Mike DeSimoni’s gamble that affluent families will want to buy high-end riverfront condos in downtown Napa appears to be paying off.

Despite an ailing housing market, the first 10 residences in the Riverfront, a mixed-use project at Main and Third streets, sold out the day they were put on the market.

Buyers put down $10,000 deposits last week for units selling for between $695,000 and $1.67 million, with occupancy set for early 2009, said Michael Carreno, president of sales company the Reiser Group.

“People believe that living downtown is probably the way of the future,” said DeSimoni, whose family company, Channel Properties, is building two blocks of stores, restaurants, offices and condos. “I think they will all sell. It’s the uniqueness of the location.”

“If you’re looking for downtown, urban-style living, riverfront property, walking distance to restaurants and shops in Napa, where else are they going to go?” Carreno said.

“It’s incredible,” said Cassandra Walker, the city’s economic development manager. “It shows there is a market for downtown residential development, even in difficult times.”

“It clearly speaks to the value that people place on downtown and the river today and what’s in the future,” said Craig Smith, executive director of the Napa Downtown Association.

With its prominent river location, the Riverfront occupies pride of place in Napa’s fast-developing downtown, next to flood control improvements, including a pedestrian promenade and a redesigned Veteran’s Memorial Park. Plans are under way for more than $500 million in private development within walking distance of the Riverfront, including new hotels and office-retail projects.

But given the state of real estate today, pricing the first condos in an untested downtown market was tough, Carreno said. Had the project gone to market two years ago, residences might have sold for 10 to 15 percent more, he said.

The first 10 buyers include several who already live in Napa, several more who have second homes here, with the rest frequent Napa Valley visitors who like the wine country lifestyle, Carreno said.

One buyer is Bob Brosamer, owner of R&L Brosamer Inc., the general contractor who built the promenade and flood wall in front of the Riverfront for the U.S. Army Corps of Engineers.

“We’re excited by the vision that both Mike and Harry Price (developer of Napa Mill next door) have for downtown,” Brosamer said. He reported paying “a lot” for a 1,700-square-foot, two-level, two-bedroom unit with river views.

“We’ll see the river. At high tide it looks great. At low tide it doesn’t look so great,” he said.

With its restaurants and spiffy new waterfront, downtown is “nice now, but it will do nothing but get better,” Brosamer said. He intends to use his condo as a weekend home and loan it out to friends.

“As I get a bit older, I could see myself slowing down and staying there three-four days a week,” he said.

The Riverfront will have 50 condos centered on a landscaped courtyard on the top two floors at the south end of the project. Residents will park in a two-story underground garage.

The next batch of 10 condos will be offered for sale in October. The Riverfront will open a full-time sales office in Alexandria Square, the commercial building that Channel Properties owns at Second and Brown streets.

Pricing is being established for the remaining 40 condos, which will range from 947 square feet to 2,123 square feet, Carreno said. Some could sell for under $500,000, he said.

Sales materials promote luxury living, with condos having hardwood floors, granite slab counter tops and high-end appliances. Buyers are able to customize amenities, Carreno said.

Napa Mayor Jill Techel said the city is promoting mixed-use development downtown, with the goal of creating a more lively city center.

“When we approved (Riverfront), we knew it would be more expensive,” Techel said. Future projects located a block or two from the river will be more affordably priced, she predicted.

Channel Properties said Morgan Stanley had leased 8,600 square feet of the project’s 30,000 square feet of office space. Negotiations are under way with “major restaurateurs” for portions of the project’s 40,000 square feet of retail.

More information on condo sales is available at riverfrontofnapa.com or by calling 252-5463. Commercial leasing information is at mspsinc.com.