The first proposal for a town in the IJmeer arrived in 1965, when the architects Jo van den Broek and Jacob B. Bakema published the Pampus Plan. It would have settled 350,000 people on artificial islands east of Amsterdam — a city the size of Bordeaux, conjured from the lake in a single decade. National policy went the other way. The Dutch state pushed growth outward to the new towns instead: Almere on the Flevoland polders, expansion in Purmerend and Hoorn, the Bijlmermeer south of Amsterdam, the enlargement of Diemen. Pampus was shelved. The idea of building on water rather than draining it stayed in the Dutch policy bloodstream, waiting for a generation that would need it again.

Amsterdam came back to its lake in the 1980s, hemmed in on every side: Schiphol airport to the west, the protected polders and the Amstel to the south, the nature reserves of Landelijk Noord across the IJ. The only direction left for the city to grow was east, into the IJmeer itself. The municipality approved IJburg in 1996. Opponents — worried about the ecological cost to the lake, the loss of open water, the precedent of building on a freshwater lakebed — pushed for a binding referendum. On 19 March 1997 they got their vote. They won the room and lost the war. The 133,000 against could not clear the 155,000 threshold. Construction began the following year.

Building an island in a shallow lake is, in principle, simple: dump enough sand to break the surface, give it time to settle, drive piles for the buildings. In practice, IJburg's first phase took almost two decades. Six islands rose from the IJmeer: Steigereiland — Jetty Island; Haveneiland West and East — Marina Island; and the three Rieteilanden — Reed Islands — Large, Small, and East. The Enneus Heerma Bridge, designed by the English architect Nicholas Grimshaw and opened in 2001, carries the main road and the IJtram from Zeeburgereiland onto Steigereiland in two 75-meter spans, one of the larger bridges in Amsterdam. Grimshaw designed a second smaller bridge to span the gap to Haveneiland. The Benno Premsela Bridge was added in 2004 to connect the eastern end to Diemen. The pedestrian-and-cyclist Nescio Bridge — named for the writer whose pen name was Latin for I do not know — terminates on the south side in a spiral cycle ramp that has become a small landmark in itself.

Three more islands were planned for Phase 2: Centrumeiland — Centre Island; Strandeiland — Beach Island, the biggest of all; and Buiteneiland — Outer Island. Construction stalled when a Superior Administrative Court annulled the Phase 2 building permit, ruling that the developers had not given sufficient weight to the local environment. By 2020 the work had resumed under revised plans. Homes are now rising on Centrumeiland. Strandeiland was still being pumped up from the lakebed, sand layer by sand layer, when the most recent figures were compiled — a literal beach island being made of beach. The temporary Strand IJburg beach on the western side of Strandeiland has become a summer destination for Amsterdammers; plans call for moving and making it permanent once construction allows.

IJburg's lifeline to Amsterdam is the IJtram, tram line 26 to Centraal Station. It was designed as a fast tram with widely spaced stops, and is the only line in Amsterdam that carries non-folding bicycles — a maximum of two at a time, a quiet but radical bit of municipal design. As IJburg has grown, peak frequency has climbed to 15 trams an hour. The Piet Heintunnel constrains the line to one tram in each direction at any moment for safety reasons, so the GVB began running paired trams in 2020 to add capacity. A bus route, 66, runs the only other road connection — the Benno Premselabrug — to Bijlmer ArenA. A bicycle ferry, route F9, opened in January 2023. The longer plans imagine extending tram 3 or 14 east, or eventually building a metro line from Amsterdam to Almere via a tunnel under IJburg. Each plan reads like an admission that the original transit infrastructure was sized for a smaller IJburg than the one the city is now actually building.

IJburg is now the third-richest postcode in the Netherlands. Theo van Gogh has a park on Haveneiland, named for the filmmaker who was murdered in Amsterdam in 2004. The Diemerpark — one of the city's largest — runs parallel to the Rieteilanden, with a small sandy beach overlooking the new neighborhood from across the bridge. None of this would exist if 22,000 more Amsterdammers had voted no in March 1997. The lake would still be lake. The IJtram would not exist. The question IJburg leaves behind — about referendum thresholds, ecological consequences, the right of a city to grow into water it does not yet legally own — is the kind of question the Netherlands has been asking itself in different forms since the first dike. The answer this time was: build it anyway.