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Facing a multimillion-dollar to-do list, city officials ponder the fairest way to cover the cost of clean water.
KYLE GREEN | The Roanoke Times
When a Grandin Court homeowner contacted the city because she was worried about water damage to her property, Roanoke civil engineer Josephus Johnson-Koroma was dispatched to the Corbieshaw Road property. Here he examines the path of an 8-inch pipe that carries water from a small spring nearby.
KYLE GREEN | The Roanoke Times
Johnson-Koroma peers into a manhole in front of a Grandin Court property. Because the mortar and bricks inside were still intact, he determined that water couldn’t have been seeping into the property owner’s yard.
Sunday, June 9, 2013
It had been several days since the last rain, but standing by the drain grate halfway down the hill in the Grandin Court neighborhood, the burbling water below was easy to hear.
The curb behind the grate had over the years been shoved up a couple of inches.
With those two clues, and the homeowner's report that her basement had flooded a few years back, Josephus Johnson-Koroma, one of Roanoke's civil engineers, had to figure out if he had yet another rainwater drainage problem to add to the city's multimillion-dollar to-do list.
Lying at the bottom of a mountainous bowl, Roanoke has a major problem keeping storms from causing floods. It isn't made easier by the fact that many of the aging drain pipes buried under hundreds of miles of city streets are less than half the minimum size the city now installs on even its smallest projects. Nor by the prospect that federal and state environmental regulators are about to start setting tougher standards for the rain water flowing out of those pipes and into the city's 13 creeks and rivers.
The bill to solve Roanoke's drainage woes comes to nearly $74 million. This year, the city has $2.2 million available to chip away at the problem.
That's why city officials plan to ask the Roanoke City Council to consider establishing a storm water utility.
"We know we have to do something to reduce flooding and to improve water quality," said City Manager Chris Morrill.
"We know it is going to cost considerable dollars in capital and maintenance. The question is: What's the fairest way to do it?" he said. "The bottom line is, we want our rivers and streams to be clean."
What city officials plan to propose this summer is a user fee based on the extent to which buildings and paving on a piece of property block rain from simply seeping into the ground and flowing slowly to creeks or rivers. When rainwater moves that way, it is less likely to flood, while the soil acts as a filter to absorb pollutants.
City officials had first suggested charging all single-family homes a $3 per month fee, with businesses paying multiples of that depending on how much of their property exceeded the average 1,920 square feet of impervious surface on residential lots.
Now, though, officials are moving toward simply charging a set amount - still to be determined - for each 500 square feet of impervious surface, said City Engineer Phil Schirmer.
"If you have a little house, you pay for a little house; if you have a big house, you pay for a big house and if you have a big parking lot, you pay for a big parking lot," he said.
Every property owner would be covered - including the city itself. There would be credits and incentives to hold down fees for property owners who take steps to reduce runoff.
The idea is to raise about $4 million a year, with about $3 million slated for long-needed construction projects, $500,000 for maintenance work and $500,000 for efforts to meet the tougher new water quality standards that are coming.
Using that money as a reliable stream of income means the city could afford to borrow the big bucks needed to step up the pace of fixing all the drainage problems on its list.
Some of the biggest projects include:
But there are plenty of neighborhood problems, too: 138 at last count, with an estimated cost of nearly $25 million to fix. Some have been on the list for years.
On the 1500 block of Cove Road, Richard Taylor's basement regularly floods, since the layout of his neighborhood, built in the early 1950s, means his sump pump has no place to drain. A heavy rain means his back yard floods. He complained to the city 13 years ago, and while he figured they had forgotten him, the city has figured out a $254,000 fix, running 750 feet of drain pipe to his sump pump. His problem now ranks 20th on the neighborhood list.
"It'd be nice to get it fixed," he said.
Johnson-Koroma was in Grandin Court to see if there should be a 139th entry on that list.
The water is flowing because there is a spring across the way - years ago, it was the water source for hundreds of homes in the area, or so the homeowner with the uneven curb and the worries about flooding told Johnson-Koroma.
When she first moved to the area, three decades ago, she'd see the spring bubbling away on what was then a vacant lot. When a developer put up some homes, the city had a drain installed. A small pipe ran across the street to a manhole and then an 8-inch pipe went from there down the street.
The homeowner pointed to the heaved-up curb and the displaced steps on her walk and said she was worried the water wasn't flowing where it should.
Johnson-Koroma leaned over, then, as if doing a push-up, stretched to peer through the grate into the manhole.
"The mortar's still there, the bricks aren't coming out," he told her. That meant that water shouldn't be seeping into her yard.
He nodded at the pile of leaves and dirt on the uphill side of the grate, and at the flat-tired car parked there. The weight of the car, if it had been left there for years, was enough to shift some earth, he said, and it kept street sweepers from reaching the leaves. If they eventually got down the grate, they could clog the pipe, he said.
The neighbor whose lot contains the spring came by. She told Johnson-Koroma that while she used to see water bubbling from the spring when it rained, she hadn't noticed that lately. She asked if a change in the water table or in the way the spring was draining explained the shifting curb.
"Water tables go up and down," Johnson-Koroma said. It's a question of how much rain there's been.
"This is just a natural channel, and there's water underground from the spring. We can't change that," he said.
Johnson-Koroma kicked at the grate. He didn't like it, he would say later. The problem is that it lets water from farther up the hill into the pipe that's supposed to drain the spring.
When he traced the pipe down to the bottom of the hill, he found two other clues. First, a steady stream of water was flowing - the spring was draining. Second, that the pipe is just 8 inches in diameter.
On this bone-dry day, the spring's flow filled the bottom fifth of the pipe. In a heavy enough rain, with runoff flowing into the grate, that 8-inch diameter might not be enough.
"We use 15 inches as a minimum now, mostly 18 inches," he said. Mind, there are still plenty of old 8-inch pipes around the city, in places where more water flows than from the Grandin Court spring. Replacing them accounts for a healthy part of the city's drainage needs.
The spring, though, would not become problem No. 139 on the neighborhood drainage issues list.
Within 90 minutes, Johnson-Koroma had put together a fix.
He sat down with Street Maintenance Supervisor Mike Jones and outlined what he'd found: the shifted curb, the grate, the leaves and the flowing water at the bottom of the hill.
Johnson-Koroma and Jones agreed the grate should be replaced with a solid manhole cover, to keep any extra water from flowing into the 8-inch pipe. They'd ask the property owner to move her old car - a cleanly swept gutter and curb on the fairly steeply sloping street should keep water from even the heaviest storms flowing.
The city would also install 20 feet of new curb and gutter, where the curb had heaved up, to smooth the path for any runoff.
"Getting all of this done will help," Johnson-Koroma said.
If only, city manager Morrill said later, the rest of the drainage to-do list was as easy.
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