Third Mumbai (KSC New Town): The Complete Overview

What Third Mumbai Is

Third Mumbai — also called Mumbai 3.0, KSC New Town, or Karnala-Sai-Chirner New Town — is the name now used for a planned city being built across 124 villages in Raigad district, Maharashtra. It comprises of 323.44 Sq.km. of area. The project's core predecessor is NAINA (Navi Mumbai Airport Influence Notified Area), which was folded into the larger KSC New Town along with the land influenced by the Mumbai Trans Harbour Link (MTHL/Atal Setu).

Also known as Navi Mumbai Airport Influence Notified Area (NAINA) and originally announced in 2013, the new town is designed to manage haphazard growth around the forthcoming Navi Mumbai International Airport. After the inauguration of the sea link bridge between Mumbai and Navi Mumbai called Atal Setu, also known as Mumbai Trans Harbour Link, the notified area around the bridge was also included in the project and collectively these areas came to be called Third Mumbai.

Who Is Building It

By notification dated 15 October 2024, the Government of Maharashtra appointed MMRDA as New Town Development Authority (NTDA) for 124 villages in Uran, Panvel and Pen tehsils in Raigad district. On 21 October 2024, MMRDA officially named the city Karnala-Sai-Chirner New Town, after the three villages Karnala, Sai and Chirner within the notified area.

This effectively replaced CIDCO in the role it had long held over NAINA. The government revoked CIDCO's appointment as the Special Planning Authority for 80 villages in the Navi Mumbai Airport Influence Notified Area and 33 villages in the Khopta New Town Notified Area, handing planning powers to the MMRDA-led NTDA instead. The New Town is being planned by MMRDA primarily on the framework of CIDCO's Navi Mumbai development model, including its approach to funding infrastructure through land value rather than cash grants.

Official Notified Area, Villages and Districts

The notified KSC New Town area is drawn from four separate pre-existing planning zones, all in Raigad district:

• 80 villages under the Navi Mumbai Airport Influence Notified Area (NAINA)
• 33 villages under the Khopta New Town Notified Area
• Two villages under the Mumbai Metropolitan Regional Plan
• Nine villages under the Raigad Regional Plan

The 124 villages fall across Uran, Panvel and Pen tehsils in Raigad district. The area immediately around Pen Municipal Council itself has been excluded from the new planning zone. The area is named for three of its constituent villages: Karnala, known for the Karnala Bird Sanctuary and Karnala Fort; Sai, located in the Western Ghats; and Chirner, situated near Jawaharlal Nehru Port Trust (JNPT), one of India's largest container ports.

Why It Exists

Third Mumbai was announced in 2013 to prevent haphazard development of the upcoming Navi Mumbai International Airport area, and was previously known as the Navi Mumbai Airport Influence Notified Area (NAINA). The scope grew after the opening of the Atal Setu sea bridge, which brought a new belt of land under an 'influence area' designation that MMRDA sought to control directly rather than leave to piecemeal development.

The stated aim of the planning is to provide better housing, infrastructure and robust transport facilities for the increasing population of the Mumbai Metropolitan Region. Officially, the KSC New Town is envisioned as a model of avant-garde urban planning built on integration of smart technologies, green infrastructure and climate-resilient urban systems, and mixed-use neighbourhoods designed to reduce commuting distances. Appointing MMRDA as NTDA over these developable areas is also meant to let the authority generate revenue that can be reinvested into the large-scale infrastructure the region needs.

Current Status (as of August 2026)

KSC New Town remains at the policy-and-planning stage; no part of it is yet an operating township. The key milestones reached so far:

• Land policy approved: The Government of Maharashtra, via Government Resolution dated 16 March 2026, approved the Land Acquisition and Land Allocation policy for the New Town Development Authority and future MMRDA projects. The policy moves away from purely compulsory acquisition toward a partnership/land-pooling model, under which consenting landowners are offered a share of the developed, infrastructure-ready land back in exchange for their raw plots, following the CIDCO model used in Navi Mumbai. Landowners who do not opt for pooling can choose direct cash compensation as per the LARR Act, 2013 at prevailing market rates, among other options.
• Consent process open: MMRDA has put an NTDA – KSC New Town consent form online for landowners to fill in.
• Surveys complete, master plan pending: Drone mapping and LiDAR surveys required for planning have already been completed, and the master plan for KSC New Town is expected to be finalised by August 2026. The Urban Development Department has appointed the Singapore-based consultancy Surbana Jurong Infrastructure to prepare the comprehensive development blueprint.
• Planning regulations: MMRDA is to prepare detailed planning proposals and development regulations for the notified area, and has also been granted land acquisition powers with a mandate to allocate budget provisions for this process. Planning proposals are to be prepared as per the provisions of the Maharashtra Regional and Town Planning Act, 1966.

Beyond MMRDA's own disclosures, industry trackers reported through mid-2026 that MMRDA's 2026-27 budget set aside a specific allocation for KSC New Town and that a handful of villages already had sanctioned local development plans, though these figures have not been independently verified against MMRDA's own budget documents and should be treated as provisional.

Headline Connectivity

KSC New Town's case rests on infrastructure already built or opening around it, rather than infrastructure inside it:

• Atal Setu (Mumbai Trans Harbour Link): A roughly 21.8 km six-lane link, with about 16.5 km of sea bridge and 5.5 km of elevated road on land, connecting Sewri in Mumbai to the Nhava Sheva–Chirle side of Navi Mumbai. It opened in January 2024 as India's longest bridge and longest sea bridge. It directly touches the KSC New Town notified area on the Chirle side.
• Navi Mumbai International Airport (NMIA): the airport sits inside/adjacent to the notified area and is the project's core rationale. Reported milestones include domestic operations beginning in late December 2025 and international flights following in 2026, with passenger volumes scaling up through early 2026 — figures that should be confirmed against official airport/AAI releases for exact counts.
• Suburban rail and metro: CIDCO is already executing a Mumbai-to-Navi Mumbai airports metro linkage, and a proposed 'Gold Line' metro would connect Chhatrapati Shivaji Maharaj International Airport in Mumbai directly with Navi Mumbai International Airport. A Panvel–Karjat suburban rail line, which would serve the eastern edge of the notified area, has also been under construction.
• Road network: The area also has access to the Mumbai-Pune Expressway.

What Happens Next

The immediate milestone to watch is the master plan. MMRDA's Singapore-appointed consultant, Surbana Jurong Infrastructure, is targeting a comprehensive development blueprint for KSC New Town by August 2026, which would set out land-use zoning, road and utility networks, and a phasing strategy for the 124 villages. Once the master plan and detailed planning proposals are notified, the practical work of land pooling, road-cutting, and utility-laying can begin village by village rather than across the whole 324 sq km at once.

Realistically, this is a multi-decade build-out. Independent market analysts covering the project have suggested that substantial, livable development of even an initial phase is unlikely before the early 2030s, given the scale of land assembly and infrastructure still required. Private investment interest has already been signalled: in January 2025, Blackstone Group announced plans to invest up to $11 billion in Maharashtra over 3–5 years, with $5 billion earmarked specifically for projects in Third Mumbai. How much of that materialises, and on what timeline, will depend on the master plan and land-pooling uptake that follow through the rest of 2026.