From harbor to homes: the dock that becomes urban district

Initially, Rotterdam thought about building additional parking for residents of the residential towers in Kop van Zuid. But in 2017, a more ambitious project to redevelop the Rijnhaven ripened. The harbor basin would be transformed into a modern living and residential area. This metamorphosis, with swimming facilities, an office with restaurant on the water, floating city parks and mixed-use building blocks with 3,000 homes, offices, business facilities and stores, was chronicled in a master plan that included a large-scale damming of the dock. As the engineer in charge, René Groeneveld is monitoring this preliminary work for the city.   

"The Rijnhaven dates back to 1890 and was barely maintained during that period. But due to the favorable location of the harbor mouth in relation to the river flow, the siltation was not that bad at about 2.5 meters. The sediment actually scrapes past," René says of the dredging that started in 2021. Initially, main contractor Boskalis brought 142,000 cubic meters of silt to the slufter, which was later increased to 160,000 cubic meters due to a change in plans. "The original master plan from 2017 covered an attenuation in a straight line. But New York architectural firm Van Valkenburgh Associates three years later redesigned a more undulating park, with more dynamic shapes, to which the dredging had to adapt."

The master plan also brought with it the need for a new zoning plan. Damping work is proceeding in two phases. "Currently, we are damping two-thirds of the total, with an additional over height to let it settle. What excess height remains, we will use to attenuate in that second phase," said René, "But below the waterline, the attenuation is now completely finished according to the latest plan. About 1.2 million cubic meters of sand we are filling now, and afterwards another 200,000 cubic meters. This includes about 10 meters under water and 5 meters above it."

Containment of stability risks

The reclaimed sand will serve not only for an urban beach, but also for the construction of three blocks of 1,000 homes each and the 42,000 m2 land park. The total attenuation covers 65,000 m2. "Both the housing and the park will come on the newly raised land, we are bringing 16 meters of sand," René clarifies. "In the harbor, we dredged a lot deeper and installed a dam to minimize edge stability effects, and via two 'total stations' we are constantly monitoring the works to identify problems in time. We jacked up the Luxor Theater - along with the application of Argex - to avoid any stability issues and stress from settlement of the attenuation." 

City or port?

International research shows that half of infrastructure works go smoothly over budget. What about community money for the Rijnhaven? "Good for now," says René. "Continuously we steer on budget, adjusted according to increased material costs, indexation, the effect of the war in Ukraine and so on. Because a lot has happened in the seven years between plan and execution works. Depending on the course of settlement during the consolidation process, additional sand may still be needed, within the project we have included a risk item for this in order to absorb this possible setback. The area to be covered is huge." 

Yet another issue during the yard process has been successive changes in nitrogen emissions legislation. "When the dredging works started in 2021, according to the law we included a rock-hard NOx limit in the tender. But a construction exemption followed later, including infra works, so there was no need for a NOx limit in the attenuation contract. After an appeal, the exemption expired again, in 2022, so we were forced to make the machines more durable in a hurry. Today we have to meet an annual emission limit for nitrogen. We are steering very hard on that, because even in the port we are close to strictly regulated Natura 2000 areas such as Hoek van Holland and the Biesbosch." 

In conclusion, the question still arises whether the Rijnhaven is now a differently filled-in piece of harbor or still a full-fledged city district? "Both," René says with a laugh, "The basin is about 210,000 m2 in size, so two-thirds of the surface area will remain port with accompanying character, but it is also an extension of the city." The park and beach will be finished first, starting in 2028, and the housing will be completed around 2031.