The Aqua Line (Line 3) is a rapid transit metro line of the Mumbai Metro in the city of Mumbai, Maharashtra, India. The route is Mumbai Metro's first underground line with 27 stations, 26 of which are underground stations and one is at-grade. It is the first metro line to be fully underground in Mumbai. The line runs from Cuffe Parade in the far south of Mumbai to Aarey JVLR in the north centre, and includes connections to other metro lines, monorail, suburban rail, inter-city rail, and Mumbai's International Airport. The Aqua Line is expected to reduce road congestion as well as the load on the Western Line between Bandra and Churchgate.
The project was implemented is operated by the Mumbai Metro Rail Corporation Limited (MMRCL). The total cost of this line is estimated at . The project was funded by five major groups: MMRCL, Padeco, MMRDA, and JICA; the last of which provided a soft loan of .
The section of the line between Bandra Kurla Complex and Dharavi stations includes a long twin-tunnel passing under the Mithi River. This is the second under-river metro rail tunnel in India after the first tunnel underneath the Hooghly River on Kolkata Metro Green Line. The first phase of the project was inaugurated on 5 October 2024 by Prime Minister Narendra Modi. The ₹14,120 crore BKC to Aarey Jogeshwari-Vikhroli Link Road section of the line, which consists of 10 stations. Phase 2A of the line stretching from BKC to Acharya Atre Chowk, covering an additional five stations, was inaugurated on 9 May 2025, under the hands of CM Devendra Fadnavis and other officials present. The final 10.99 km stretch of the line from Acharya Atre Chowk to Cuffe Parade was inaugurated by Modi, along with the Navi Mumbai International Airport on 8 October 2025.
The construction of this metro route faced hurdles from environmentalists and activists lodging numerous PILs over cutting of trees in various regions accompanied with a larger protest in Aarey over the carshed construction. PILs were either dismissed or did not succeed, as both the Supreme Court and the Bombay High Court cited the importance of the metro project. Initial projections for the Aqua Line anticipated daily ridership of nearly 1.5 million passengers; however, subsequent estimates indicate that actual usage has reached only about 150,000 passengers per day.
Background A metro line from Colaba to Bandra was announced in January 2004, as part of a master plan unveiled by the Mumbai Metropolitan Region Development Authority (MMRDA). The plan encompassed a total of of track, of which was proposed to be underground. The MMRDA unveiled plans for an extended Colaba-Bandra-SEEPZ metro line in 2011. According to its earlier plans, a metro line from Colaba to Bandra was to be constructed, running underground for from Colaba to Mahalaxmi, and then on an elevated track from Mahalaxmi to Bandra. The MMRDA decided to extend the line to the Chhatrapati Shivaji Maharaj International Airport to increase ridership. The Colaba-Bandra-SEEPZ line was estimated to cost , have 27 stations, and would be the city's first fully underground metro line."Views on Colaba-Seepz underground metro sought". DNA India. 14 December 2017. Retrieved 30 December 2011. at Nariman Point, BKC, MIDC, SEEPZ, and elsewhere. According to the MMRDA, an underground metro will minimise land acquisition and disturbance to traffic during construction compared to an elevated metro.
The Mumbai Metro Rail Corporation Ltd (MMRC), registered under provisions of Company Act, 1956, was constituted as a fully owned company of the MMRDA on 30 April 2008, as per state government directives. On 27 February 2012, the Central Government gave in-principle approval to the plan for the Aqua Line. In April 2012, the MMRDA announced plans to grant the MMRC increased management autonomy, in an effort to enhance the project's operational efficiency."Mumbai Metro likely to get autonomy status: MMRDA". DNA India. 27 April 2012. Retrieved 3 May 2012.
Funding In early 2012, the MMRDA conducted talks with officials at Chhatrapati Shivaji International Airport (CSIA) to finance or construct the line's three stations at the airport and GVK SkyCity, a proposed nearby commercial development."Development body in talks with CSIA". The Indian Express. 14 January 2012. Retrieved 16 January 2012. Mumbai International Airport Limited (MIAL) agreed to bear the cost of constructing the three stations, which was expected to total 777 crore. MIAL was willing to contribute to the metro's construction because of the potential increase in passenger convenience. In 2014, MIAL estimated the cost of developing the metro lines in the airport as 518 crore. MIAL inserted a 'metro component' in the User Development Fee charged at Mumbai Airport from 2016 to February 2023 to raise this amount. The charges of Rs 20 and Rs 120 per domestic and international departure respectively, were levied until the target sum was raised.
In August 2012, the Urban Development Ministry rejected the Planning Commission's proposal to implement the Aqua Line in a public-private partnership (PPP) mode, having found the mode unsatisfactory for the Delhi Airport Metro Express. The ministry instead proposed a funding pattern with a ratio of 20:80 between the Centre and the State. Of the State equity, 45% was proposed to be through a loan from the Japan International Cooperation Agency (JICA)."Ministry rejects Plan for Mumbai Metro-3". Daily Pioneer. 17 August 2012. Retrieved 21 August 2012.
In 2016, JICA commenced providing financial assistance for the project in the form of a soft loan through the MOUD (Ministry of urban development) as a "pass through assistance" at an annual rate of interest of 1.4% (interest free for monies given to consultants). This amounts to for the project. JICA will fund 57.2% of the equity. The soft loan has an interest rate of 1.44%. The other finance will come from the central and state equity of 10.4% each, sub-debt by the central government (4.4%), sub-debt by the state (7%), property development and impact fee (4.3%), stakeholder contribution from the Mumbai International Airport Ltd. (3.4%) and MMRDA grant/aside funding (2.9%).
In March 2019, the MMRC managing director Ashwini Bhide stated that the actual completion cost of the project was .
Aqua LineSourceAmount% Equity by Central Government 9.57Equity by State Government9.57Sub-debt by Central Government 4.22Sub-debt by State Government12.97Property development + impact fee2.68Stakeholder contribution (MIAL)2.08ASIDE funding / MMRDA grant1.82JICA loan57.09Total100
Planning The Union Cabinet granted clearance to the Aqua Line on 27 June 2013. The cabinet also decided to convert Mumbai Metro Rail Corporation (MMRC), the existing state-level special purpose vehicle formed to implement metro projects, into a joint venture company of the state and central governments with equity participation. The MMRC's board consists of five members each from state and central governments. The MMRDA presented their metro line plan to the Brihanmumbai Municipal Corporation on 13 February 2014.
Aqua Line was approved by the state cabinet on 26 February 2014. Aqua Line is being implemented through the engineering, procurement and construction (EPC) model. The foundation stone for the project was laid by Chief Minister Prithviraj Chavan in a bhoomi pujan ceremony at Andheri on 26 August 2014, in the presence of Union Urban Development minister Venkaiah Naidu. The move was described by the media as a cosmetic gesture, as the developers of the project had not yet been decided and actual construction was expected to begin only by December 2014. The date of the ceremony was a few days before the code of conduct for the 2014 State Assembly elections would come into force, which would prohibit the ruling Congress-NCP government from politicising the ceremony. Some citizens protested against the State government at the ground breaking site. They protested the slow implementation and cost escalation of the Mumbai Metro project. Tendering for the project was delayed by the re-organization of the MMRC from a wholly owned entity of the State Government, to a joint venture between the Union and State Governments. Although the State Government received the file for reconstituting the company in October 2013, it gave approval only in July 2014.
In December 2014, the MMRC appointed a consortium led by Hong Kong-based AECOM Asia, in a joint venture with Padeco, Japan, LBG Inc. USA and Egis Rail, France as the general consultants for the implementation of the Aqua Line project. The agreement between the two parties was signed on 26 May 2015. On 6 July 2015, the MMRC unveiled a new logo, designed by Design Orb, for the Aqua Line. UPS Madan, Director, MMRC and Metropolitan Commissioner, MMRDA, explained, "The earlier logo was designed with an elevated Metro-3 corridor in mind as was planned originally. The new logo presents the organisation more appropriately as its more relevant, fresh and robust". He also noted that the earlier logo had been designed while the MMRC was owned by the State Government, while it was now a joint venture between the State and the centre.
The MMRC had to rehabilitate 2,807 families for the project. Most of the families were relocated to Kurla and Chakala. The MMRC also provided free hotel accommodation to people residing in old, dilapidated buildings along the metro corridor that were in danger of collapsing during tunneling work. The majority of such buildings were located in the Girgaum-Kalbadevi belt in South Mumbai.
In March 2022, the Government of Maharashtra announced plans to extend the Aqua Line southbound from Cuffe Parade, adding one new station – Navy Nagar. The extension would be long, and would cost an additional . In August 2022, the MMRCL invited bids for Detailed Project Reports (DPRs) for the extension.
Bidding The MMRC called for pre-qualification bids in September 2013. Bidders for the work on tunnels and stations were to submit their bids by 30 October 2013. On 31 January 2014, the bid document was modified and the annual turnover requirement was reduced to "average annual construction turnover of not less than US$175 million defined as billing for civil infrastructure work completed or in progress over the last five years ending in March 2013". Sanjay Sethi, managing director of MMRC, stated, "The annual turnover requirement must have been set with the idea of attracting specific companies to the project. However, the Japan International Cooperation Agency (JICA) felt that consortia or joint ventures are a combination of management contractors and construction contractors. In all Metro projects, the annual turnover is the starting point for bidding based on which we should not restrict applications. The issue was also raised by several potential bidders." The last date for the submission of pre-qualification bids was extended to 10 March 2014. Fourteen pre-qualification bids were received for the design and construction of underground stations and tunnels for the Aqua Line. The 14 bidders were: Afcon-KMB, CEC-ITD Cementation India-TPL, CTCEC-Pan India Infrastructures Pvt Ltd, Dogus-Soma Constructions, IL&FS-CR256 (China Railway), JKumar-CRTG, Larsen & Toubro-STEC, Mosmetrostory-Hindustan Construction Company, OHL-SK Engineering & Construction, Pratibha-GDYT Consortium, Sacyr-CMC-Essar, Salin Impreglio-Gammon, Strabag-AG-Patel Engineering and Unity Infrastructure-IVRCL-CTG. Tenders to construct the car depot at Aarey colony were floated by the MMRC in July 2014.