Christina O'Haver, The Union Democrat

Construction for high-speed Internet in Tuolumne and Calaveras counties could be coming to an end this spring, after the area's rocky terrain put the federal stimulus project several months behind schedule.

Work is about 82 percent completed in Calaveras County and 50 percent completed in Tuolumne County, according to Mike Stewart, the director of marketing for the Central Valley Independent Network.

Construction is part of the "Central Valley Next-Generation Broadband Infrastructure Project," which aims to improve high-speed Internet access in underserved and rural areas.

A collaborative effort between the network and the Corporation for Education Network Initiatives in California, the project encompasses 18 Central California counties.

Stewart said the entire project is about 67 percent complete, and construction is expected to wrap up in April.

The network recently broke ground in Nevada County and expects to begin construction in the final county, El Dorado, in about two weeks, according to Stewart.

Planners initially projected a completion date of August 2012, but construction was delayed when workers encountered rocks underground in mountainous counties instead of the soft soil found in Central Valley counties, Stewart said.

"It's been slower than I think they anticipated, but they've been out there working diligently throughout the winter," Deputy Tuolumne County Administrator Daniel Richardson said.

Stewart said workers had to alter construction methods in many areas, switching from open trenching to directional boring. The latter requires workers to drill small holes in pavement rather than cut a large trench, and create a horizontal underground tunnel.

Conduit - plastic piping that protects and routes electrical wires - is then fed through the holes and into the tunnel.

According to Stewart, about 5,000 feet of conduit can be installed per day when there is soft soil to work with, but as little as 300 feet can be placed when the terrain is rocky.

After conduit is in place, the fiber-optic wire is blown into one of four microducts using a high-powered compression system known as fiber-jetting, Stewart said.

The Central Valley Independent Network can feed more fiber-optic cables into the other three microducts in the future or sell the microducts to other service providers.

The Internet project is funded by the American Recovery and Reinvestment Act of 2009, which provided $7.2 billion in stimulus money for projects to increase high-speed Internet access, particularly in rural or underserved areas.

It will increase Internet speeds for public schools and community colleges as well as provide more reliable service for public safety institutions and hospitals.

Stewart said it could also be distributed wirelessly to homes.

"We have been broadband-starved for too long, so we eagerly anticipate them lighting up the fiber and helping us move into the 21st century," Richardson said.