apologies to everyone else for using this public forum to make connections...

http://www.salon.com/news/feature/2007/10/01/parking/index1.html

Like I said earlier, you have to get to the zoning boards to change this stuff. I'd bet that the Walmarts and Home Depots of the world don't like having to buy, build, maintain, light, clean, police and pay property taxes on such huge parking lots. Their planners have their own idea of how big a parking lot should be and it's probably much different than what they're required to build in a lot of places.

You want to really see disgusting parking lots? Go down to Florida to western Palm Beach county where my in-laws live and check out one of the new Super Targets that exist every five miles. They pave over acres and acres of wooded swamp lands to build parking lots that are 90 percent empty almost every day.

Government requirement to install parking spaces does constitute a subsidy. Even if the subsidy is ultimately paid for by the users of the facility, such regulations nonetheless serve to artificially inflate the supply, and thus the quantity demanded, of parking spaces and vehicle utilization.

Imagine, for a moment, that all shopping malls were required to provide a free orange on request with any purchase. Would people stop shopping at malls? No. Would prices increase? Yes, but only marginally -- oranges are not that expensive. Would the number of oranges produced, bought, and distributed for this purpose increase? Innumerably. Would purchase of other substitute food products, like tangerines and clementines decrease? For sure. Runoff and other agricultural issues aside, the only difference between the current regulatory environment and this hypothetical one is that using a parking space has considerably greater market externalities.

Sadly, it looks like we won't be installing a green roof; our building isn't strong enough to support one. If anyone knows of a way to minimize runoff without one, please let me know. We'll probably be installing photoelectric sheeting, though.

As to how to do that, I've only heard of methods like the one Mitch is suggesting. It wouldn't have to be limited to commercial property. Just offer tax abatements for green roofs and lawns.

There are still problems with estimated versus actual readings (my current bills are based on one of each), but in general the system seems more straightforward.

Hilary: Are you suggesting a metering system for soil-line discharges into the main flow of the sewer? If so, how would this work? I mean, how would actual use be monitored so it could be charged for on a more objective basis? Thanks.

For Building A--which is smaller and has fewer occupants--the charge for 90 days of water use comes to $70; for sewer, $111.

For Building B--which is larger and has a greater number of occupants--90 days' water use comes to $143; sewer, $228.

I hope you find these numbers useful.

And you're right about the parking lots costing the city money -- in two-thirds of the city the water collected in those lots goes into combined sewers and when it's not raining gets treated in a sewage treatment plant. When it is raining the parking lot water adds to the overflows from combined sewers and increases the amount of raw sewage that gets dumped into the harbor. Also, the litter that gets washed down the drain in those parking lots often goes into the sewer system and then out into the harbor and then onto a beach somewhere. Or into a birds gullet. Ninety percent of the litter floating in the harbor started out as street litter somewhere.

NYC creates a problem with the way it bills for water. We get bills for water consumption and sewerage, but only the water use is actually metered and then doubled, on the assumption that they're equal. This means someone who irrigates a garden, which is a shared resource, pays a lot. The parking lot owner, who costs the city plenty (even federal fines), pays nothing.

The lots can also be made from porous materials. There are such things are porous asphalt and porous concrete that allow stormwater to drain right through, reducing pollution runoff and flooding concerns. I think NYC is going to try some of those out as part of its Jamaica Bay watershed protection plan.

I don't see how this is really a "free parking" problem though. We're talking about private parking lots, no matter how vast they are, created on private property and maintained by private interests. People who shop at Walmart are probably aware that the price they pay in the store includes the cost of maintaining the parking lot outside.

Current parking requirements were originally based on quantitative studies of how much parking demand is generated by different land uses. Because we followed these quantitative standards rather than building livable neighborhoods, we are now forced to do quantitative studies of how much damage the parking is doing.