Receptions in hotels would no longer be allowed and only three goats could be slaughtered to feed guests, Beled Hawa's commissioner told the BBC.
Spending limits of $600 (Â£500) on furnishings for a couple's new home and up to $150 for the bride price had also been set, Mohamud Hayd Osman said.
It is not unusual for a groom's family to spend about $5,000 on a wedding.
The BBC Somali service's Bashir Mohamed says this amount includes the bride price, wedding reception, outfits and jewellery for the bride as well as new furniture.
"Islamic teachings indicated that getting married should be cheap," Mr Osman told the BBC Somali service.
The decision to restrict spending on "wild partying" and other expenses had been taken after officials met to find out why 150 children had recently been born out of wedlock in the town.
"Young women were refusing to get married unless a fortune was spent on wedding gold and household furnishings," he said.
Times were already difficult in Beled Hawa, which neighbours Kenya, because of the drought and unemployment - and the high cost of weddings was another contributing factor in people leaving the area, the commissioner said.
"A young woman must be supported to get married to the young man she chooses... so the community can grow," he said.
He said $600 should be enough to purchase a double bed, table and chairs as well as crockery and cutlery.
Traditionally the events around a Somali wedding go on for seven days.
A Somali town has banned lavish weddings to encourage young people to marry and stop them migrating.