From the Charlotte Observer (Owners seek credit for Green Space):
Charlotte homeowners with more than 5,000 square feet of impervious surfaces would see their annual fee increase from about $96 to more than $200. ...
City Councilman Michael Barnes said he has received e-mails from constituents concerned that the lawns and trees they take care of wouldn't be factored into the new equation. “Bigger homes are typically on bigger lots with lawns,” he said. “There should be some accounting for that.”
Charlotte and county officials say they don't take the green spaces into account because it would take too long and too much money to tabulate and keep up with over time.
“It's been talked about, but technology-wise, we're not there yet. It might happen in the future, but it's not happening today,” said Joe Hecksher, business manager for Charlotte Storm Water Services.
He said homeowners who build retaining ponds or rain gardens or take other measures to capture significant amounts of rain can apply for credits. But just having a big lawn or a couple rain barrels probably wouldn't cut it, he said.
If you can gather data on square feet of impervious surfaces, how much harder would it be to divide by lot size? On the other hand, how much adjustment in annual fees are likely due to changes in lot size. Reducing the annual fee from $200 to $180 doesn't seem like that big of a deal (especially considering bigger homes are often owned by richer people and the marginal utility of $1 falls with income [in theory]).