City Hall glowed pink and yellow as San Francisco rang in the Festival of Lights with dancing, feasting and glow-in-the-dark hula-hooping.

The Bhangra & Beats Night Market’s Diwali celebration — the city’s first official observance of the Indian holiday — drew thousands of people Friday to Battery and Clay streets in downtown, which crackled with fireworks, flickering clay lamps and grills cooking up fragrant South Asian fare.

San Francisco has permission to build a sea wall along a portion of Ocean Beach to protect some of the city’s critical infrastructure from erosion, but some people, including surfers, aren’t on board.

The city wants to build the sea wall to protect sewage infrastructure at Ocean Beach between the Westside Pump Station and the Oceanside Water Pollution Control Plant.

The approved sea wall will begin at Sloat Boulevard and the Great Highway and extend 3,300 feet south. Along that route, beach erosion has felled some pipes. Portions of the Great Highway have also been narrowed.

The intention of the sea wall is to protect a 14-foot diameter tunnel that’s used to store wastewater and stormwater when the water pollution plant is at capacity.

If it is compromised by erosion, untreated effluent could head out to the ocean during a storm.

Among the most organized in opposition to the sea wall is the Surfrider Foundation. The group argues a sea wall will actually contribute to erosion because, it contends, walls magnify the impact of waves and help wash out sand faster.

“We’re really disappointed,” Surfrider Foundation policy coordinator Mandy Sackett said. “We think this was a really complex situation, but it’s not going to get easier as time goes on. We have to make hard calls and move infrastructure out of harm’s way.”

Sackett said the $175 million earmarked for the sea wall would be better spent to help move the storage tunnel further inland to protect it from erosion.

The coastal commission’s permission does come with some caveats. It’s limited to 25 years, and the commission will check on how it’s working every five years.