A mostly well-behaved crowd moves down Del Playa Drive in Isla Vista on Saturday during “Deltopia,” the community’s annual unsanctioned street party marking the beginning of spring. Officials said crowds, arrests and medical calls were down again this year. (Zack Warburg / Noozhawk photo)

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Thousands of students rang in the spring season in Isla Vista on Saturday with “Deltopia,” the college community’s massive annual unsanctioned street party.

With a relatively paltry 3,500 attendees, the sun- and alcohol-fueled event went off much like last year’s, with few arrests and citations, according to Santa Barbara County Sheriff’s Department spokeswoman Kelly Hoover.

Officials noted there was a clearly apparent commitment to keeping the party local.

“The vibe out here is festive, people are enjoying the beautiful day, having a great time,” Hoover said late Saturday afternoon.

“We’re very pleased with the cooperation from students. The No. 1 reason why this event was so successful was the fact that the students did not encourage out-of-towners to attend, did not advertise on social media, or invite and hype the event.”

The low numbers continue the 2016–2017 school year’s marked improvement in resident behavior, as judged by arrests and citations.

By late Saturday, 45 arrests had been made, according to Hoover — three of which were felonies. Forty-eight citations had been handed out, with more likely to come later in the night, and 10 people had been taken to local hospitals as of 8 p.m.

Last year’s iteration, by comparison, witnessed 10,000 attendees and more than 100 arrests and 140 citations by 11 p.m.

Enjoying a sunny spring day, young revelers walk past a house party in Isla Vista on Saturday during the annual Deltopia celebration.

Enjoying a sunny spring day, young revelers walk past a house party in Isla Vista on Saturday during the annual Deltopia celebration. (Zack Warburg / Noozhawk photo)

Deltopia, which typically runs from midday into the evening the first Saturday of UC Santa Barbara’s spring quarter, blurs the lines between individual house parties and a town-wide festival.

Under ideal weather conditions, throngs of predominantly UC Santa Barbara and Santa Barbara City College students took to Del Playa Drive or held private parties.

Del Playa — the heart of the I.V. party scene — was once again transformed into a bustling pedestrian corridor where passersby sightsee as much as head to and from parties.

As in previous years, law enforcement maintained an increased presence, with the Sheriff’s Department, University of California police, California Highway Patrol, the county Fire Department, and the sheriff’s Search and Rescue Team out patrolling.

But unlike most of Deltopia’s history, the augmented police force had relatively little to keep them busy aside from patrols and keeping an eye out.

“We’ve said ‘hi’ to a lot of people,” one UC police officer said in the early afternoon. “It’s been calm; everyone’s been very well behaved.”

“There have been a few arrests, a few public-intoxication (citations), but for the most part it’s been OK,” a sheriff’s deputy said.

Bubbles add to the fun Saturday during the Deltopia celebration in Isla Vista.

Bubbles add to the fun Saturday during the Deltopia celebration in Isla Vista. (Zack Warburg / Noozhawk photo)

Hoover noted the positive trend.

“This is the second Deltopia in a row, and the second Halloween in a row, where we’ve seen a major decrease in attendance, and as a result, the number of citations and arrests and medical transports as well,” she said.

Barricades were erected to prevent nonemergency vehicle traffic from accessing the 6500 through 6700 blocks of Del Playa and Sabado Tarde and Trigo roads, and UCSB students who purchased permits could park in one of several university parking lots.

Additionally, I.V.’s beaches were closed to the public to ensure that partying didn’t spill out on the sand or in the ocean.

Like 2015’s Deltopia, the relative tameness of this year’s event resulted from a number of efforts, including a greater commitment among residents to not invite out-of-town friends and shun the out-of-towners who did show up at their doors.

Parties that a few years ago would have overflowed into a crowded street remained well within their property lines, shunning the unwieldy size that leaves local authorities and stakeholders on edge.

A party is in full swing Saturday during the Deltopia celebration in Isla Vista.

A party is in full swing Saturday during the Deltopia celebration in Isla Vista. (Zack Warburg / Noozhawk photo)

The afternoon crowds peaked at around 3 p.m., according to Hoover, and dropped to only 500 by 7:30 p.m. Once the festival ordinance went into effect at 6 p.m. — where no music could be audible outside a property — I.V. became unusually quiet.

UCSB further diluted the number of attendees by reprising a month-long social media campaign — warning out-of-towners of the legal and financial repercussions of attending, and urging students to keep it local and safe. The university also reached out to colleges from San Luis Obispo to San Diego and east to Bakersfield.

UCSB drew additional students onto campus with a host of weekend activities, including Saturday night’s second-annual “Warm Up” concert in the Events Center, headlined by indie rock band Grouplove.

Mingling with the crowds was UCIV, a UCSB Associated Students organization that handed out to revelers everything from water to condoms, and warned residences of the I.V.-exclusive festival ordinance.

The evening remnants of Deltopia went dark as well as quiet when an underground electrical fire on Embarcadero del Mar forced a shutdown of much of eastern Isla Vista’s electrical grid.

Noozhawk staff writer Sam Goldman can be reached at sgoldman@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.

Traffic was blocked off on Del Playa Drive and other popular party streets in Isla Vista on Saturday.

Traffic was blocked off on Del Playa Drive and other popular party streets in Isla Vista on Saturday. (Sam Goldman / Noozhawk photo)