Catalonia's public health agency has proposed strict new measures to regulate cannabis clubs in the region, amid claims that Barcelona is on its way to rivalling Amsterdam as a smoker's haven.

Amsterdam has tightened restrictions on cannabis sales just as the number of clubs in Spain has proliferated from some 40 in 2010 to more than 700 today, say smokers' groups. The Catalan capital is home to more than half of these clubs.

From swanky clubs that span three floors to others with a small room and a few plastic chairs, the clubs take advantage of a provision in Spain's drug laws that allow marijuana to be grown and consumed for private use.

The clause has turned Spain – and especially Barcelona – into what Spanish media call the "Holland of the South". But unlike Amsterdam's coffee shops, which are open to the public, Spain's clubs are for members only.

Skirting the membership policy is fairly easy; while many clubs stick to a policy of requiring new members to be sponsored by existing ones, a number of clubs allow prospective members to register online or via telephone. Some clubs have employees who hand out promotional flyers in the street, promising to ease the registration process.

The past two years have seen hundreds of these cannabis clubs spring up in Barcelona, creating a thriving industry as other sectors suffered the economic crisis. Catalonia's cannabis clubs now count some 165,000 members, who rack up an estimated €5m (£4m) in sales each month, according to El País newspaper.

Local officials in Barcelona have been watching closely. In June, the city imposed a one-year moratorium on new licences for cannabis clubs. Calling it a "preventative" measure, deputy mayor Joaquim Forn said it would give the city some breathing space to regulate the industry and "avoid it becoming a serious problem".

A first draft of the regulations, drawn up by the public health agency of Catalonia and obtained by El País, sets out strict regulations on the cultivation and transport of the drug and clubs' membership in an effort to chip away at the legal grey zone in which the clubs currently operate.

Memberships will be limited to Spanish residents, taking aim at the region's growing reputation for cannabis tourism. Members will have to be 21 years of age or older and belong to the club for at least 15 days before being given access to marijuana.

Other measures include forcing clubs to register their plants and undergo an annual inspection, in an attempt to give regional authorities a more complete idea of the product on offer in the region.

The maximum quantity that members will be allowed to access each month has yet to be determined, said the proposal, but is expected to be somewhere between 60 to 100 grams a month (2-3.5 ounces). With some clubs currently with as many as 5,000 users, the draft noted that a maximum number of members must also be determined.

The proposed regulations were welcomed by the Catalonia Federation of Cannabis Associations, one of many associations that has been pushing the government to better regulate the sector. While the association took issue with the draft regulations' proposal of a fixed schedule that would force the clubs to close for a three-hour lunch each day and close by 8pm most days, the regulations were "positive in general", a spokesman, Jaume Xaus, told El País. Many of the clubs, he noted, already follow similar regulations.

One notable omission, he said, was to set a criteria for municipal licences. Without this, he worried, the granting of permits would be left to individual mayors, allowing for discrepancies to arise.

Cannabis clubs have also become popular in the Basque country in recent years, registering more than 10,000 members and leading the regional government to begin drawing up regulations for the clubs earlier this year.