1. ANCHEPALYA KERE

Table 1 Water quality of Anchepalya Lake with BIS standards

Chemical variables of Anchepalya Lake has been listed in Table 1. An alkaline range of pH was recorded at both inlet and outlet sampling site. The ionic concentration at both sites ranged from 9210-9220 μS/cm exceeding BIS limits. A high amount of organic matter was reflected through BOD and COD values (range, 48.80-55.40 ppm and 160.67-182 ppm respectively). Hardness accounted for industrial while chlorides concentration reflected untreated domestic inflow into the lake bed.

CURRENT THREATS (Refer Figure 1 and Plate 1)

1. Industrial waste and untreated sewage inflow from nearby Industries and household in Peenya,
2. Macrophyte cover (Eichornia sp.)
3. Dumping of construction waste, solid waste, etc.
4. Lake bed has been occupied for construction, Encroachment (filling of lake bed with construction waste).
5. No shoreline
6. Sludge deposition, Eutrophication.
   

PLATE 1

 

 

2. BEGUR DODDA LAKE

Table 2 water quality of Begur Lake with BIS standards

Chemical variables of Begur Lake has been listed in Table 2. pH ranged between 8.12-8.5. Water ionic concentration and dissolved solids were well within the BIS limits ranging from 706-722 μS/cm and 563-572 ppm respectively. BOD and COD of lake showed presence of less/ moderate amount of organic matter. Dumping of plastic and household waste was observed near sampling site 2 which led to blockage of water (Plate 2). Hardness was high at accounting for local human disturbances such as washing clothes and bathing. Chlorides and alkalinity was found to be less than 300 and 500 mg/L which also showed lake water is less/moderately polluted.

CURRENT THREATS (Refer Figure 2 and Plate 2)

1. Dumping of household waste.
2. Local disturbances (Washing clothes and open defecation)

3. BELANDUR LAKE

WATER QUALITY

Table 3 Water quality of Belandur Lake and BIS standards mentioned.

Water chemistry variables of Belandur Lake inlet and outlet have been listed in Table 3. pH was recorded as slightly acidic to neutral condition ranging from 6.89-7.67 because of industrial acidic waste inflow at inlet of lake. Ionic concentration, total dissolved solids, Chlorides and alkalinity were higher than the BIS standards for surface water (Table 3) which could also harm aquatic insects and algal growth. Fish species has been decreased due to increased macrophyte cover and thus decreased dissolved oxygen (range 2.64-3.68). Phosphate concentration ranged from 1.55-1.96 which has also led to increase in Eutrophication in lake. 

CURRENT THREATS (Refer Figure 3 and Plate 3)

1. Macrophyte cover (Eichornia sp.)
2. Dumping of construction waste, solid waste. Lake bed has been occupied for construction, Encroachment (filling of lake bed with construction waste)
3. Untreated sewage inflow
4. No shoreline
5. Sludge deposition
   
   PLATE 3

4. BOMMASANDRA LAKE

WATER QUALITY

Table 4 Water quality variables of Bommasnadra Lake with BIS standards mentioned.

Water quality of Bommasandra Lake has been listed in Table 4. Water quality status reflected contamination of water with sewage and nearby industrial untreated waste. Lake water showed high amount ions along with calcium (range, 140-146 mg/L) and chlorides (range, 205-234 mg/L) concentration. Alkalinity of water exceeds BIS limit ranged 624.75-640 mg/L which could also imbalance the aquatic life. Lake is covered with Eichornia sp. and hence oxygen level has been decreased to 1.24 mg/L at Inlet of lake. Fish kill was observed during later 2011 due to decreased oxygen and increased amount of ionic concentration. Piggery waste and household waste is observed near inflow region which has led to foul smell, green color of water (increased algal bloom) and has also blocked a portion of water body.

CURRENT THREATS (Refer Figure 4 and Plate 4)

1. Dumping of construction waste, solid waste, etc.
2. Local disturbances (Open defecation).
3. Decrease in water depth due to Sludge deposition.
4. Piggery waste and household waste and Fishing.
   
   PLATE 4

5. DODDABIDAREKALLU LAKE

WATER QUALITY

Table 5 Water quality of Doddabidarekallu Lake with BIS standard limits

Due to the macrophyte cover on Doddabidarekallu Lake sampling of water was difficult. The sampled collected and analysed at inflow has been listed in Table 5. All the chemical variables exceeding the required BIS values. Ionic concentration and dissolved solids showed the amount of pollution in water. BOD and COD concentration showed high organic matter in the lake. No fish is found due to decrease in water oxygen level. The black colored water observed at the inflow along with local human disturbances such as open defecation which has also led to contamination of water. This lake receives major industrial effluents from Peenya industrial area and domestic waste from surrounding village. Construction waste has been occupied at one side of lake bed.

CURRENT THREATS (Refer Figure 5 and Plate 5)

1. Dumping of construction waste and solid waste
2. Local disturbances
3. Sludge deposition
4. Completely covered with Macrophyte.
5. Untreated sewage and industrial inflow into the lake bed

   PLATE 5
   

   

   6. DODDANEKKUNDI LAKE

   NAME OF THE LAKE	DODDANEKKUNDI KERE
   GEOGRAPHIC DETAILS 12°58'29"N   77°41'16"E
   AREA (2002/2010)	42.01/38.66 ha
   ORGANIZATION	BBMP
   WARD / VILLAGE NAME	85- Doddanekkundi
   STATUS	Polluted
   RESTORATION	NO
   WATER CONDITION	Eutrophication, Green color, rotten smell

   

   Figure 6 Google Earth and area of Doddanekkundi Lake during 2002 and 2010 respectively.

   WATER QUALITY

   Table 6 Water quality of Doddanekkundi Lake with surface water limits.

   Sampling site	Doddanekkundi outlet DDO1	Dodanekkundi inlet DDI1	BIS standards for Surface waters
   pH	7.37	7.9	6.5-9
   Electric conductivity (μS/cm)	1339	1368	<1200
   Total dissolved solids (ppm)	1049	1108	<700
   Dissolved oxygen (mg/L)	0.00	1.30	>5
   Biological oxygen demand (ppm)	39.586	45.079	<5
   Chemical oxygen demand (ppm)	89.172	100.158	<30
   Nitrates (ppm)	0.29	0.41	--
   Inorganic phosphates (ppm)	1.29	1.42	--
   Total hardness (mg/L)	296	320	<200
   Calcium hardness (mg/L)	163	175	<80
   Chlorides (mg/L)	456	482	<250
   Total alkalinity (mg/L)	683	782	<600

   Water quality was distinctive of heavy pollution at both sampling sites (Table 6). Electric conductivity and total dissolved solids ranged from 1339-1368 μS/cm and 1049-1108 ppm respectively. Pollution was also measured with high BOD and COD as it reveals the organic pollution. Lake is in the verge of extinction with increasing phosphates which will lead to Eutrophication. Untreated domestic sewage accounted for high amount of hardness and chlorides. Alkalinity which measures the buffering capacity of a lake to neutralize acids from waste inflow was higher than the BIS limits. The high alkalinity explains the poor buffering capacity of water. This lake recorded more of organic pollution and needs immediate priority for conservation.

   
   CURRENT THREATS (Refer Figure 6 and Plate 6)

   1. Macrophyte cover (Eichornia sp.),
   2. Dumping of construction waste, Lake bed is encroached for construction of temple, building etc.
   3. Encroachment (filling of lake bed with construction waste)
   4. Untreated sewage inflow,
   5. No shoreline,
   6. Sludge deposition.

   PLATE 6
   

    
   
   

   7. HEBBAL LAKE

   NAME OF THE LAKE	HEBBAL
   GEOGRAPHIC DETAILS 13°2'50"N   77°35'8"E
   AREA (2000/2010)	50.8/46.14 ha
   ORGANIZATION	BBMP
   WARD / VILLAGE NAME	8-Kodigehalli
   STATUS	Moderately Polluted
   RESTORATION	Completed (Year)
   WATER CONDITION	Poor quality

    

   

    Figure 7 Google Earth and area of Doddanekkundi Lake during 2002 and 2010 respectively

   WATER QUALIT

   Table 7 Water quality of Hebbal Lake with BIS limits

   Sampling site	Hebbal inlet (HBI1)	Hebbal outlet (HBO1)	BIS standards for Surface waters
   pH	7.63	8.35	6.5-9
   Electric conductivity (μS/cm)	660	623	<1200
   Total dissolved solids (ppm)	523	523	<700
   Dissolved oxygen (mg/L)	5.12	8.13	>5
   Biological oxygen demand (ppm)	17.43	15.69	<5
   Chemical oxygen demand (ppm)	42.21	40.23	<30
   Nitrates (ppm)	0.092	0.064	--
   Inorganic phosphates (ppm)	0.15	0.18	--
   Total hardness (mg/L)	156	148.32	<200
   Calcium hardness (mg/L)	93	89.16	<80
   Chlorides (mg/L)	341	298	<250
   Total alkalinity (mg/L)	238	213	<600

   Water quality analysed has been listed in Table 7. pH ranged from neutral to slightly alkaline condition. Biological oxygen demand and Chemical oxygen demand ranged from 1569 -17.43 ppm and 40.23- 42.21 ppm which were more than BIS standard limits revealing the organic pollution in lake. Chlorides exceeding <200 mg/L was recorded at both inlet and outlet because of improper sewage management which adds to lake water at inflow region. Lake has been constructed with cement bunds during restoration which led to unavailability of shoreline region, aquatic habitats for birds and aquatic insects. Water hyacinth growth could be found at Inflow region. Ionic concentration, total dissolved solids were well within the range of BIS limits and thus the lake is said to be moderately polluted.

   
   CURRENT THREATS (Refer Figure 7 and Plate 7)

   1. No shoreline
   2. Human disturbances and Fishing
   3. Untreated sewage inflow.

   
   

   PLATE 7

    

   

   8. HENNAGARA LAKE

   NAME OF THE LAKE	HENNAGARA LAKE
   GEOGRAPHIC DETAILS         12°46'42"N   77°39'43"E
   AREA (2002/2009)	41.70/69.93 ha
   ORGANIZATION	BBMP, Irrigation tank
   WARD / VILLAGE NAME	Jigani
   STATUS	Less Polluted
   RESTORATION	NO
   WATER CONDITION	Clean – Moderately polluted.

   

   Figure 8 Google Earth and area of Hennagara Lake during 2002 and 2009 respectively.

   
   WATER QUALITY

   Table 8 Water quality variables of Hennagara Lake with BIS standards

   Sampling site	Hennagara site 1 (HNA1)	Hennagara site 2 HNA2	BIS standards for Surface waters
   pH	8.3	8.5	6.5-9
   Electric conductivity (μS/cm)	632	626	<1200
   Total dissolved solids (ppm)	505	501	<700
   Dissolved oxygen (mg/L)	5.69	5.93	>5
   Biological oxygen demand (ppm)	4.93	3.76	<5
   Chemical oxygen demand (ppm)	19.86	17.52	<30
   Nitrates (ppm)	0.076	0.066	--
   Inorganic phosphates (ppm)	0.12	0.12	--
   Total hardness (mg/L)	141	139	<200
   Calcium hardness (mg/L)	85.5	84.5	<80
   Chlorides (mg/L)	76	63	<250
   Total alkalinity (mg/L)	128	132	<600

   Chemical variables at Hennagara Lake has been listed in Table 8. Alkaline pH was recorded at both sampling sites along with an alkalinity range of 128-132 mg/L respectively. Electric conductivity and total dissolved solids were less than the explained BIS limits (refer Table) and hence water is least or not polluted with any pollution source such as untreated sewage waste. Biological oxygen demand and chemical oxygen demand ranged from 3.76- 4.93 ppm and 17.52- 19.86 ppm respectively. The main source of increase in hardness is attributed to washing of clothes. Chlorides and alkalinity were recorded as low as 63-76 mg/L and 128-132 mg/L respectively and hence this lake is considered as less polluted ecosystem.

   
   CURRENT THREATS

   1. Local human disturbances
   2. Aquatic weeds
      

   PLATE 8
   

   
   

   

   9. HESARAGHATTA RESERVOIR/LAKE

   NAME OF THE LAKE	HESARAGHATTA
   GEOGRAPHIC DETAILS     13°10'14"N   77°30'6"E
   AREA (2004/2011)	61.88-32.37 ha
   ORGANIZATION	Arkavati for drinking water
   WARD / VILLAGE NAME	Hesaraghatta
   STATUS	Clean
   RESTORATION	NO
   WATER CONDITION	Good (NO/less Water since 2010).

   

   Figure 9 Google Earth and area of Hesaraghatta Lake during 2004 and 2011 respectively. 

   WATER QUALITY
   

   Table 9 Water quality variables of Hesaraghatta Lake with BIS standards

   Sampling site	Hesaraghatta site 1 (HSA1)	BIS standards for Surface waters
   pH	9.78	6.5-9
   Electric conductivity (μS/cm)	33	<1200
   Total dissolved solids (ppm)	25.6	<700
   Dissolved oxygen (mg/L)	6.18	>5
   Biological oxygen demand (ppm)	3.45	<5
   Chemical oxygen demand (ppm)	16.9	<30
   Nitrates (ppm)	0.01	--
   Inorganic phosphates (ppm)	0.17	--
   Total hardness (mg/L)	70	<200
   Calcium hardness (mg/L)	50	<80
   Chlorides (mg/L)	22.72	<250
   Total alkalinity (mg/L)	211	<600

   Table 9 includes the results of water quality analysis of Hesaraghatta reservoir which is comparatively clean than any other lake. This reservoir water is known to be utilized only for drinking water requirements but in recent years the water level has been decreased drastically. Due to unavailability of water cover area only one sample was collected. pH of the Lake is high alkaline which depends on the type of soil. Conductivity and dissolved solids were well within the standards of surface waters. Biological oxygen demand and chemical oxygen demand reflected less organic contamination with 3.45 and 16.9 ppm respectively. Nitrates and phosphates were recorded as low as oligotrophic lake nutrient concentrations i.e., 0.01 and 0.17 ppm respectively. The source of chlorides could be considered as asphalted road and local human disturbances such as open defecation.

   
   CURRENT THREATS (Refer Figure 9 and Plate 9)

   1. Decrease in water level
   2. Human disturbances, Open defecation, fishing.

   PLATE 9

   DUMPING OF PLASTIC AND PAPER WASTE IN LAKE BED DURING VILLAGE FESTIVAL

   

   10. HOSAKERE LAKE

   NAME OF THE LAKE	HOSAKERE LAKE
   GEOGRAPHIC DETAILS        12°56'17"N   77°26'3"E
   AREA (2004/2009)	7.649/15.58  ha
   ORGANIZATION	Outskirts of Bangalore BBMP boundary
   WARD / VILLAGE NAME	Near Kommaghatta
   STATUS	Clean/ No pollution
   RESTORATION	NO
   WATER CONDITION	Good

   

   Figure 10 Google Earth and area of Hosakere Lake during 2004 and 2009 respectively.

   WATER QUALITY

   Table 10 Water quality of Hosakere Lake with BIS standards

   Sampling site	Hosakere site 1 (HSI1)	Hosakere site 2 (HSO1)	BIS standards for Surface waters
   pH	7.25	7.58	6.5-9
   Electric conductivity (μS/cm)	401.00	335.00	<1200
   Total dissolved solids (ppm)	260.00	233.00	<700
   Dissolved oxygen (mg/L)	7.50	8.20	>5
   Biological oxygen demand (ppm)	3.32	4.59	<5
   Chemical oxygen demand (ppm)	18.67	18.00	<30
   Nitrates (ppm)	0.246	0.842	--
   Inorganic phosphates (ppm)	0.004	0.083	--
   Total hardness (mg/L)	116.00	96.00	<200
   Calcium hardness (mg/L)	79.97	55.97	<80
   Chlorides (mg/L)	42.60	45.44	<250
   Total alkalinity (mg/L)	180.00	168.00	<600

   Water quality variables of Hosakere Lake is listed in Table 10. pH was showing neutral condition with a range of 7.25-7.58. Conductivity of lake was recorded as 335-401 μS/cm while total dissolved solids were 233-260 ppm. The oxygen demand was very less and within the BIS standard values with an average of 3.96 and 18.33 ppm respectively which reflected the no influence of organic matter in lake. There is no/ minimal sewage inflow into the lake and hence the chlorides level was within the limits with a value ranges from 42.6-45.44 mg/L. The shoreline region attacked several birds and dissolved oxygen level attributed to presence of fish diversity in lake. The water color was observed as clear with no macrophyte cover.

   
   CURRENT THREATS (Refer Figure 10 and Plate 10)

   
   Local human disturbances (Open defecation, washing clothes)

   PLATE 10

   

    

   

   11. HULIMAVU LAKE
   

   NAME OF THE LAKE	HULIMAVU LAKE
   GEOGRAPHIC DETAILS      12°52'13"N   77°36'18"E
   AREA	44.26 ha
   ORGANIZATION	BBMP
   WARD / VILLAGE NAME	193- Arekere
   STATUS	Polluted
   RESTORATION	NO
   WATER CONDITION	Poor.

    

   

   Figure 11 Google Earth and area of Hulimavu Lake during 2000 and 2010 respectively

   WATER QUALITY

   Table 11 Water quality of Hulimavu Lake with BIS standards

   Sampling site	Hulimavu outlet (HLO1)	Hulimavu inlet (HLI1)	BIS standards for Surface waters
   pH	8.53	8.23	6.5-9
   Electric conductivity (μS/cm)	1072.00	1070.00	<1200
   Total dissolved solids (ppm)	753.00	759.00	<700
   Dissolved oxygen (mg/L)	7.2	2.39	>5
   Biological oxygen demand (ppm)	22.3679	26.66666667	<5
   Chemical oxygen demand (ppm)	49.92	52.98	<30
   Nitrates (ppm)	0.01	0.05	--
   Inorganic phosphates (ppm)	0.21	0.17	--
   Total hardness (mg/L)	240	232	<200
   Calcium hardness (mg/L)	91.88	123.91	<80
   Chlorides (mg/L)	261.28	232.88	<250
   Total alkalinity (mg/L)	380	520	<600

   Chemical variables analyzed are listed in table 11. Hulimavu inlet water quality was distinctive form that of outlet. High amount of ionic concentration was characteristic of untreated sewage inflow and its effects on both the sampling sites. Biological oxygen demand and chemical oxygen demand ranged from 22.367-26.66 ppm and 49.92-52.98 ppm respectively exceeding the BIS standard limits which reflected the presence of organic matter. The source of organic pollution has been accounted for inflow of contaminated water. A high quantity of calcium hardness could also be observed due to increased amount of soap content in water.

   
   CURRENT THREATS (Refer Figure 11 and Plate 11)

   1. Dumping of construction waste on lake bund
   2. Local human disturbances such as washing clothes, open defecation, fishing
   3. Untreated sewage inflow into the lake

   PLATE 11

   CONSTRUCITON WORK

   STONE MINING

   WASTE DUMPING IN LAKE

   MACROPHYTE COVER

   

   12. ISRO LAYOUT LAKE

   NAME OF THE LAKE	ISRO layout LAKE/ DEVERAKERE
   GEOGRAPHIC DETAILS      12°53'52"N  77°33'18"E
   AREA	10.5 ha
   ORGANIZATION	FOREST DEPT.
   WARD / VILLAGE NAME	ISRO layout
   STATUS	Moderate pollution
   RESTORATION	Completed ()
   WATER CONDITION	Poor.

   

   Figure 12 Google Earth and area of ISRO layout Lake during 2000 and 2011 respectively

   
   

   WATER QUALITY

   Table 12 Water quality of ISRO Layout Lake with BIS standards

   Sampling site	ISRO layout inlet (IRI1)	ISRO layout Outlet (IRO1)	BIS standards for Surface waters
   pH	9.78	9.85	6.5-9
   Electric conductivity (μS/cm)	1041.00	1030.00	<1200
   Total dissolved solids (ppm)	725.00	719.00	<700
   Dissolved oxygen (mg/L)	9.76	6.42	>5
   Biological oxygen demand (ppm)	24.22	22.58	<5
   Chemical oxygen demand (ppm)	53.33	50.67	<30
   Nitrates (ppm)	0.432	3.797	--
   Inorganic phosphates (ppm)	1.691	1.251	--
   Total hardness (mg/L)	352.00	316.00	<200
   Calcium hardness (mg/L)	259.93	239.94	<80
   Chlorides (mg/L)	195.96	195.96	<250
   Total alkalinity (mg/L)	460.00	360.00	<600

   Water quality analyzed for ISRO Layout Lake has been listed in Table 12. Variation in water quality was observed in terms of Biological oxygen demand (BOD) and Chemical oxygen demand (COD) concentration in both the sampling sites. BOD and COD ranged from 22.58-24.22 ppm and 50.67-53.33 ppm respectively. Inorganic phosphate concentration was found to be high (range, 1.251-1.69 ppm), which led to lake Eutrophication. Total hardness of water ranged from 316-352 mg/L exceeding the BIS limits because of temple waste accumulation in lake bed. Even though, the lake water reveals low ionic concentration, it is slightly polluted with high organic matter due to the local human disturbances such as inflow of temple waste water and materials such as plastics, garlands etc., in lake water.

   
   CURRENT THREATS (Refer Figure 12 and Plate 12)

   1. Dumping of garbage, Foul smell, Poor maintenance,
   2. Sewage of ISRO layout to lake inflow, Temple waste, etc.

   PLATE 12

   TEMPLE  LAKE

   WEED COVER NEAR LAKE OUTLET

   SEWAGE INFLOE SITE

   THERMACOL WASTE IN LAKE WATER

   

   13. JAKKUR LAKE

   NAME OF THE LAKE	JAKKUR LAKE
   GEOGRAPHIC DETAILS      13°5'12"N   77°36'34"E
   AREA	59 ha
   ORGANIZATION	BDA
   WARD / VILLAGE NAME	Jakkur
   STATUS	Moderate pollution
   RESTORATION	August 2009- August 2010 (Incomplete)
   WATER CONDITOIN	Poor (Before restoration)

    

   

   Figure 13 Google Earth and area of Jakkur Lake during 2002 and 2009 respectively.  

    

   WATER QUALITY

   
   Table 13 Water quality of Jakkur Lake with BIS limits mentioned.

   Sampling site	Jakkur Inlet (JKI1)	Jakkur Outlet (JKI2)	BIS standards for Surface waters
   pH	8.02	8.07	6.5-9
   Electric conductivity (μS/cm)	1240.33	1325.67	<1200
   Total dissolved solids (ppm)	870.67	947.00	<700
   Dissolved oxygen (mg/L)	4.67	6.91	>5
   Biological oxygen demand (ppm)	24.20	23.60	<5
   Chemical oxygen demand (ppm)	79.31	48.72	<30
   Nitrates (ppm)	0.016	0.015	--
   Inorganic phosphates (ppm)	0.026	0.030	--
   Total hardness (mg/L)	326.67	346.67	<200
   Calcium hardness (mg/L)	93.33	100.00	<80
   Chlorides (mg/L)	286.84	295.36	<250
   Total alkalinity (mg/L)	163.33	163.33	<600

   Among all water quality variables listed in Table 13, Electric conductivity (range, 1240.33-1325.67 μS/cm), total dissolved solids (range, 870.67-947 ppm) and chlorides (range, 286.84- 295.36 mg/L) concentrations showed a higher values at both sampling sites which was beyond the BIS standards as mentioned in Table 13. This water condition was representing characteristic polluted water due to improper maintenance of sewage inflow at inflow region. Organic content in lake was high at inflow with 79.31 ppm of COD and 24.2 ppm of BOD while a lesser concentration at outlet region i.e., 48.72 ppm and 23.6 ppm respectively. Higher hardness and calcium at both the sites revealed higher pollution due to increased human disturbances such as washing clothes, waste dumping etc. macrophyte cover at inflow showed a lower oxygen penetration rate and hence low oxygen level compared to outlet region.

   
   CURRENT THREATS (Refer Figure 13 and Plate 13)

   1. Domestic sewage run-off of Jakkur village,
   2. urbanization
   3. Inflow of fields and plantations surrounding lake

   PLATE 13

    

   

   14. KANNUR LAKE

   NAME OF THE LAKE	KANNUR  LAKE
   GEOGRAPHIC DETAILS      13°6'0"N   77°39'4"E
   AREA	20.5 ha
   ORGANIZATION	Outskirts of BBMP boundary
   WARD / VILLAGE NAME	Kannur
   STATUS	Moderately polluted
   RESTORATION	NO
   WATER CONDITION	Clean- Moderate pollution

   

   Figure 14 Google Earth and area of Kannur Lake during 2003 and 2009 respectively. 
   

   WATER QUALITY

   Table 14 water quality of Kannur Lake with BIS standards

   Sampling site	Kannur site 1 (KNR1)	Kannur site 2 (KNR2)	BIS standards for Surface waters
   pH	8.57	8.16	6.5-9
   Electric conductivity (μS/cm)	478	505	<1200
   Total dissolved solids (ppm)	331	357	<700
   Dissolved oxygen (mg/L)	10.57	10.89	>5
   Biological oxygen demand (ppm)	6.36	5.49	<5
   Chemical oxygen demand (ppm)	22.72	20.98	<30
   Nitrates (ppm)	0.01	0.02	--
   Inorganic phosphates (ppm)	0.11	0.14	--
   Total hardness (mg/L)	111	93	<200
   Calcium hardness (mg/L)	70.5	61.5	<80
   Chlorides (mg/L)	62	43	<250
   Total alkalinity (mg/L)	132	160	<600

   The water quality of Kannur Lake revealed less or no impact of sewage and contamination at both the sampling sites. All the chemical variables analysed were well within the BIS surface water standards except an alkaline range pH. BOD values were slightly above the BIS limits reasoning the organic pollution due to local human disturbances such as open defecation, washing clothes, mining and inflow of agricultural waste into lake water. A good amount of oxygen availability was recorded and thus inhabits fish diversity.

   
   CURRENT THREATS (Refer Figure 14 and Plate 14)

   1. Mining
   2. Local human disturbances
   3. Agricultural run-off

   PLATE 14

   

   

   15. KOMMAGHATTA LAKE

   NAME OF THE LAKE	KOMMAGHATTA LAKE
   GEOGRAPHIC DETAILS       12°55'48"N   77°28'2"E
   AREA	ha
   ORGANIZATION	BDA
   WARD / VILLAGE NAME	Kommaghatta
   STATUS	Clean/ No pollution
   RESTORATION	September 2009- August 2010 (COMPELTED)
   WATER CONDITION	Good.

   

   Figure 15 Google Earth image and area of Kommaghatta Lake during 2000 and 2011 respectively.

   WATER QUALITY

   Table 15 Water quality of Kommaghatta Lake with BIS standards

   Sampling site	Kommaghatta inlet 1 (KMI1)	Kommaghatta inlet 2 (KMI2)	Kommaghatta outlet (KMO1)	BIS standards for Surface waters
   pH	9.32	9.01	8.98	6.5-9
   Electric conductivity (μS/cm)	812.00	782.00	764.50	<1200
   Total dissolved solids (ppm)	594.00	558.00	548.50	<700
   Dissolved oxygen (mg/L)	5.98	4.55	6.14	>5
   Biological oxygen demand (ppm)	12.96	25.30	13.71	<5
   Chemical oxygen demand (ppm)	24.00	84.00	28.00	<30
   Nitrates (ppm)	0.049	0.056	0.066	--
   Inorganic phosphates (ppm)	0.038	0.020	0.022	--
   Total hardness (mg/L)	264.00	298.00	286.00	<200
   Calcium hardness (mg/L)	24.05	15.23	32.87	<80
   Chlorides (mg/L)	121.41	109.48	119.42	<250
   Total alkalinity (mg/L)	276.00	248.00	170.00	<600

   Water quality analyzed for Kommaghatta Lake before restoration has been mentioned in table 15. Inlet water pH exceeding the BIS limits ranging from 8.98-9.32. Dissolved oxygen level was less at inlet sites while was 6.14 mg/L at outlet. Organic matter was reflected by high amount of Biological and chemical oxygen demand which ranged from 12.96-25.30 ppm and 24-84 ppm respectively. Higher amount of hardness was also recorded at inlet 2 (298 mg/L) and outlet (286 mg/L) which was reasoning the local human disturbances and domestic sewage concentration. The lake before restoration was polluted with organic matter which has been reduced after restoration but lacks the biodiversity present prior to restoration.

   
   CURRENT THREATS (Refer Figure 15 and Plate 15)
   Untreated sewage and road runoff

    

   PLATE  15

   

   16. KAMMAGONDANAHALLI LAKE

   NAME OF THE LAKE	KAMMAGONDANAHALLI LAKE
   GEOGRAPHIC DETAILS       13°3'54"N   77°31'41"E
   AREA	11.29 ha
   ORGANIZATION	BDA
   WARD / VILLAGE NAME	12- Shettihalli
   STATUS	Highly Polluted
   RESTORATION	NO
   WATER CONDITION	Poor

    

   

   Figure 16 Google Earth image and area of Kommagondanahalli Lake during 2000 and 2010 respectively.

   
   
   

   WATER QUALITY

   
   Table 16 Water quality of Kommagondanahalli Lake with BIS standards

   Sampling site	Kommagondanahalli outlet (KMH1)	Kommagondanahalli inlet (KMH2)	BIS standards for Surface waters
   pH	8.73	8.08	6.5-9
   Electric conductivity (μS/cm)	419.00	1452.00	<1200
   Total dissolved solids (ppm)	329.00	1136.00	<700
   Dissolved oxygen (mg/L)	7.30	8.60	>5
   Biological oxygen demand (ppm)	23.32	19.33	<5
   Chemical oxygen demand (ppm)	50.92	45.21	<30
   Nitrates (ppm)	0.68	0.58	--
   Inorganic phosphates (ppm)	1.120	1.340	--
   Total hardness (mg/L)	277	281	<200
   Calcium hardness (mg/L)	238.00	215.00	<80
   Chlorides (mg/L)	233	256	<250
   Total alkalinity (mg/L)	220	234	<600

   Water quality of Kommagondanhalli Lake has been listed in Table 16. Significant change has been noticed in terms of water quality from inlet to outlet. Inlet sampling site had high concentration of electric conductivity (1452 μS/cm), total dissolved solids (1136 ppm), phosphates (1.340 ppm), total hardness (281 mg/L) and calcium (215 mg/L). Organic matter measured through biological and chemical oxygen demand was recorded more than the BIS limits for surface standards. This was due to the dumping of solid waste, plastic waste near the outlet while the untreated sewage inflow accounted for pollution at inlet site. A high macrophyte cover occupied one side of the lake and led to the Eutrophication of lake.

   
   CURRENT THREATS (Refer Figure 16 and Plate 16)

   1. Dumping of solid and construction waste on lake bund
   2. Growth of macrophyte and thus Eutrophication
   3. Local human disturbances.

    PLATE 17
   

   DUMPING OF CONSTRUCTION WASTE

   WATER EUTROPHICATION

   WEED COVER

   

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