Efficient Water Management Techniques for Higher Agricultural Productivity: Case Studies from Northern Karnataka

Gujarat State is located in the western part of India, it is well known for entrepreneurship of its peoples. Water resources in the state are very much unevenly distributed. There are very high rainfall areas in the southern part of state, whereas the northern and western parts face desert like climate. Hydrogeologically there are diverse aquifer systems. Some form prolific aquifer system like alluvial formations of North and Central Gujarat plains. There are also hard rock formations like Granites, Deccan Basalts which form poor aquifers. Due to frequent and persistent droughts water resources management has been a challenge in northern and western parts of the state. Total annual availability of water in the state is estimated at 51 BCM/ out of which surface water contribution is 38 BCM, whereas groundwater accounts for 13.58 BCM. The groundwater plays a very important role in agriculture as well as water supply in this drought prone state. The total annual Groundwater Recharge has been assessed as 22.37bcm and Annual Extractable Ground Water Resources as 21.25bcm. The Annual Ground Water extraction has been assessed as 13.58bcm and Stage of Ground Water extraction as 64%. There are 248 assessment units (talukas) out of which 25 Talukas have been categorized as ?Over- exploited?, 5 are ?Critical?, 11 are ?Semi-Critical?,194 as ?Safe? and 13 saline talukas in the state. A well-planned strategy is required for management of water resources in the state. Number of water conservation and augmentation measures have been taken up in the state in the form of Sujalam Suflam Yojna, Sauni Yojna, Participatory irrigation management, ATAL-JAL, Hydrology Project, Interlinking of Rivers to name a few. Further steps suggested for conservation and sustainable use of ground water can be augmentation of groundwater resources through Artificial Recharge, revival of ponds, reuse and recycling of wastewater, protection of water sources from pollution, conjunctive use of surface and ground water, etc

Palghar, Thane, Raigad, Ratnagiri, Sindhudurg and Greater Mumbai districts of Maharashtra form the Konkan Coastal belt of Maharashtra. In the coastal areas the immediate effect of high groundwater development is often sea water intrusion. Although there were sporadic studies by earlier workers (Umrikar et al., 2007, Gupta et al. 2010) into some reported isolated cases of seawater intrusion in the coastal areas, this has been a maiden attempt to decipher the extent of seawater intrusion in the entire coastal tract of Maharashtra.The area is underlain by Dharwarian meta-sediments (Lower Precambrian age), Deccan Trap lava flows (Upper Cretaceous to Lower Eocene age), Laterites (Pleistocene age) and Coastal alluvial deposits (Recent to Sub-Recent age). Groundwater occurs under phreatic condition in the Coastal and riverine alluvium, laterites and weathered/fractured rocks. The area has been covered by systematic hydrogeological surveys, reappraisal Surveys and groundwater monitoring by CGWB. in these formations depth to water levels range from 0.6 m bgl to 8.07 m bgl. Groundwater is mildly alkaline with pH range of 6.9 to 9.0. Electrical conductivity ranges from 61 to 29370 ?S/cm at 25?C. Only two Samples from Dapoli in Raigad district show EC values higher than 3000 ?S/cm at 25?C. In general, water quality is good and suitable for domestic use and irrigation. In order to confirm the sea water intrusion, ionic ratios like Na:Cl, and Cl:CO3 + HCO3, were computed. From the analysis it is found that about 2 to 10 km wide coastal belt and the inland tidal backwaters are affected by salinity intrusion. It is revealed that about 55% of the analysed samples have indicated salinity ingress. The extent of sea water intrusion is more in the southern part progressively diminishing towards northern area. The maximum effect is observed in Sindhudurg district followed by Ratnagiri, Raigad, Palghar and Greater Mumbai.Over-exploitation of groundwater in pockets and diminishing seaward freshwater flow in the rivers are the major reasons for sea water ingression. Regulation of groundwater development in the coastal area and areas adjacent to estuaries, maintaining adequate stream flow, stopping of riverbed sand mining, construction of tidal regulators at suitable places and creation of fresh water barrier through rainwater harvesting and groundwater recharge are essential to control further sea water intrusion in the area.

Drylands of arid Rajasthan are well known for Drought and hot Desert having diversified hydro-geological conditions. Potential aquifer systems include unconsolidated (Quaternaries deposits), semi-consolidated (Tertiary Sandstone, Lathi Sandstone etc.) and fissured consolidated formations. Groundwater level is generally deep especially in western Rajasthan, where it reaches even 150m below land surface. Quality of groundwater is poor in many parts due to geogenic and anthropogenic reasons. Stage of groundwater development in the State is 139.88% with 185 blocks categorized as over-exploited. Groundwater related issues include deep and declining water levels, low groundwater recharge, over-exploitation, drying up of potential aquifer systems, high salinity, fluoride and nitrate concentration, industrial pollution, water logging and lack of appropriate water management. Management options include supply side and demand side measures i.e. water conservation, regulation, protection and especially structural measures for augmentation of resources by large scale artificial recharge of aquifers, for which financial provisions by the Government/incentives to individuals need to be introduced. Scope for artificial recharge of aquifers exists on account of availability of thick permeable geo-formations, deep & declining water levels, and availability of surplus monsoon water in northwest India, which otherwise goes waste flowing to the neighbouring country. Regulatory measures including notification of 35 block areas, mandatory provision for issuance of NOC for industries/ infrastructure/mining projects for controlled groundwater withdrawal. etc. are being taken up by Govt. organizations. State Water Policy is in place and rooftop rainwater harvesting is to be made mandatory for all buildings. State Ground Water Legislation and State Ground Water Authority need to be constituted and regulatory measures be enforced by Rajasthan Government in line with CGWA. There is need for integrated participatory approach of water management. Rajasthan being the most water deficit State in India, deserve to be given ?Special Status for Water Resources? for financial and other purposes by Government of India.

In general, Chhattisgarh state is underlain by hard rocks with limited groundwater potentials. But decline of rainfall in most parts of the state is limiting surface water resources too. Agriculture is mostly rainfed, paddy being the main crop in the state. Groundwater is the main source of irrigation and a major source of drinking water. Cavernous limestones/dolomites form the most potential aquifers yielding up to 50 lps as in Bastar, Baloda Bazar and Bilaspur districts. Proposal for construction of energized irrigation dug/bore wells under PMKSY-HKKP-GW scheme in 109 blocks (stage of extraction within 60%) of 7 aspirational districts will enhance ground water irrigation of 7467 ha land. The stage of extraction has already escalated from 5.11% (1990) to 44.43% (2017) which will be escalated further with ongoing and future development programs. The State should undertake conservation of groundwater through regulation, protection and augmentation of the water resources by implementing rainwater harvesting and artificial recharge, along with adoption of rainfed agriculture, drip or sprinkler irrigation, pricing policy for commercial ground water extraction, exploration and planned development of yet unknown aquifers through exploratory drilling aided by remote sensing, geophysics . Based on declining groundwater level trends areas totalling 16,410 sq. km have been demarcated for rainwater harvesting and artificial recharge creating sub-surface ground water storage potential of 1030.11 MCM and an additional irrigation potential of 148430 ha. Further, groundwater pollution from geogenic and anthropogenic sources like high fluoride, arsenic, uranium, sulphate, nitrate as in Rajnandgaon, Durg, Bilaspur, Raipur and Kwardha districts is also a potential threat to the utilisable resources.This paper attempts at a holistic overview of sustainable development and management of ground water resources of the state considering the huge hydrogeological, geophysical and chemical database in the state.

The Chhattisgarh state covers a total geographical area of about 135192 Sq. Km with subtropical climate, characterized by extreme summer and moderate winter having average rainfall of about 1300 mm. Physiographically, the area is characterized by three distinct landforms namely Bastar plateau in the South, the plain of Mahanadi river and its tributaries in the central part and the hills of Chhotanagpur plateau in the northern region. The major river basins in the state are Brahmani, Godavari, Ganga, Mahanadi and Narmada . The total catchment of these river basins is about 13559 kilometers. The Mahanadi Basin is the largest basin covering an area of about 76150 square kilometers out of 141589 square kilometers, nearly 4.3 percent of total geographical area of the country. Chhattisgarh has 2 percent population and 3.2 percent of total surface water resources of the country. The utilizable surface potential in the state if properly harnessed can irrigate about 4.3 million hectares area against the existing potential of 1.38 million hectare. Due to various anthropogenic activities, urbanization, industrialization etc, the quality and quantity of water have been adversely affected. The rivers Hasdeo, Indravati, Kharun, Apra etc. are polluted due to industrialization and urbanization in various parts of the Chhattisgarh. To check the pollution, proper management of solid/liquid waste of various industries is needed. Beside these, use of biofertilizers instead of chemical fertilizers, pesticides etc should be promoted. Effective water management strategies combined with watershed treatments like soil conservation, afforestation, desilting of rivers, rainwater harvesting etc are needed to maintain the health of the river basins of Chhattisgarh. The Jal Shakti Abhiyan started by the Government of India is a highly welcome move in this direction.