Holy pumpkins, it's almost time to turn the rain barrel cylinder from "collect" to "bypass." Such a simple act, yet so difficult -- another acquiescence to the cold.

A rain barrel should spend the winter drained of water. By switching to bypass, you prevent it from receiving water from gutters via the downspout.

The environmental reason for owning a rain barrel is to keep water out of the storm sewer, so the good steward will monitor winter weather and collect and drain rain during rainy spells. But a rain barrel is not just a green machine. You can save money, and the savings pays for the cost of the rain barrel in several years.

Two summers ago, I used water from my rain barrel not only on my garden but also to flush the toilet and wash my hair almost every day. It was a little extra effort, which I perversely enjoyed: The sewer authority got $50 less from me between May and September.

Rain barrels also save the public on the cost of water treatment and sewage cleanup. Some people like them so much they have two, three and four hooked together.

I ordered my RiverSafe barrel, made by Canadian company Riversides, in 2005 after attending a meeting at the Nine Mile Run Watershed Association. The organization had contracted with Herbert Dreiseitl, a renowned urban planner who specializes in diverting stormwater by way of landscaping and sculpture.

He presented ideas for artistic water diversion and told us, "Remember, the key is to reduce the stormwater that gets in the sewage system. We want water to soak in the way it did before we showed up on the earth."

Without rain barrels, downspouts feed directly into pipes that connect to storm sewers, or they empty onto alleys, sidewalks and streets. Pavement lets stormwater rush unimpeded, and it doesn't take much of a storm to force sewage up into the flow that runs into streams. A 133-gallon rain barrel can fill in five to 10 minutes during heavy downpours, which is why I keep mine attached to a hose with the nozzle open all summer.

Nine Mile Run was a cesspool before the watershed association, the city and the U.S. Army Corps of Engineers initiated the largest urban stream restoration project in the nation in 2003. It cost $7.7 million to clean and restore the stream, and the rain barrel project that grew out of that work now counts 1,200 participants.

Lisa Brown, outreach coordinator for the association, said data from the rain barrel project will be ready to analyze next summer. Monitors in a common trunkline have been reading how effectively East Enders' barrels are keeping water from storm sewers.

"We want to see at least 10 percent reduction," she said.

The care and feeding of a rain barrel is easy, but it was daunting at first. The messy part is cleaning the filter sock and cylinder it's attached to. Every so many weeks, I pull the cylinder out and empty it of water and clean the filter of sediment and leaves. If you do it less often, it can get pretty gunky and stinky.

To install the rain barrel, you have to cut your downspout so the upper part meets the barrel's intake port. Because my barrel is on the back patio, I removed the bottom piece completely so the storm drain can no longer receive water. If you keep your barrel on or near a public sidewalk, that's not advisable because overflow could cause ice to form.

My barrel is a dark green 132-gallon UV-stabilized low-density polyethylene monster that has worked well on my back patio until recently. Last month, I noticed water pouring from the cylinder straight down onto the patio, even though the setting was on "collect."

It turns out that the RiverSafe barrels, which you cannot see into or clean inside, may collect sediment -- fine particles that the supposedly state-of-the-art sock at the end should keep out. In the spring, I will figure out why my cylinder is leaking. If I can't fix it, I plan to get one of the Quick Clamp barrels that the watershed association has since switched to.

A company near Zelienople called Quick Clamp makes them from a design on which the watershed association has a patent. The top comes off so it can be hosed out, and the Allegheny County Health Department has approved it.

Ms. Brown said the RiverSafe barrels were difficult to clean, "and we also had problems with the spigot at the bottom being too far down. We have a siphon overflow system on ours."

If you want one, you pay their cost, $275 plus 7 percent tax, and they will deliver and install it for $125.

For questions or to inquire about a rain barrel, call 412-371-8779 or e-mail rainbarrels@ninemilerun.org.

Doug Oster writes a blog, "Growing With Doug," exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.