Edisto numbers

1,689 million: Average gallons-per-day flow in the Edisto River.

639,800: Average gallons of treated wastewater discharged into the river daily in 2013.

110.5 million: Gallons per day permitted to be drained into another river basin.

100 million: Gallons per day Charleston Water System is permitted to withdraw.

30-35 million: Average gallons per day CWS withdraws.

S.C. Department of Natural Resources, S.C. Department of Health and Environmental Control, Charleston Water System.

The serene black willow bends of the Edisto River seem to sit out in the pines, off to one side of Lowcountry metro growth. But without this river, the conservation movement that is now helping to preserve the "green" natural environs of the entire area might not have taken place.

Now the "backwaters" Edisto is starting to see development pressure. Its future could determine in a big way how green the greater Charleston area remains.

Just as conservation, agriculture and business interests seem to be finding an equilibrium along the river near Charleston, conflicts are flaring upstream. More of its waters are being grabbed, and a small-scale "water wars" is underway. Residential developers and even industries are eyeing once-remote river environs. Pollution is becoming an issue.

The Edisto feeds two-thirds of the water flowing into the vast Ashepoo, Combahee Edisto (ACE) Basin delta south of Charleston. The unprecedented, private-public conservation begun by landowners in that delta has blossomed into a "greenbelt" of three-quarters of a million acres around the metro area, helping preserve the riverine landscape that is the Lowcountry.

"You can't take for granted that you can have a place like the ACE Basin if you let the north and south forks of the Edisto be transferred from ecological environs to spigots for industrial production," said Tim Rogers, Friends of the Edisto president.

"There's got to be a balance struck between business and natural development," said Lewis Gossett, South Carolina Manufacturers Alliance president.

Water war

The conflicts cropping up along the rural upstream Edisto are over "urban" issues such as wastewater effluent loading and water withdrawals.

Two years ago the Batesburg-Leesville wastewater treatment plant was fought to a standstill by conservationists after proposing a major increase of its treatment capacity and effluent discharge into the relatively shallow headwaters of the Edisto, in order to treat sewage from other plants in the Midlands west of Columbia as a revenue producer. Now the plant is eyeing another big expansion for a regional industrial park.

So far, the discharge of treated wastewater makes up only a tiny fraction of the river flow. But the Batesburg-Leesville plant is among any number of treatment facilities along the river - including in Orangeburg County and Dorchester County's plant in St. George farther downstream - that have recently expanded and/or want to expand capacity to deal with growth.

Meanwhile, water withdrawals have become a budding intrastate version of the "water war" that raged recently between South and North Carolina over the Catawba River. A water utility in North Carolina proposed to pull water from the Catawba and use it in a place that would drain to another river, denying downstream Catawba users some of the river flow. Those users include most people who drink water in the Charleston area.

A recent Edisto controversy surrounding the Walther potato farm in Windsor, south of Columbia, has been settled - for now - with both sides compromising on a permit sought by the farm to withdraw some 800 million gallons per month for irrigation. But the legal wrangling and hand-wringing on both sides show that a newly negotiated "stakeholders" state policy for deciding withdrawals isn't going to decide anything.

Rogers, of Friends of the Edisto, said his group did not get the limits it wanted. Gary Spires, of the S.C. Farm Bureau, called it a good law that needs time to work before adjusting it, if needed.

Meanwhile, more than 110 million gallons of water each day are currently permitted to be drawn from the river and end up draining to another river basin - the nub of the Catawba dispute. That's only about 7 percent of the flow, and not all of it is actually being pulled. The biggest permit holder is the Charleston Water System, which is taking only about one-third of its 100 million gallons-per-day permit, to supply the KapStone packaging plant and to back up the main water supply along the Cooper River, according to company spokeswoman Jenny Craft.

But the bottom line is the Edisto is being tapped now, users are looking for more, and the pressures will build as the river region grows.

Tawny gold

In the late 20th century, the industrialized Cooper River was the focus of Lowcountry pollution concerns. In the 2000s, the Ashley River plantation district was the focus of development concerns. All the while, the Edisto swept the southern border of Dorchester and Charleston counties for 70 miles into the plantation lands of the ACE Basin.

Maybe the longest free-flowing blackwater in the world, it ran for more than 200 miles overall, largely through an infrastructure-poor area without much development and even recreational pressure.

For generations, as other waterways developed, the Edisto remained largely a fishing cabin haunt of longtime country families. The willows dipping their heads from the river banks, the sun turning the autumn cypress tawny gold - it's been a small-boaters' paradise, the hole where kids learn to swim, the rollicky float where teens tubed in the summer, the marsh where hunting is keenest, the bluffs of remote fish camps where men sneak off when redbreast are biting.

The serenity muted a number of emerging problems. The river is shallow enough that the flow near Givhans State Park outside Ridgeville dried during the recent drought to runs of little more than wading depth. In other words, at times there isn't a lot a lot of water to go around.

As agriculture and wastewater treatment demanded more water, timbering took away filtering buffers. Landfills were built along tributaries.

The S.C. Department of Health and Environmental Control has long had fish consumption guidelines in place for the Edisto, as well as other state rivers, because of mercury and other pollution.

SCE&G's coal-fired power plant in Canadys released toxins such as mercury. Its coal ash pit along the river bank breached on at least one occasion; arsenic plumed underground at unsafe levels. The plant has been maybe the largest heavy industry along the river.

As early as the 1990s, a stakeholders report through S.C. Department of Natural Resources pointed to the troubles and called for a cooperative stewardship and regulatory effort among local governments to manage the competing interests on the river; little has been acted on from the report's recommendations.

"It was acknowledged as being useful, but in reality I don't think local governments used it very much," said Bill Marshall, S.C. Department of Natural Resources program manager. The state's newly passed Surface Water Withdrawal act that failed to resolve the concerns with the Walther farm irrigation was passed in response to the North Carolina water war.

Meanwhile, a National Estuarine Research Reserve System environmental analysis of the ACE Basin cites potential problems in the delta, with contaminant-loading including nutrients and other pollution from fertilizer and treatment effluent, as well as sedimentation from timbered or developed river buffers.

In the early 2000s, MeadWestvaco and other timber interests began selling large tracts in the river region pineland, in the midst of the housing boom. Meanwhile, river region economic groups began pushing harder for sewer and other infrastructure to lure development. That boom is back on.

Co-exist?

Farmers who once were the primary industry along the Edisto now find themselves fighting for their share of the water. During the Walther farm controversy, the South Carolina Farm Bureau labeled conservationists as radicals costing the farm economy jobs.

"We just feel that agriculture needs to be treated differently (than other users)," said David Winkles, Farm Bureau president. "Agriculture and the rest of the interests, we can co-exist without harming each other," but "use the resource for the products the consumer needs and wants."

Gossett, of the manufacturers alliance, said the once infrastructure-poor Edisto region is becoming more attractive to industrial development.

"Orangeburg County has some locations. Colleton County has all kinds of potential for industrial development. And you want to see that. You want to see them get those high-paying jobs."

In the Lowcountry, the equilibrium between business and natural development is still a little teetery. The Canadys plant is shutting down. SCE&G is removing wet ash and sealing its riverside coal ash pits. But the company continues to seek permits for an 80-acre landfill to stack dry coal ash behind the pits. Residents worry that such a landfill would take the pollutant-laced ash from other plants, further threatening the river and rural environment. An SCE&G spokesman said the company will not do that.

MeadWestvaco pulled back from selling acreage along the Edisto. In a move hailed by conservationists, the company and its new partner, Plum Creek, are refining plans for the East Edisto "green" development of some 70,000 acres between Summerville and the river just upstream of the ACE Basin. Some 16 miles of riverfront on both banks have been placed under conservation easement between U.S. 17 and Givhans Ferry State Park.

Above Givhans Ferry, sand mines - for construction - have begun to pock the riverland. Industries and suburban-style developments are popping up and dense Summerville development is creeping closer.

"How to accommodate (uses) with maintaining a healthy river - they're not black and white questions and answers, but they're fundamental and they need to be dealt with," said Rogers, of Friends of the Edisto. "What really needs to happen is decision-makers in the state need to make these decisions."

Maybe the most curious and heartening aspect of the conflicts, though, is that the competing interests tend to share a strong emotional bond with a river they consider unique. Spires, of the Farm Bureau, talks about how abusing the Edisto would be counter-productive to the farmers who live and rely on it. Gossett, of the manufacturers association, has long hunted and fished the river.

"The Edisto is not really in danger of being 'stacked up along the banks.' I believe in finding a balance. I don't want to take away the scenic ecosystem value. I like to think 50 years from now my grandchildren will be on the same Edisto River I am now," he said.

Reach Bo Petersen at 937-5744.