In 1991 most of the Malibu land grant was incorporated as a city to allow local control of the area (as cities under California law, they are not subject to the same level of county government oversight). Prior to achieving municipal status, the local residents had fought several county-proposed developments, including an offshore freeway, a nuclear power plant, and several plans to replace septic tanks with sewer lines to protect the ocean from seepage that pollutes the marine environment. The incorporation drive gained impetus in 1986, when the Los Angeles County Board of Supervisors approved plans for a regional sewer that would have been large enough to serve 400,000 people in the western Santa Monica Mountains. Residents were incensed that they would be assessed taxes and fees to pay for the sewer project, and feared that the Pacific Coast Highway would need to be widened into a freeway to accommodate growth that they did not want. The supervisors fought the incorporation drive and prevented the residents from voting, a decision that was overturned in the courts.