14.99	9.99	14.99	14.99	14.99	14.99	14.99
Dec-01	24.9	24.9	29.99	34.98	34.98	29.99	29.99	29.99	29.99	29.99	29.99	24.9	39.98	34.98	34.98	34.98
Jan-02	17.04	22.72	22.72	25.56	25.56	22.76	25.56	22.72	25.56	25.56	28.4		25.56	28.4	31.24	25.56
Feb-02	19.88	25.56	19.88	22.72	19.88	17.04	17.04	17.04	25.56	31.24	17.04		19.88			19.88
Mar-02	42.6	63.9	63.9	56.8	42.6	56.8	35.5	42.6	49.7	49.7	49.7		42.6
Apr-02	17.49	42.48	22.47	24.99	14.99	22.49	17.49	19.99	19.99	22.49	19.99		24.99

In Haddinabal, Gudankateholé and Badagani of downstream, Chloride concentration was comparatively higher (range: 3.19 – 13320.9 mg/L; Table 24) than other sites (both in upstream as well in downstream). Intrusion of salt-water in the above regions is the main reason for higher chloride concentration.

Table 24. Chloride concentration (mg/L) in Sharavathi downstream water samples.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	1.91		2.87	4.47	3.19	3.51		3.83	2.55	3.19	5.1
Dec-02	2.87	2.39	4.79	4.79	4.15	4.31		4.47	4.31	4.79	2.87
Jan-03	6	6	6	8	6	8	6	16	6	655.8	6
Feb-03	7			11	6	8	6.5	11	7	50.98	7
Mar-03	7	7		8	7	10	6		7	782.75	7
April-03	7	6		9	6	8	6		7	1017.68	7
May-03	7	6		9	6	11	7		31	3049.1	7
Jun-03	5		9	7	8	8	10	9		37.99	8

Table 24. Chloride concentration (mg/L) in Sharavathi downstream water samples (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	2.87	4.15	2.87	1.91	3.19	3.83	3.83			3.19	4.47	871
Dec-02	2.87	3.35	3.83	2.9	3.35					4.79	6.7	5344.1
Jan-03	4	6	6	6	6	6		8		6	16	12371.2
Feb-03	6	8	5	6	7	7		8	7
Mar-03	6	7	7		7	7		9	9
April-03	6	8	5		7	7		9	8		570.82	13320.9
May-03	6	9	6		8			10	8		364.89	523.8
Jun-03	5	34.99	5		7			9	6		130	3573.9

Sulphate

The sulphate concentration in the representative samples from the upstream catchment ranged from 0.34 to 32.02 mg/L, within the limits given by NEERI (Table 25).

Table 25.  Sulphate concentration (mg/L) in water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	19.42	16.05	20.12	32.02			15.28	17.2		16.4
Mar-01	14.22	16.22	14.89	25.77	13.17	23.35	18.62	14.89	24.81	14.89	20.5	18.29	16.65
Apr-01	11.3	22.32	24.52	14.65	6.99	12.5	7.15	20.11	14.5	11.87	10.05	10.05	13.79
May-01	13.27	9.52	15.23	9.24	10.04	15.23	12.4	9.32	12.51	7.39	10.93	12.4	14.21
Jul-01	4.96	11.28	9.47	22.1	7.44	2.93	4.51	11.28	10.15	7.44	7.66	6.76		21.2	20.07	24.36
Aug-01	13.26	10.38	6.34	15.86	0.86	0.86	0.86	7.86	8.99	6.34	6.53	5.86		19.86	29.9	32
Sep-01	4.76	11.9	9.52	14.86	2.3	4.28	3.33	2.38	3.8	3.33	4.76	3.33	4.76	17.86	15.7	4.76
Oct-01	1.76	4.47	1.76	11.94	1.49	1.19	2.38	2.69	6.86	1.79	1.19	1.49	1.79	9.25	22.3	3.88
Nov-01	7.46	8.06	8.65	9.55	8.06	8.06	9.55	8.36	8.65	10.15	9.85	10.44	11.64	12.53	14.92	13.13
Dec-01	10.46	9.69	11.59	12.56	7.58	9.25	10.25	11.25	12.58	13.01	9.89	11.49	12.59	17.58	18.59	16.48
Jan-02	5.07	1.33	4.53	8	5.87	2.67	2.67	2.13	7.2	22.66	9.33		4.27	7.466	12	13.66
Feb-02	2.99	2.45	4.89	4.89	0.54	3.53	5.17	4.35	2.18	8.16	9.25		5.44			9.25
Mar-02	2	4	9.33	5	0.34	0.67	0.34	0.67	0.67	3.33	0.67		0.67
Apr-02	2.51	3.24	8.99	6.21	1.24	1.25	1.65	1.22	1.54	2.13	2.01		0.99

In downstream, apart from Haddinabal, Gudankateholé and Badagani, all other sites had low sulphate concentration, but within NEERI’s specification (Table 26).

Table 26.  Sulphate concentration (mg/L) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	3.78		3.62	2.5	2.18	2.57		2.07	1.87	3.2	3.43
Dec-02	1.93	1.29	1.47	1.64	1.6	2.52		1.33	2.05	1.68	1.35
Jan-03	4.44	2.46	2.22	4.33	2.57	2.34	3.63	2.46	2.22	79.29	3.51
Feb-03	1.99			2.69	1.64	1.87	1.29	1.87	1.75	117.53	1.29
Mar-03	2.34	2.57		2.69	2.81	3.39	4.56		1.52	84.2	1.52
April-03	1.87	2.11		1.87	1.52	1.99	1.99		1.64	113.21	1.05
May-03	2.22	2.46		1.64	1.52	2.46	2.57		2.34	93.56	1.87
Jun-03	5.61		13.57	1.52	1.99	1.99	1.05	3.51		3.63	2.11

Table 26.  Sulphate concentration (mg/L) in the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	3.39	2.73	3.12	1.64	3.08	2.69	3.98			2.77	2.49	123.8
Dec-02	1.52	1.82	1.64	1.29	1.41					1.75	2.34	224.2
Jan-03	2.11	2.22	3.74	1.99	2.34	2.69		4.44		3.51	3.16	837.4
Feb-03	1.64	2.22	1.4	1.87	1.75	2.69		1.99	1.99		2.92
Mar-03	1.4	2.57	1.75		2.22	2.57		2.34	1.29		38.13	456.1
April-03	2.46	3.63	1.52		1.75	2.22		2.69	1.64		48.89	1765.9
May-03	2.11	3.98	1.64		2.11			3.39	2.57		1090.6	1754.3
Jun-03	1.4	3.51	1.4		1.75			5.15	8.07		12.16	321.6

Total Hardness

In the water samples of upstream, total hardness ranged from 27.25 to 148.29 mg/L (Table 27). Except four incidences from Sharamanavathi, Haridravathi, Keshawapura and Sampekai, where total hardness reached beyond 120mg/L, all other sites had very low hardness. The reason for higher concentration could not be substantiated.

Table 27.  Total Hardness (mg/L) in water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	59.95	27.25	49.05	27.25			30.12	30.35		32.7
Mar-01	54.4	49.05	81.7	76.3	49.05	43.6	49.5	76.3	54.5	49.5	38.15	40.9	54.5
Apr-01	43.6	43.3	39.24	52.32	37.5	49.7	43.6	30.52	50.7	43.6	48.8	39.24	34.48
May-01	52	43.6	56.6	56.6	50.2	54.3	60.9	65.4	58.2	56.6	58.9	58.2	54.3
Jul-01	59.5	59.9	76.3	82.2	82.3	49.5	40.9	38.15	54.5	49.5	49.05	43.6		54.5	54.5	40.6
Aug-01	39.24	39.24	43.6	43.6	47.96	34.88	30.52	30.52	46.32	46.35	45.63	40.56		56.68	78.48	39.24
Sep-01	61.04	43.6	56.68	56.6	43.6	52.32	30.52	61.04	39.24	47.96	69.76	78.48	47.9	78.89	122.08	78.48
Oct-01	65.4	49.05	49.05	54.5	43.6	54.5	49.05	49.05	59.95	59.95	43.6	59.95	49.05	70.85	59.95	59.95
Nov-01	78.48	52.32	143.88	122.08	78.48	52.32	87.2	61.04	43.6	39.24	47.96	52.32	56.68	148.24	82.84	65.4
Dec-01	43.6	39.24	47.96	52.32	43.6	30.52	30.52	56.68	65.4	52.32	61.04	43.6	65.4	126.44	95.92	47.96
Jan-02	28	36	68	80	40	32	32	36	32	28	28		32	76	76	44
Feb-02	60	32	52	88	40	20	32	36	44	22	92		32			64
Mar-02	60	50	50	60	50	50	30	30	70	40	30		40
Apr-02	58	42	55	55	48	50	35	38	68	54	28		38

Similar to upstream, generally all the sites in downstream exhibited low hardness concentration (Table 28). The reason for higher concentration in Haddinabal, Gudankateholé and Badagani could be due to salt-water intrusion in these regions.

Table 28.  Total Hardness (mg/L) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	16		19.33	14.67	17.33	16.67		18	17.33	21.33	22
Dec-02	17	23	17	15	18.67	19		20	19	18.67	20
Jan-03	16	24	16	20	16	24	12	24	24	232	18
Feb-03	18			24	12	22	12	20	26	400	18
Mar-03	14	24		24	14	20	10		32	272	14
April-03	18	26		24	14	22	10		28	336	14
May-03	18	28		28	12	18	12		64	400	6
Jun-03	12		14	14	18	16	16	20		28	20

Table 28.  Total Hardness (mg/L) in water samples of the Sharavathi downstream (cont…)

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	14	22	16.67	16	16	22	16			14	14.67	1676.7
Dec-02	12	23	16	13.33	16					12.67	18	1866.7
Jan-03	12	26	12	12	22	32		16		16	32
Feb-03	12	34	10	10	16	30		18	16		32	3800
Mar-03	10	44	10		26	32		16	18		116	4100
April-03	10	52	10		36	36		20	16		196	4300
May-03	6	52	6		8			6	10		3050	4200
Jun-03	12	22	14		16			16	12		52	1250

Calcium Hardness

In downstream sites, Calcium hardness ranged between 4 – 38 mg/L (excluding Haddinabal, Gudankateholé and Badagani). Table 29 details the Calcium hardness in Sharavathi downstream.

Table 29.  Calcium hardness (mg/L) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	8		8	8	8	8		8	8.67	9.33	10
Dec-02	8	12	8	8	8	8		10	10	10	9
Jan-03	8	12	8	12	8	12	6	12	12	48	8
Feb-03	10			14	6	14	6	10	14	100	8
Mar-03	8	16		14	8	12	6		18	58	10
April-03	10	18		14	10	12	8		16	68	8
May-03	10	18		16	8	12	6		38	100	8
Jun-03	8		8	8	10	8	8	12		12	10

Table 29.  Calcium hardness (mg/L) in water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	8	11.33	8	6	7.33	12	8			6	7.33	66.7
Dec-02	8	12	6	6.67	8					6.67	8	366.7
Jan-03	6	16	6	4	8	14		10		8	14
Feb-03	6	24	6	6	10	16		10	10		16	600
Mar-03	6	36	6		18	18		10	10		36	700
April-03	8	42	8		20	18		8	10		56	700
May-03	8	50	8		10			8	12		500	700
Jun-03	8	16	10		8			10	8		16	200

Magnesium Hardness

In downstream, magnesium hardness was within the permissible level (30 mg/L) in almost all sites (except sampling site 10, 22 and 23). Table 30 shows the magnesium hardness recorded from the downstream localities.

Table 30. Magnesium hardness (mg/L) in water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	8		11.33	6.67	9.33	8.67		10	8.67	12	12
Dec-02	9	11	9	7	10.67	11		10	9	8.67	11
Jan-03	8	12	8	8	8	12	6	12	12	184	10
Feb-03	8			10	6	8	6	10	12	300	10
Mar-03	6	8		10	6	8	4		14	214	4
April-03	8	8		10	4	10	2		12	268	6
May-03	8	10		12	4	6	6		26	300
Jun-03	4		6	6	8	8	8	8		16	10

Table 30. Magnesium hardness (mg/L) in water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	6	10.67	8.67	10	8.67	10	8			8	7.33	1610
Dec-02	4	11	10	6.67	8					6	10	1500
Jan-03	6	10	6	8	14	18		6		8	18
Feb-03	6	10	4	4	6	14		8	6		16	3200
Mar-03	4	8	4		8	14		6	8		80	3400
April-03	2	10	2		16	18		12	6		140	3600
May-03											2550	3500
Jun-03	4	6	4		8			6	4		36	1050

Sodium and Potassium

Sodium concentration in upstream sites fluctuated between 2.1 to 101.4 mg/L (Table 31) and potassium values ranged between trace amounts to 9.5 mg/L (Table 41). The observed values are well within the limits given by NEERI. Concentration of potassium was much less compared to sodium, as it is not very abundant in natural waters.

Table 31.  Sodium concentration (mg/L) in water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	16.05	11.74	16.4	16.4			14.28	15.25		17.21
Mar-01	7.81	9.99	10.44	15.57	12.53	9.8	11.4	12.3	11.5	12.34	12.64	12.97	13.5
Apr-01	18	18	17	17.4	17.21	14.28	15.25	16.5	13.9	19	32.02	21	16.4
May-01	12.52	12.64	12.25	11.4	12.3	17.5	15.75	11.5	12.4	9.99	10.53	10.44	7.3
Jul-01	8.31	13.77	11.33	17.66	4.43	5.63	5.92	5.82	5.24	4.46	5.71	6.04		18.46	29.22	9.23
Aug-01	6.9	11.73	9.27	9.49	2.1	2.61	2.67	2.80	2.53	4.12	5.10	4.03		9.82	9.41	8.24
Sep-01	10.58	12.6	14.07	10.49	3.68	4.22	4.34	4.28	4.38	3.53	4.68	4.7	3.53	10.25	24.5	14.24
Oct-01	9.86	12.36	13.95	15.28	4.15	5.2	4.99	5.69	4.56	4.28	5.1	4.86	4.12	15.6	28.8	20.1
Nov-01	8.63	11.64	14.5	38.08	4.73	5.19	5.73	6.13	5.5	4.61	6.14	6.32	4.64	39.04	40.04	28.04
Dec-01	8.95	10.76	10.54	65.4	4.58	5.15	5.10	5.59	4.96	5.50	5.56	5.48	4.79	85	101.4	34.5
Jan-02	11.23	10.8	15.99	55.36	5.47	6.04	6.46	6.52	5.82	6.68	6.49		5.81	85.27	89.64	35.01
Feb-02	13.33	16.78	12.30	43.54	6.53	7.10	7.31	2.3	9.13	8.53	4		8.07			30.49
Mar-02	9.20	4.36	4.00	49.25	6.68	9.49	9.30	9.39	9.59	8.52	8.91		9.29
Apr-02	10.21	5.321	3.68	47.86	5.69	10.25	10.25	9.37	9.46	8.65	8.64		10.25

Table 32.  Potassium concentration (mg/L) in water samples of the Sharavathi upstream

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	0.4	0.8	0.7	0.8			ND	ND		ND
Mar-01	0.039	0.039	0.156	ND	ND	ND	ND	0.078	0.039	ND	0.039	ND	0.039
Apr-01	0.08	1.4	1.2	0.84	0.43	0.67	0.34	0.43	0.34	1.4	0.91	1.2	0.67
May-01	0.039	0.56	1.4	0.91	0.22	1.4	0.43	0.1	1.2	1.2	0.84	0.91	0.34
Jul-01	1.134	2.151	1.564	2.151	0.195	0.743	0.86	0.743	0.391	0.235	0.704	0.899		1.447	2.503	0.169
Aug-01	0.116	0.232	0.116	0.232	ND	0.116	0.116	1.96	0.291	0.203	0.502	0.775		0.155	0.193	0.193
Sep-01	0.01	0.01	0.01	0.02	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.01	0.013	0.03	0.04	0.01
Oct-01	0.95	0.98	0.88	1.1	0.099	0.098	0.15	0.2	0.298	0.258	0.35	0.42	0.199	0.56	0.33	0.99
Nov-01	1.076	1.35	1.35	1.55	0.3	0.478	0.59	0.59	0.478	0.3	0.59	0.59	0.398	1.435	1.91	1.395
Dec-01	0.3	0.348	0.503	0.465	0.077	0.116	0.116	0.15	0.116	0.116	0.15	0.15	0.077	0.54	0.69	0.348
Jan-02	2.7	2.156	4.156	4.274	0.919	1.216	2.039	1.647	1.176	1.294	1.686		0.941	2.94	4.039	3.25
Feb-02	0.883	0.803	1.225	3.214	0.281	0.361	0.401	0.401	0.321	0.562	0.321		1.285			4.416
Mar-02	3.518	2.345	7.818	9.508	5.863	1.564	4.691	1.173	0.782	0.782	0.782		1.564
Apr-02	1.025	1.365	4.256	8.25	4.35	2.317	3.214	2.154	1.255	1.256	2.351		2.155

In downstream localities, the lowest concentration of 0.1 mg/L of sodium was recorded at Dabbe falls and Joginamutt and was highest with 36.60 mg/L at Chandubanu (Table 33). High sodium concentrations were attributed to seawater intrusion. The permissible range of sodium concentration for surface water is <1 - > 300 mg/L. Similarly, potassium concentration in the downstream sub-basins ranged between 0.09 – 6.4mg/L (0.7 – 1.80 mg/L [DS 4], 0.09– 2.50 mg/L [DS 3], 0.09 – 6.4 mg/L [DS 2], 0.46 – 2.6 mg/L [DS 5]).

Table 33. Sodium concentration (mg/L) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	5.46		6.57	6.53	6.38	6.52		7.08	6.73	6.92	6.98
Dec-02
Jan-03
Feb-03	17.79			17.59	17.88	15.75	17.88	5.73	17.5		17.3
Mar-03	17.88	16.52			17.69	11.86	17.79		17.4		17.3
April-03	17.59	17.01		16.33	17.3	14	17.88		17.3		17.5
May-03				5.03	3	11.9	3.8		36.6	5356.8	3.87
Jun-03	0.1		0.6	0.7	0.8	0.7	2.29	1.6		20.54	1.1

Table 33. Sodium concentration (mg/L) in water samples of the Sharavathi downstream (cont…)..

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	5.8	7.38	6.07	5.57	6.19	6.38	6.95			7.16	8.53	1339.8
Dec-02										7.16		1339.8
Jan-03												1339.8
Feb-03	17.69	10.11	17.69	17.79	17.5	17.2		14.29	17.3		53.36
Mar-03	17.79	6.12	17.59		16.72	17.2		12.44	15.75
April-03	17.79	3.6	17.88		16.33	16.62		7.78	15.84
May-03	2.42	13.6	2.5		4.5			12.08	4.06
Jun-03	0.02	2.19	0.4		0.8			1.2	0.1		70.58	1908

Table 34. Potassium concentration (mg/L) in water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	0.51		0.07	0.24	0.13	0.44		0.31	0.33	0.24	0.4
Dec-02
Jan-03
Feb-03	1.8			1	0.9	1.5	0.9	2.2	1		0.7
Mar-03	0.9	0.7			0.9	1.6	0.8		1		0.9
April-03	1	1.3		1.2	1.3	2.5	0.8		1.2		0.9
May-03				0.09	0.09	0.09	0.09		0.09	0	0.09
Jun-03	1.29			0.89	1.09	0.8	0.89	1.49		1.89	0.89

Table 34. Potassium concentration (mg/L) in water samples of the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	0.4	0.84	0.81	0.79	0.31	0.46	0.4			0.04	0.22	186.9
Dec-02										0.04		186.9
Jan-03												186.9
Feb-03	1.1	4.5	0.8	0.8	1	2.2		1.7	2.3		4.7
Mar-03	0.9	5.8	1.2		1.3	2.6		2	1.7
April-03	0.9	6.4	1		1.3	2.6		2.4	1.7
May-03	0.09	1.74	0.09
Jun-03	0.6	2.09	0.6		0.8			1.79	1.69		3.18	82

Nitrate Nitrogen

In Sharavathi upstream, Nitrate nitrogen concentration in water samples ranged from trace to 1.622 mg/L (Table 35).

Table 35. Nitrate concentration (mg/L) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	0.161	0.167	0.12	0.154			0.147	0.141		0.134
Mar-01	0.004	0.024	0.007	0.014	0.012	0.01	ND	ND	0.024	0.028	ND	ND	0.012
Apr-01	0.013	0.073	0.213	0.34	0.01	0.04	0.06	0.006	0.067	0.033	0.053	0.06	0.006
May-01	0.1	0.14	0.02	0.42	0.012	0.01	ND	0.14	0.024	0.16	0.13	0.4	0.14
Jul-01	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND	ND		ND	ND	0.099
Aug-01	0.015	0.05	0.01	0.01	0.015	0.075	0.01	0.095	0.1	0.015	0.075	0.074		0.11	0.12	0.095
Sep-01	0.045	0.075	0.15	0.15	0.022	0.15	0.12	0.15	0.15	0.03	0.105	0.095	0.095	0.14	0.157	0.105
Oct-01	0.052	0.079	0.155	0.168	0.066	0.099	0.085	0.13	0.056	0.098	0.256	0.099	0.101	0.169	0.561	0.589
Nov-01	0.055	0.086	0.162	0.199	0.092	0.087	0.098	0.092	0.105	0.159	0.361	0.134	0.198	0.235	0.942	0.789
Dec-01	0.061	0.101	0.188	0.254	0.15	0.025	0.056	0.075	0.213	0.312	0.587	0.857	0.534	0.654	1.023	0.954
Jan-02	0.083	0.139	0.251	0.307	0.279	ND	ND	0.008	0.335	0.587	0.979	0.712	0.979	0.979	1.259	1.623
Feb-02	0.042	0.063	0.021	ND	ND	ND	0.056	ND	ND	0.416	0.071		ND			ND
Mar-02	0.09	0.128	0.308	0.142	0.160	0.038	0.257	0.039	0.071	0.192	0.769		0.026
Apr-02	0.076	0.099	0.125	0.125	0.099	0.036	0.354	0.047	0.075	0.231	0.564		0.055

In downstream sites, nitrate concentration was higher at Hossagadde, Bhaskere and Mavinaholé with 1.011 mg/L, 1.208 mg/L and 1.114 mg/l respectively (Table 36). Comparatively, downstream sites had low nitrate concentration than upstream sites.

Table 36. Nitrate concentration (mg/L) in the water samples of the Sharavathi downstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	0.149		0.203	0.146	0.134	0.173		0.094	0.113	0.153	0.097
Dec-02	0.144	0.146	0.12	0.178	0.15	0.142		0.153	0.165	0.12	0.142
Jan-03	0.231	0.231	0.206	0.343	0.253	0.793	0.326	0.253	0.279	0.206	0.214
Feb-03	0.317			0.308	0.214	0.27	0.24	0.249	0.219	0.206	0.236
Mar-03	0.27	0.279		0.176	0.21	0.227	0.244		0.223	0.249	0.219
April-03	0.047	0.099		0.06	0.064	0.06	0.051		0.039	0.06	0.021
May-03
Jun-03	0.63		1.011	0.716	0.908	0.951	0.176	1.208		0.788	1.114

Table 36. Nitrate concentration (mg/L) in the Sharavathi downstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	0.103	0.103	0.21	0.2	0.13	0.1				0.12	0.32	0.13
Dec-02	0.13	0.12	0.17	0.183	0.155					0.13	0.18	0.11
Jan-03	0.27	0.3	0.39	0.43	0.24	0.26		0.3		0.21	0.29	0.25
Feb-03	0.29	0.21	0.27	0.21	0.27	0.24		0.27	0.28		0.24	0.19
Mar-03	0.2	0.2	0.19		0.24	0.21		0.23	0.24		0.27	0.19
April-03	0.05	0.04	0.12		0.13	0.09		0.09	0.06		0.14	0.04
May-03
Jun-03	0.154	0.24	0.206		0.163			0.514	0.65		0.48	0.18

Phosphate

The values ranged from non-detectable (ND) to 0.0929 mg/L (Table 37). The occasional rise in concentration can be attributed to the agricultural runoff getting into that water.

Table 37.  Phosphate concentration (mg/L) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Feb-01	0.007	0.009	0.009	0.008			0.006	0.018		0.007
Mar-01	0.008	ND	0.012	0.009	0.004	ND	0.002	ND	ND	0.005	ND	0.012	0.004
Apr-01	0.004	0.01	ND	0.004	0.004	ND	0.002	0.005	0.002	0.003	0.003	0.001	ND
May-01	0.002	0.003	0.001	0.01	ND	0.004	0.004	0.004	0.002	ND	0.004	0.014	ND
Jul-01	0.014	0.014	0.014	0.02	0.005	0.01	0.011	0.019	0.01	0.015	0.01	0.02		0.018	0.032	0.003
Aug-01	0.017	0.008	0.012	0.018	0.012	0.009	0.02	0.005	0.012	0.015	0.010	0.02		0.013	0.017	0.002
Sep-01	0.004	0.007	0.004	0.005	0.003	0.002	0.01	0.001	0.004	0.007	0.005	0.01	0.005	0.005	0.005	0.004
Oct-01	0.022	0.015	0.053	0.012	0.025	0.008	0.008	0.032	0.008	0.028	0.023	0.011	0.007	0.092	0.003	0.036
Nov-01	0.009	0.005	0.008	0.007	0.012	0.011	0.014	0.008	0.016	0.014	0.010	0.01	0.011	0.014	0.013	0.014
Dec-01	0.014	0.010	0.017	0.005	0.004	0.003	0.014	0.038	0.022	0.07	0.014	0.017	0.007	0.048	0.051	0.021
Jan-02	0.001	0.005	ND	0.009	0.008	0.003	0.007	0.004	0.003	0.004	ND		ND	0.004	0.001	0.002
Feb-02	ND	0.046	ND	0.057	ND	ND	0.009	ND	ND	ND	ND		ND			ND
Mar-02	0.003	0.002	0.006	0.018	0.006	0.017	0.017	0.014	0.005	0.001	0.004		0.001
Apr-02	0.002	0.002	0.004	0.026	0.005	0.021	0.015	0.015	0.005	0.002	0.004		0.002

Contrasting to upstream, the downstream localities generally had low phosphate concentration (trace to 0.025 mg/L) and fluctuations were also very less (Table 38).

Table 38.  Phosphate concentration (mg/L) in the water samples of the Sharavathi upstream.

Months	Sampling sites
	1	2	3	4	5	6	7	8	9	10	11
Nov-02	0.01		0.01	0.01	0.01	0.02		0.01	0.01	0.01	0.01
Dec-02	0.01	0.01	0.01	0.01	0.01	0.01		0.01	0.01	0.01	0.01
Jan-03	0.017	0.014	0.016	0.016	0.016	0.016	0.015	0.015	0.017	0.014	0.016
Feb-03	0.016			0.014	0.013	0.012	0.014	0.012	0.016	0.009	0.014
Mar-03	0.017	0.02		0.025	0.015	0.018	0.022		0.017	0.016	0.015
April-03	0.003	0.004		0.003	0.003	0.006	0.003		0.003	0.003	0.003
May-03	0.004	0.004		0.003	0.003	0.006	0.003		0.003	0.003	0.003
Jun-03	0.014		0.016	0.013	0.015	0.015	0.016	0.012		0.014	0.014

Table 38.  Phosphate concentration (mg/L) in the Sharavathi upstream (cont…).

Months	Sampling sites
	12	13	14	15	16	17	18	19	20	21	22	23
Nov-02	0.01	0.01	0.01	0.01	0.01	0.01	0.01			0.01	0.01	0.01
Dec-02	0.01	0.01	0.01	0.01	0.01					0.01	0.01	0.01
Jan-03	0.016	0.017	0.015	0.012	0.016	0.016		0.016		0.01	0.02	0.01
Feb-03	0.014	0.018	0.013	0.013	0.013	0.021		0.014	0.014		0.013	0.01
Mar-03	0.01	0.02	0.03		0.01	0.02		0.02	0.02		0.02	0.01
April-03	0.003	0.003	0.003		0.003	0.004		0.003	0.003		0	0
May-03	0.003	0.003	0.003		0.003			0.004	0.003		0.003	0
Jun-03	0.009	0.013	0.01		0.014			0.012	0.015		0.013	0.013

Iron
Iron concentration in all upstream sampling points was <0.3 mg/L, within the limits of NEERI and APHA (drinking water 0.3mg/L and freshwater bodies 1.0mg/L).

Ammonia
In upstream sites, concentration of ammonia ranged between <0.2 to 3 mg/L.

Fluoride
In downstream, fluoride concentrations in all sub-basins were 0.6 mg/L which falls within the standard limit of 0.6 – 1.2 mg/l for drinking water.

Coliform Bacteria
In upstream, water samples taken during monsoon had coliform bacteria at Sharavathi 1 and 2, Sharmanavathi, Haridravathi and its nearby streams (Keshawapura and Nandiholé). This is due to human or animal interference with the water bodies of the region. Other sampling sites showed occasional presence of coliform bacteria.

In downstream localities, coliform bacteria were found in almost all the samples. This could be due to human faecal matter or due to aquatic or terrestrial animal wastes. As per the permissible limits for drinking water, there should not be any coliform bacteria in the water.

Comparison with NEERI and WHO Standards

Table 39 details the comparison of the study with NEERI and WHO standards. Only those parameters having permissible levels according to NEERI are considered here. A few parameters have exceeded the stipulated limits, but they require continued monitoring.

Table 39. Obtained values vs. standard values of NEERI and WHO

Variables	Permissible Limits	Upstream	Downstream
Turbidity (NTU)	Not more than 10	<5 – 125	10 – 100
Total Dissolved Solids (mg/L)	100	13.77 – 110	16.2 – 15,090 mg/L
Colour	Colourless	Colourless – Brownish green	Colourless – Brownish green
pH	6.5-8.5	6.52-8.41	6.21-8.67
Conductivity (mS/cm)	0.05-1.5	0.003-0.44	0.03-30.20
Alkalinity (mg/L)	200	8 -75	9.6-79.2
Dissolved oxygen (ppm)	Not less than 3.0	4.8-8	4.0-16.3
Total Hardness (mg/L)	300	27.25 - 148.29	6-4300
Sulphate (mg/L)	150	0.34-32.02	1.05-1765.3
Chloride (mg/L)	250	4.9-63.9	1.91-13320.9
Sodium (mg/L)	200	2.1 - 101.4	0.1-1908
Potassium (mg/L)	-	Trace - 9.508	0.09-186.9
Nitrates (mg/L)	45	Trace - 1.623	0.021-1.114
Phosphates (mg/L)	0.03	Trace - 0.092	Trace – 0.025
Coliform Bacteria	Should be nil	Nil - Present	Nil – Present

Comparison between Sampling Sites in Upstream

The upper catchment area was divided in to three categories based on their disturbance level. Group A was classified under most disturbed area (agricultural activities, siltation process etc), whereas Group B and Group C come under comparatively less disturbed area. Table 40 gives the classification of groups based on their disturbance level.

Table 40. Classification of study area (upstream)

Group A	Group B	Group C
Sharavathi [1] and [2] Sharmanavathi [3] Haridravathi [4] Nandiholé [14] Keshavapura [15] Sampekai [16]	Muppane [5] Talakalale dam [6] Dam outlet [7]	Linganamakki Reservoir [8] Valagere [9] Yenneholé [10] Hurliholé [11] Nittur [12] Madenur [13]

Table 41 gives the comparison of water quality variables between sampling sites under each group.

Table 41. Comparison between sampling sites

Variables	Group A	Group B	Group C
Transparency (cm)	3 – 124	20 – 284	24 - 284
Turbidity (NTU)	10 – 125	<5 – 12	5 - 20
Colour	Light Brown - Brownish green	Colourless - Brownish green	Colourless - Brownish
Total Dissolved Solids (mg/L)	18.16 – 84	13.77 - 27.3	14.25 - 40.72
Total Suspended Solids (mg/L)	21.3 – 110	26 – 75	26 - 85
PH	6.53 - 8.25	6.54 - 7.757	6.53 - 7.76
Ammonia (mg/L)	<0.2 - >3.0	<0.2 – 3.0	<0.2 - 3.O
Total Hardness (mg/L)	27.25 - 143.88	20 – 87.2	22 - 78.48
Sulphate (mg/L)	1.76 - 32.02	0.34 – 23.35	0.67 - 17.2
Nitrates (mg/L)	ND - 1.6229	ND - 0.279	ND - 0.979
Phosphate (mg/L)	ND - 0.0929	ND - 0.0174	ND - 0.0699
Coliform Bacteria	Almost Present in all sampling sites	ND- Slightly Present	ND-Slightly Present

The results show that the physico-chemical and biological variables under group A is comparatively polluted than group B and group C in terms of transparency, turbidity, suspended solids, phosphate and coliform bacteria.

The tributaries flowing through the sub-basins Nandiholé (US1), Haridravathi (US2), Sharavathi (US4), Mavinaholé (US3) and Hilkunji (US8) (Group A) are relatively more polluted  (in terms of transparency, turbidity, suspended solids, phosphates and coliform) than the tributaries in the sub-basins Yenneholé (US5), Linganamakki (US9), and Hurliholé (US6) (Group B and C) in the Sharavathi upper catchment. The reason for higher pollution in the above said sub-basins is due to the agricultural and other anthropogenic activity in the catchment area. Secondly, the less water flow during lean seasons leads to increased concentration of pollutants in these regions.

Comparison between Sampling Sites in Downstream

Stagnant waters especially at Dabbod, Gudankateholé show low DO values in comparison to flowing waters of Vatahalla, Chandubanu. Drastic changes were observed in the water quality during the months of January, February, March and April in the Haddinabal stream due to seawater intrusion as evident by high conductivity and total dissolved solids with corresponding increase in values for all other parameters. Generally the water is saline only upto Badagani. The seawater intruded backwards upto Hablikapu nearly one and a half km away from Gudankateholé passing through 4 dams/obstructions. Farmers in the nearby areas have noticed crop damage i.e. stunted growth due to saline water usage.

Badagani showed high salinity during all months. Gudankateholé showed fresh water characteristics during November, December, and January. But during the months February, March and April the water turned saline. This has led to the contamination of nearby wells and rendered them unfit for drinking.

Turbidity levels at Dabbod a stream located at the southern end of Sharavathi downstream catchment exceeded the limits during the months of January and April. The reason for this abnormality can be attributed to the damming of this stream for agricultural purposes. Alkalinity levels have also shown substantial increase in the values similar to TDS values. All streams except Chandavar started flowing in the month June due to rains. There are natural variations and trends in the water quality that the water bodies are usually bound to experience over a period of time or season. Apart from Haddinabal, Gudankateholé and Badagani, all other sites had the water parameters within the stipulated range of Indian standards for drinking and agriculture except for turbidity and coliform bacteria.