A $3.5 billion, 600-mile natural-gas pipeline system that will stretch from Alabama into Florida is still in the planning stages, but homeowners near the Ichetucknee and Santa Fe rivers are concerned because the routes being proposed might run through their neighborhoods. Florida Power & Light selected Sabal Trail Transmission to construct a pipeline that will wind from southwest Alabama through Georgia to a Central Florida hub, from which point another company will build a pipeline that runs into Martin County. The pipeline system should be operational by May 2017, FPL spokeswoman Sarah Gatewood said. FPL selected Sabal Trail Transmission and the second company, Florida Southeast Connection, in late July, but it received the Florida Public Service Commission’s approval of the prudence of its chosen contracts Thursday. Florida Southeast Connection is a subsidiary of NextEra Energy, FPL’s parent company. Sabal isn’t a subsidiary of NextEra, although NextEra did invest in Sabal’s pipeline project, Gatewood said. FPL’s long-term natural gas contracts with Sabal and Florida Southeast Connection are projected to save as much as $450 million compared with the company’s other options, according to a news release. Nearly 68 percent of electricity in Florida relies on natural gas, Gatewood said. FPL needs more natural gas in South Florida, which is why the new pipeline system will trail down to its Martin County plant. An even bigger reason for building a new pipeline system, however, is that there are only two major pipelines that deliver natural gas to Central and South Florida at present, both of which are nearing capacity. Once the new system is built, the three pipelines will be interconnected to improve the overall system’s reliability, Gatewood said. Sabal recently completed a series of informational meetings with landowners along its proposed pipeline corridor, Sabal spokeswoman Andrea Grover said. It will have another round of community meetings in December. The company began conducting surveys along the corridor in September. The survey work analyzes the route’s potential environmental impact among other issues. The proposed route through North Florida was originally going to follow an overhead power line in the Columbia County area and cross the Ichetucknee River, Grover said. Now it will cross from Suwannee County into Gilchrist County by running underneath the bed of the Santa Fe River. It will also run through about four miles of land in the southwest corner of Alachua County. Sabal’s proposed route isn’t final and is still under review, Grover said. The company plans to submit a formal application to the Federal Energy Regulatory Commission for approval next year, which will include its preferred route as well as alternatives.