Seeking to reassure people, the borough government cleaned and disinfected the flower-decked boats and docks, and enforced special hygiene rules, but there were few tourists or revelers for the reopening. That contrasts with the crowds in a good year, like 2015, when about 2 million people visited the floating gardens.

The tourism industry in Mexico accounts for 8.7% of the country’s gross domestic product, and has been left gasping by the pandemic as both domestic and foreign tourists stay home. Mexico City, which has nearly 90,000 confirmed coronavirus cases and about 10,000 deaths, is still on the second-highest form of alert.

Tourism has long been particularly important for Xochimilco, where borough officials have long struggled to defend the islands, known as “chinampas,” from encroaching development. People build houses on the unstable islands, which were created by the Aztecs by laying down woven reed mats, covering them with dirt and planting trees or other plants to root the floating islands to the bottom of the shallow lake.

As he poled his boat, known as a “trajinera,” through the waterways with a long barge pole, one boatman noted ruefully that even once people feel reassured about Xochimilco health precautions, many Mexico City residents may no longer have the money to do visit because of the pandemic’s economic blow.

The borough government sent squads of workers in protective suits through the boats, docks and surrounding markets early Friday to spray disinfectant.

Boat personnel are required to wear face masks and face shields, and to limit crowd size there is a ban on the traditional practice of tying up two boats so passengers can party in larger groups. The boats can usually hold about 20 passengers in a pinch, but are now limited to 12 passengers. The tradition is to order food from vendors in passing boats, eat, drink and listen to mariachi music.

The boats will be allowed to operate only between 9 a.m and 5 p.m. In the market, only every other artisan stall can be open on a given day.

However, there may be a bright side to Xochimilco’s dilemma: With all bars and nightclubs in Mexico City closed due to the pandemic, the boats, floating gardens and nearby market may be one of the few places in the city of almost 9 million inhabitants where revelers can still drink, other than at home.

With so many people locked up at home for months, there are hopes that many city residents will want to go to Xochimilco and soak up the atmosphere — and a “michelada,” a local drink of beer, salt, sauce and lime.