At 16:30 on Saturday 31 October 2026, the first cars rolled onto the new Ponte Visletto above Cevio. The deck is 146.4 m of continuous five-span beam, 8 m wide including kerbs, with two Corten steel box girders under a reinforced-concrete slab. Four more lines run inside the structure: drinking water, wastewater, electricity and telecom, all built into the bridge according to the Ticino DT/DFE presentation of 12 June 2025. For the upper Maggia valley, this crossing is the corridor its services travel through.

This bridge carries a valley’s taps, light switches and phone signal on the same girders as the evening traffic. I recognise that load case, and I respect it.

What is inside the deck

The section is composite. Weathering steel boxes take the bending, and concrete forms the abutments, piers and deck slab. Four circular piers, each 1.30 m in diameter, carry the beam. Two stand in the riverbed and two in the floodplain, and every structure sits on bored piles. The canton’s June 2025 presentation calls the round section “ottimale dal punto di vista idrodinamico e morfologico”, and laRegione reported that it reduces scour pits “indipendentemente dall’angolo di attacco della corrente”. That matters on a braided Alpine river whose channel can move in a single night.

The lesson the design answers

In the night of 29–30 June 2024, two spans of the old crossing collapsed. In Bulletin Electrosuisse 4/2025, OFIMA director Marco Regolatti and Andrea Baumer, OFIMA’s head of dams and environment, recorded what went with it. The whole upper valley lost power and telecom, and with the regional SES grid cut in several places, the valley’s power stayed off “für mehrere Tage”. At Bignasco the federal gauge reached about 1,000 m³/s according to OFIMA, “möglicherweise auch mehr”. Then the collapse cut the gauge’s power supply, and its measurements stopped. Until the new bridge opened, the army’s temporary bridge kept the valley moving. It was limited to 32 t, ran alternating one-way traffic on lights, and sat low enough to risk closure in a flood.

Bundling services into one deck saves cost, access and landscape. The price is that the crossing’s resilience becomes the valley’s resilience.

←TODAY: One 146.4 m deck in Cevio carries a road plus four utility lines, opened on 31 October 2026. →3012: Every crossing is drawn as the bundle it carries, and its model lists each line by name and owner. Fulcrum: A bridge built for the next flood has to be designed as the valley’s nervous system as well as its road.

The response: line, piers, piles, model

The new crossing sits further upstream than the old line, which reduces erosion. Works started on 7 July 2025, and all foundations were finished by October 2025, with the riverbed work timed to the autumn low flow. “Il deflusso è monitorato giornalmente,” said Fabiano Martini, head of the Area operativa of the Divisione delle costruzioni. To shape the bed around the piers, the canton commissioned a 1:40 physical model of about one kilometre of the Maggia, from Cevio to the mouth of the Rovana. Laboratorium3D in Biasca built it. According to the Ticino water service, which Laurent Filippini heads, La Télé/ATS reported that the subsoil “est extrêmement instable depuis les intempéries dévastatrices de juin 2024”. A flume with real sediment is well suited to that kind of moving-bed question.

Upstream, the people whose work goes unseen did their part. OFIMA’s reservoirs held back more than 9.2 million m³ during the event, and Lago di Sambuco rose 2.2 m in 12 hours. All OFIMA plants but Peccia stayed in operation, and Robiei’s pumps lifted water into the Cavagnoli and Naret reservoirs. The people who kept them running deserve this line.

Consorzio VISLÈ won a three-phase total-contractor competition (seven firms invited, four bids, two shortlisted). Its specialists were Lurati Muttoni Partner SA, Andreotti & Partners SA, Sciarini SA, Martino Pedrozzi and Officina del Paesaggio. Piero Marchesi, head of the Dipartimento del territorio, and Cevio mayor Wanda Dadò attended the opening. The canton paid the full CHF 10.5 million. It had set December 2026 as the target and opened in October. PAZ has followed the June 2024 storms from the rail side, in the Mattertal Tunnel piece.

Atelier: Any office drawing a station, an underpass or a footbridge already hosts somebody else’s cables and pipes, usually as one grey “MEP” layer nobody owns. Offices that have lived through an outage learn to ask who loses service, and for how long, when one structure closes. Monday move: in the current Rhino model, split every line that rides on a structure onto its own named layer, recording the service and the owner.

Hack: Scale the Maggia onto the lab floor the way a 1:40 river model does, with Froude similarity. When gravity drives the flow, velocity scales with the square root of the length ratio and discharge with its power of 2.5. The numbers below are illustrative and are not the lab’s results.

L = 40                      # length scale 1:40
v_model = 0.5               # m/s measured in the flume
print(v_model * L**0.5)     # prototype velocity, about 3.2 m/s
print(1000 / L**2.5)        # 1,000 m³/s in the river is about 0.099 m³/s in the lab

One flood peak becomes roughly 99 litres per second, small enough for a pump in Biasca.

From where I stand, late in the 2070s, the crossings we regretted were seldom the ones that fell. They were the ones whose services had nowhere else to go. If you are building within a public work this year, ask for the alternative route for water, power and signal on paper. Ask, too, who maintains each line in year sixty. Open your model and name every line your structure carries.