1 State of Water Environment
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1 State of Water Environment 1.1 Availability of Water Resources Nature has endowed Gujarat with limited fresh water. The total renewable fresh water available, including the annual runoff from within the state and that allocated from the neighbouring states, and all the natural recharge of groundwater, is 54,593 MCM (IRMA, 2001). This gives a per capita renewable fresh water availability of 1137 m3 per annum for the year 2001 (IRMA 2001) and 830 m3 per annum for the year 2011 (Nawlawala 2011). Therefore, as per water stress index1, the state reached the status of “water stressed” in the year 2001 itself and over the decade per capita availability has decreased significantly. It is also predicted that the availability will be 738 M3 in 2015 and 601 M3 in 2025. But it need to be noted that the availability of water is heavily skewed towards south and central Gujarat, which has 69.5% of the total renewable fresh water. 1932 2000 1839 2001 2011 1500 1137 1000 876 830 734 526 465 427 500 247 0 Kutch Saurashtra North Gujarat South Gujarta Total Figure 3-1 Changing Per Capita Availability of Water (in M3 per Annum) 1 The Falkenmark water stress index measures per capita water availability and considers that a per capita water availability of between 1000 and 1600 m3 indicates water stress, 500–1000 m3 indicates chronic water scarcity, while a per capita water availability below 500 m3 indicates a country or region beyond the ‘water barrier’ of manageable capability (Falkenmark and Widstrand, 1992) The study by Amarasinghe et.al.(2005) confirms these observations. The study has used disaggregated data at the river basin level to assess the water supply and demand across the river basins of India. According to the study, Saurashtra, Kachchh and North Gujarat falls under the river basin named as westerly flowing river group 1 (WFR 1), which is the only basin of the country having physical water scarcity with an highest degree of development (132%) and Ground water abstraction ratio (194%), with a depleted fractions of 92 percent. A broad picture of the distribution of the arid and semi-arid blocks support the above mentioned water scarcity, as 17 blocks in the state are arid and 79 blocks are semi-arid bringing the total to 96 blocks of the total 192 blocks. The annual replenishable ground water resource of the state for 2008-09 has been estimated as 18.43 billion cubic metres (BCM). (GoI, 2010). Net Annual Ground Water Availability is 17.35 bcm and the Annual Ground Water Draft is 12.99 bcm. Agriculture sector remains the predominant consumer of ground water resources by drafting about 92% of total annual ground water draft i.e. 11.93 bcm while only 1.05 bcm is for Domestic & Industrial use which is about 8% of the total draft. The figure for net draft of groundwater considering the present utilization indicates that a substantial portion of the total potential (about 23 per cent) still remains untapped. There has been an increase of 36 percent in the net utilizable groundwater in 2009 as compared to 1997 (17.35 BCM to 12.8 BCM). Studies conducted by the State Ground Water Board in several regions of the state also draw attention to the severe water scarcity. In Ahmedabad district for example the ground water level was 63 meters in 1997, and it went to 100 meters in 2011. The rising demand from the urban population as well as from the rapidly growing industries was seen to be responsible for this. Again, the report of the Ground Water Management Investigation Centre of the Government of Gujarat (2011) has revealed that water tables in Gujarat are declining rapidly even from “confined” water tables. The average water table form the confined water tables was 51.86 meters in 2001, and it want to 65.89 meters in 2011. This trend was observed in Central Gujarat, North Gujarat as well as in the Eastern Gujarat. Uncontrolled withdrawal of ground water by farmers has been responsible for this trend (CGWB 2011). 1.2 Stage of Ground Water Development The level of Ground Water Development for the entire state is 75%. According to the assessment of Central Ground Water Board as on March 2009, in 5 out of 26 districts all belonging to North Gujarat, the gross annual drafts has exceeded the available groundwater resources and they are categorized as “over-exploited” districts. Kachchh is the only district where groundwater development is greater than 90 percent and is categorized as critical districts. Sabarkantha and Porbandar are categorized as semi-critical while the remaining 17 districts are considered safe as the level of development is less than 70 percent and there is scope for further exploitation in these districts. CGWB has also assessed 223 talukas/units for computing the stage of ground water development. Out of the 223 assessment units (Taluka), 27 have been categorized as “Over-exploited”, 6 as Critical, 20 as Semi- critical, 14 as Saline and 156 as safe. Map 3-1 Stage of Groundwater Development in 1997 Map 3-2 Stage of Groundwater Development in 2009 Table 3-1and Figure 3-2 show the comparison of the level of ground water development in 1997 and 2009. The major changes in the status of groundwater resources are: . Prominent Change in the level of groundwater development mostly in Southern Hills especially in Dangs (22%), North West arid (6%) and North Gujarat (5%) . The number of districts falling in ‘over-exploited category’ with more than 100 percent groundwater development increased from 3 in 1997 to 5 in 2009. However taluka level data; shows that the total number of safe/white blocks has increased from 52 percent in 1997 to 70 percent in 2009. That is, the problem talukas have decreased from 45 percent to 24 percent over the same period, whereas the saline talukas have increased twice from 7 in 1997 to 14 in 2004 and continued to remain saline till date (Table 6). It has been observed that in Vadodara, Kheda and Bharuch districts of central Gujarat especially coming under Narmada command, the talukas which were coming under over- exploited category in 1997 has now shifted to either semi-critical or safe category in 2009. A similar trend has been followed by Amreli and Junagadh districts of Saurashtra region. The worst affected region is Kachchh where 70 percent of talukas are problem talukas (more than one-third of which are OE), followed by North Gujarat, which has 56 percent problem talukas (with more than 70 percent OE talukas) (Chart 15). For taluka wise distribution of this data, please refer to annexure. 100 80 5 31 1 60 3 2 8 1 40 27 6 18 20 42 6 9 20 0 1997 2009 1997 2009 Over-Exploited Critical Semi Critical Over-exploited Critical Semi-critical Safe Figure 3-2 Comparison of 1997 and 2009 Level of Development of Ground Water in Gujarat 80 70 60 50 % 40 30 20 10 0 Kachchh North Gujarat South and Saurashtra Central Gujarat Problem Talukas Table 3-1 Figure 3-3 Percentage of Problem Talukas wrt to GW status Comparison of 1997 and 2009 Stage of Development of Ground Water Level of Development (%) S.N District 1997 2009 Percent change (%) North Gujarat 120.7 126.2 5% 1 Ahmedabad 93 102 10% 2 Banaskantha 111 137 23% 3 Gandhinagar 146 165 13% 4 Mahesana 165 148 -10% 5 Sabarkantha 89 79 -11% North west arid 86 91 6% 6 Kachchh 86 91 6% Middle Gujarat 61 58 -5% 7 Kheda 73 63 -13% 8 Panchmahals 46 50 9% 9 Vadodara 64 60 -6% Saurashtra 68 67 -2% 10 Amreli 71 68 -4% 11 Bhavnagar 63 65 3% 12 Jamnagar 57 66 15% 13 Junagadh 78 70 -10% 14 Rajkot 70 70 1% 15 Surendranagar 71 64 -9% Southern Gujarat 46 48 4% 16 Bharuch 60 56 -6% 17 Surat 32 40 25% Southern Hills 23 28 22% 18 Dangs 1 16 1453% 19 Valsad 45 40 -12% Table 3-2 Categorization of Talukas with Respect to Stage of Development of Groundwater across 12 years Category 1997 2002 2004 2009 Over-Exploited 31 30 31 27 Critical/Dark 8 12 12 6 Semi-Critical/Grey 43 63 69 20 Saline 7 - 14 14 Safe/White 95 - 97 156 Total Assessment Units/Talukas 184 105 223 223 Source: Udiwal and Patel, 2010; GEC, 2005 & CGWB, 2009 1.2.1 Causes of Over-Exploitation The prime cause of over-exploitation is the rising demand for groundwater from agriculture. In groundwater irrigated areas, decisions on cropping pattern and cropping intensity, which are the predominant determinants of agricultural demand for groundwater, are being taken largely independent of the ease of ground water availability. Thus, water intensive crops (which are perceived to be remunerative) have tended to be grown even in the face of scarcity of groundwater. The problem has been compounded by the availability of subsidized power in the state. Moreover, electric supply is not metered and a flat tariff is usually charged. The total availability of surface and ground water in the state is 50,000 MCM. However, the demand for agriculture is higher and is being met by over exploitation of ground water in water scarce regions of the State. Table 3-3 below shows net area irrigated by various sources of water in the State. Data shows that besides canal and wells, the rural population has been depending upon tanks and villages ponds also. Table 3-3 Trends in Net Irrigated Area by Source Net Irrigated Area by Source (Area in 00 hectares) Year Govt.