Many Hilton Head Island residents' water and sewer rates could be increased as utilities try to cope with higher demand and intrusion of saltwater into the island's main water supply.
Homeowners in Palmetto Dunes, Leamington, Shelter Cove, Yacht Cove and Chimney Cove probably will pay as much as $6.30 more a month under a rate increase proposed by the Broad Creek Public Service District.
Owners of single-family homes would pay $1.75 instead of $1.45 per 1,000 gallons of water used on the first 21,000 gallons, or about $37 a month. Owners of undeveloped home lots within the Broad Creek district would pay $30 more a year for water and sewer service.
The "availability fee" -- charged to properties that have water and sewer service available, but are not connected to the systems -- would increase from $270 a year to $300. The increase would help cover $3 million spent during the last five years to upgrade small sewer lines and replace outdated sewage tanks, general manager Russell Hildebrand said.
"That rate has not changed for the last 15 years or so, and everyone in the district should share in the cost of providing that infrastructure," Hildebrand said. "Otherwise, they're getting a free ride."
Broad Creek, like other water and sewer utilities on the island, also has seen its costs rise as it searches for new sources of water to replace those that have been lost.
Studies shows the rate of saltwater entering the freshwater Upper Floridan Aquifer, the primary source of the island's drinking water, has increased because of demand from coastal communities in South Carolina and Georgia. Salt water has been advancing about 350 feet a year into the aquifer from Port Royal Sound through the north- and mid-island areas.
That has forced Broad Creek and other public service districts to buy more water pumped from the Savannah River by the Beaufort-Jasper Water & Sewer Authority.
Unlike South Island and Hilton Head public service districts, Broad Creek has yet to lose a well to saltwater, but modeling suggests that won't be the case forever, Hildebrand said.
"The studies over the last 10 years show the island -- without some major reduction in water use by Savannah -- will lose all of its wells within 25 years," Hildebrand said.
Hilton Head's three public service districts have been working together to tap other sources and conserve as much water as possible to ensure the island maintains a supply of fresh water.
South Island and Hilton Head districts previously raised their rates or taxes to build recovery wells that store water in an underground aquifer during winter months, when demand is lower. Water can be withdrawn from the well during the summer, when demand rises.
South Island PSD also plans to improve its reverse-osmosis treatment plant, which draws water from the much deeper Cretaceous Aquifer, and upgrade its water distribution system.
Hilton Head PSD has a similar plant that opened in 2009 and draws water from the 600-foot-deep Middle Floridan Aquifer. Broad Creek receives some of its water from that plant, and might build its own recovery well, Hildebrand said.
All three districts also use reclaimed, treated wastewater to irrigate island golf courses that would otherwise use drinkable water.
"We're trying to get as much life out of these Upper Floridan wells as we can," Hilton Head PSD spokesman Pete Nardi said. "These other supplies allow us to relax our usage."