India, like many other countries/regions, has a water scarcity issue. But what makes India's water troubles unique is that, not only does it has water sharing conflicts with other countries, but also between States themselves. This is because States, not the Central Government, allocate the use of water resources. To arbitrate these inter-state conflicts, India has a dedicated act and various tribunals that award each State its water rights. 
According to the Falkenmark index, a widely used index of how water scarce a region is, India is "water stressed": 
Water Stress: 1,000 - 1,700 cm3
Water Scarcity: 500 - 1000 cm3  
Absolute Scarcity: < 500 cm3
The annual per capita water availability in the country has decreased to 1545 cm3 in 2011 from 1816 cm3 in 2001. This figure is projected to reduce to 1401 cm3 by 2025 and 1191 cm3 by 2050, as a combined result of several factors, most notably an increasing population and economic growth through industrialization. As a result of growing stress and approaching scarcity, water is becoming a conflicted resource in India. India has been battling with both inter-state water sharing disputes and transboundary disputes with countries like Pakistan, China, Nepal and Bangladesh.
Surface water has always been a bone of contention between various Indian States and between India and other countries. This is because it only has 630 km3 of usable surface water, which falls short of growing water demand for agricultural, industrial and household usage. The agriculture sector is the largest driver for water demand in India and the main source of inter-state river water conflict. Most of the conflict-ridden states are investing more in the production of water-guzzling crops like wheat, rice and sugarcane, causing even more demand for surface water. Against this backdrop it is quite obvious that every State is becoming more cautious to protect the needs of its agrarian sector.
To make the situation murkier, the construction of major and minor storage reservoirs for irrigation in the upper riparian region (from where water sources originate) are jeopardizing the requirements of lower riparian states (where water flows downstream to) in India. Growing energy needs, leading to the construction of dams for the production of hydropower are also creating resentment. Similar reasons, mainly hydropower diplomacy, are exacerbating the transboundary water-sharing conflicts between India and its neighbors.
To sum it up, water-sharing conflicts are due to:
  • The intricate nexus between food, water and energy 
  • Water has become a matter of national security 
  • Politicization
  • Inefficient and underdeveloped water governance institutions 
Inter-State Water Sharing Disputes
India has a number of inter-state water sharing disputes. Post-independence, the earliest traces of the disputes can be tracked down to the year 1969. This led to the formation of Tribunals for the adjudication of water sharing conflict in accordance with the Inter-State Water Disputes Act (ISWD) of 1956. In India, most interstate water sharing disputes have escalated because of the construction of dams on interstate rivers.
The Narmada water sharing dispute between Gujarat, Maharashtra and Madhya Pradesh started in 1961 with the construction of the Sardar Sarovar dam on Narmada River in Gujarat. The Central Government created the Narmada Water Dispute Tribunal (NWDT) on October 1969 to adjudicate the sharing of Narmada water. As per the award, after each riparian State was allocated its water share and with directions to reduce the height of the dam, the Tribunal gave its final consent to construct the dam. It is an ongoing conflict with issues related to the resettlement and rehabilitation of the affected communities. 
The Krishna river water sharing dispute between Andhra Pradesh (AP), Maharashtra and Karnataka is mainly with regards to the ratio of Krishna water share allocations to the respective three States. Krishna Water Dispute Tribunal–I  (KWDT) gave its award on May 1979. As per the award, Andhra Pradesh was allocated a share of 811 TMC (1 TMC = 1 Billion Cubic Feet), Maharashtra 560 TMC and Karnataka 700 TMC. But over the years, with growing water needs and the construction  of the Almatti dam by Karnataka, the conflict continues. All of these States have approached the Government of India from time to time. KWDT-II was constituted in April 2004 and the final verdict was given on November 2013. Recently with the bifurcation of AP and Telangana, the Krishna water conflict is still ongoing.
                                                  Almatti dam constructed by Karnataka on Krishna river
Cauvery river water sharing dispute between Karnataka and Tamil Nadu revolves around the failure of the upper riparian Karnataka to comply with the water allocation verdicts of Cauvery Water Dispute Tribunal (CWDT) and the orders of the Supreme Court (SC). Karnataka has breached the orders of the Tribunal and the SC by not releasing the apportioned water quantities to Tamil Nadu, mainly during the deficient monsoon seasons. Even though the final water sharing award was announced by CWDT in 2007 it is an ongoing conflict.
Ravi and Beas water sharing dispute between Punjab and Haryana is with regards to the construction of the Satluj-Yamuna link to divert Satluj water from Punjab to Haryana. Punjab has strongly objected the construction of the diversion link and wants to transfer the acquired land back to the farmers as per the Punjab Termination of the Agreements Acts (PTAA). But in November 2016, the Supreme Court invalidated PTAA and ordered Punjab to start the construction of this link.
Apart from these major interstate conflicts, other on-going conflicts include the Vansadhara River Water Dispute between Odisha and Andhra Pradesh; Mahadayi River Water Dispute between Maharashtra, Karnataka and Goa; Indirasagar (Polavaram) Project dispute between Maharashtra, Madhya Pradesh (including Chhattisgarh), Orissa, Karnataka and Andhra Pradesh; Babhali Barrage Issue between Maharashtra and Andhra Pradesh; and Mulla Periyar Dam issue between Kerala and Tamil Nadu.
India shares a number of transboundary rivers with countries like Pakistan, China, Nepal, Bhutan and Bangladesh. The country has formulated successful bilateral water-sharing treaties with its respective neighbors but still conflicts have not been resolved due to several gaps and omissions in the clauses of the treaties. Almost all the bilateral water treaties between India and other countries were signed during 1960s and 70s. They did not foresee the emergence of water scarcity challenges in the light of climate change and more variable rainfall patterns.
India and Pakistan still have several issues concerning the construction of hydropower projects on the western rivers (Indus, Jhelum and Chenab) that were apportioned to Pakistan after the signing of the Indus Water Treaty in 1960. To meet its growing energy demands, India has and plans to construct dams on the Indian side of western rivers. Pakistan has strongly objected and has continuously approached international arbitrators to intervene. The recent case of the verdict on Baglihar dam by the International Court of Arbitration, The Hague is a case in point. The treaty has no clause on the sharing of water in light of falling groundwater levels and climate change concerns.
In the case of India and Nepal, the Mahakali Water Treaty was ratified and resigned in 1996 to resolve the issue of water sharing. But due to some ambiguous clauses with regard to the construction of Pancheshwar dam, it is the most resented treaty among Nepalese. The signing of Mahakali treaty was supposed to provide economic benefits to Nepalese but the citizens are of the view that this treaty favors India and has not provided the benefits to Nepal as it was supposed to. Case in point is the construction of Pancheshwar dam which has not be executed due to the treaties ambiguous clauses for monitoring its establishment. Public resentment towards the construction of this dam is very high in Nepal.
Some clauses of the Ganges Treaty signed in 1996 between India and Bangladesh are considered detrimental to Bangladesh. One of the objectives of this treaty is to govern the dry season flow of the Ganges and to seek ways to augment flows in the Farakka barrage in the Indian side and Hardinge Bridge in the Bangladesh side. But research has shown that the dry season flow has significantly declined in the Hardinge Bridge after the commission of the Farakka barrage thereby severely impacting the agriculture and allied sectors of Bangladesh.
Furthermore, hydro-politics have garnered more attention in this region as India plans to construct several dams on Bramhaputra river in the state of Arunachal Pradesh and Assam; and several other dams in the state of Sikkim on river Teesta. If constructed and made operational the harm to Bangladesh is potentially great. The fact that India and Bangladesh share around 54 rivers and only have one bilateral water sharing treaty is rather shaky ground on improving water cooperation in both countries.
Proposed dams in Bramhaputra basin 1: Sankosh, 2: Manash, 3: Subansiri (under construction), 4: Dihang, 5: Lohit, 6: Tipaimukh, 7: Jogighopa barrage 
With regards to Brahmaputra water sharing, India and China have failed to forge a bilateral water sharing treaty. One positive development has been the signing of an Memorandum of Understanding (MoU) in 2013 through which China agreed to provide more hydrological information to India at the start of the flood season. Despite the most recent MoU, robust information sharing is still lacking. Even though both countries have agreed to protect their vested water interests, the Chinese dam building spree and diversion links in the Yarlung Zangbo basin of Tibet is creating anxiety for India and raises concerns for possible future water conflicts.
                                                             Dams built and under construction by China on Yarlung Zango (Brahmaputra river in India) 
Apart from gaps and omissions in the bilateral treaties, water sharing disputes with other countries are not finding a permanent solution because of stringent securitization and geo-politicization of water. This securitization has led to difficulty in accessing even basic information about transboundary rivers, including stream and sediment flow, water withdrawal and usage. The report by the Asia Foundation, Strengthening Transparency and Access to Information on Transboundary Rivers in South Asia, describes transboundary water management and cooperation in South Asia as highly nationalistic, technocratic and zealously securitized. It further states that in all four South Asian countries (Bangladesh, India, Nepal and Pakistan) data and information on the selected rivers are collected and held by government departments in a fragmented manner and information is not systematically collected at a 'river basin' level. Also, water information is shared informally with countries who have better relations.
Territorial disputes have further exacerbated the transboundary water-sharing conflicts and made the situation worse. Disputed borders are both the cause and symptom of tension between neighbours in the Indus, Ganges and Brahmaputra basin that have exacerbated the trust deficit. India and China have territorial disputes along the border of Arunachal Pradesh. India and Bangladesh have disputes over the alluvial or ‘char’ land as it changes course with the river morphology. Nepal and India still have a territorial dispute over a 75 km2 land along the Kalapani River. Kashmir is the bone of contention between India and Pakistan whereas disputed boundaries between India and China includes 25,900 km2 area in the regions of Snag, Demchok and Aksai Chin.
Is there a Permanent Solution to end water conflicts? 
Water is currently treated as a zero-sum resource within and outside India. It will be nearly impossible to do anything on the domestic and transboundary front until water sharing is treated through mutual sharing, transparency and effective governance. Due to adversarial adjudication process and litigation delays, the temporary constitution of water tribunals and an institutional vacuum when implementing the Tribunal awards, inter-state water sharing disputes conitnue.
On the domestic front:
  • There is a need to address these specific issues. Creation of a permanent dispute tribunal can solve governance issues to an extent.
  • Also since inter-state disputes are mainly caused by dam construction on interstate rivers, there is a need to review and contain this issue wherever possible through proper checks and balances.
With regards to transboundary water sharing, there are several flaws in the way water-diplomacy is handled between India and other South Asian countries and China. But sooner or later the countries have to take the transboundary agenda at face value and come up with mechanisms to make water a resource of economic benefit rather than a source of conflict or war.
Given the huge economic growth potential that South Asia encompasses, it is time that respective governments come forward to formulate a basin-wide approach to sharing of water in the lines of other successful models like the Mekong River Commission and the Nile River initiative.
On the transboundary front:
  • A regional water governance institution should be formulated having mechanisms and processes for the clear exchange of data and information. A regional transboundary water sharing policy should be drafted and implemented in this regards.
  • Since water is a state subject in India, in the case of transboundary water sharing, limited powers should be given to the States as this would lead to other national governments to interact only with the Central government.
  • Efforts should be made to de-securitize water and enhance public and institutional access to water-related data.
  • Lastly, for successful implementation of transboundary agreement--policies, legislation, resources and management practices of each country should be harmonized with each other and efforts should be taken to first stabilize internal water management and then scaled up to transboundary water management through a building block approach.