# Capturing rainwater **URL:** \ **Category:** Factual Questions\ **Created:** [August 29, 2006, 9:33pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715 "2006-08-29T21:33:17Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![ComeToTheDarkSideWeHaveCookies](https://avatars.discourse-cdn.com/v4/letter/c/e9bcb4/32.png) [@ComeToTheDarkSideWeHaveCookies](https://boards.straightdope.com/u/ComeToTheDarkSideWeHaveCookies)\ **Post date:** [August 29, 2006, 9:33pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/1 "2006-08-29T21:33:17Z")
My Mom’s annual rainfall can average 200 inches. She lives in the coastal mountains of southern [Humboldt County](http://ca.water.usgs.gov/archive/waterdata/cnty/humboldt.html) , California, in the Mattole River watershed. My family has always relied on two springs on our property to supply the water for the two houses on our property. The holding tanks often get extremely low during the dry summers, requiring even greater conservation measures than are already taken year-round, such as taking “Navy showers” and my Mom pretty much no longer has a garden to speak of. We also now have a firehouse on our property, for the local volunteer fire company. It houses one small fire truck and one small tanker truck. While visiting home this summer, Mrs. Dewgrrl and myself wondered why rainwater capture was not more common in the area. I endeavored to do some research in support of a proposal to install cisterns on the highest point our property, near or on the same clearing where the firehouse stands. At that location, the collected rainwater could be used as both a gravity-fed source of water for various residential needs (toilets, showers, laundry, gardening) and as an emergency/backup water supply for firefighting needs. Using open cisterns seems the simplest way to solve the collection problem, but mosquitos are very much a factor in the region, not to mention all of the other resident critters likely to fall/climb in. Using open cisterns also minimizes the need for expensive excavation, but the location is prone to high winds and falling branches from the surrounding Douglas Fir, Tan Oak, Madrone, and other mixed chaparral. It just seems like an awful lot of rainfall not to try and take advantage of, at least to some degree, even with the potential open cistern issues. Any comments or suggested reading from insightful Dopers will be greatly appreciated. ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [August 29, 2006, 9:41pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/2 "2006-08-29T21:41:18Z")
I spent a couple of months at a place in Belize that captured rain water for drinking. There was a fine mesh screen over the very top - it was an enormous metal barrell, actually closer to bottle shaped. The mesh generally kept larger bugs and who knows what out of the water. I was told, and I never saw this myself, that over time a layer of moss will develop over the water and provide an extra barrier of protection. Again, I don’t know if that is accurate, but in all the time I drank that water I never noticed any bad taste and never got sick from it. ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [August 29, 2006, 9:47pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/3 "2006-08-29T21:47:32Z")
I spent a couple of months at a place in Belize that captured rain water for drinking. There was a fine mesh screen over the very top - it was an enormous metal barrell, actually closer to bottle shaped. The mesh generally kept larger bugs and who knows what out of the water. I was told, and I never saw this myself, that over time a layer of moss will develop over the water and provide an extra barrier of protection. Again, I don’t know if that is accurate, but in all the time I drank that water I never noticed any bad taste and never got sick from it. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [August 29, 2006, 10:00pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/4 "2006-08-29T22:00:43Z")
There are cisterns on Ocracoke Island, in the Outer Banks off North Carolina, where the groundwater is salty. The cisterns are usually concrete structures with tops, that look more like aboveground burial crypts than anything else to me. It looks like the only route in is down through the downspout and into the masonry - a pretty long dark narrow path for mosquitos to fly along, I’d think. But I’ve only seen them and don’t know much about how they work. ---
**Author:** ![Bobotheoptimist](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@Bobotheoptimist](https://boards.straightdope.com/u/Bobotheoptimist)\ **Post date:** [August 29, 2006, 10:01pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/5 "2006-08-29T22:01:44Z")
YMMV, but out here in droughtville I’m told that collecting rainwater can get you in trouble with the authorities - water rights are a tricky thing. IANAL ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [August 29, 2006, 10:37pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/6 "2006-08-29T22:37:56Z")
[QUOTE=Bobotheoptimist] YMMV, but out here in droughtville I’m told that collecting rainwater can get you in trouble with the authorities - water rights are a tricky thing. IANAL [/QUOTE] I can see it being a problem if you take it from a river or a well, but falling out of the sky? I have trouble seeing that, plus I imagine that she’d only be collecting a fraction of the total that falls on their property. Of course, I too ANAL. ---
**Author:** ![hawksgirl](https://avatars.discourse-cdn.com/v4/letter/h/ed655f/32.png) [@hawksgirl](https://boards.straightdope.com/u/hawksgirl)\ **Post date:** [August 29, 2006, 10:39pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/7 "2006-08-29T22:39:37Z")
[QUOTE=adam yax] Of course, I too ANAL. [/QUOTE] heehee. :eek: ---
**Author:** ![Ike\_Witt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ike_witt/32/283_2.png) [@Ike\_Witt](https://boards.straightdope.com/u/Ike_Witt)\ **Post date:** [August 29, 2006, 10:45pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/8 "2006-08-29T22:45:08Z")
[QUOTE=hawksgirl] heehee. :eek: [/QUOTE] It’s funny because it works on so many levels 😉 ---
**Author:** ![Bobotheoptimist](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@Bobotheoptimist](https://boards.straightdope.com/u/Bobotheoptimist)\ **Post date:** [August 29, 2006, 11:00pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/9 "2006-08-29T23:00:19Z")
[QUOTE=adam yax] I can see it being a problem if you take it from a river or a well, but falling out of the sky? I have trouble seeing that, plus I imagine that she’d only be collecting a fraction of the total that falls on their property. Of course, I too ANAL. [/QUOTE] Remember, people used to shoot each other about water rights in Colorado. I have no idea what it’s like out in California butt…er, _but_ rivers and streams rely on rainfall so capturing potential runoff is interfering with stream capacity. I’ve also been told that tossing dishwater on the lawn rather than letting it go down the drain annoys Denver Water Board as they have to release specific amounts for downstream use. Trivial tho it may be, what if EVERYONE conserved water? HUH? Ever think of that Mr. Smartypants? (Basic summation of DWB conservation policies) ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [August 29, 2006, 11:00pm UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/10 "2006-08-29T23:00:22Z")
[QUOTE=honeydewgrrl] Using open cisterns seems the simplest way to solve the collection problem, but mosquitos are very much a factor in the region, not to mention all of the other resident critters likely to fall/climb in. [/QUOTE] How about something like covering a couple hundred square feet of cleared hillside with heavy plastic sheeting. Prop it up around the edges and make a little spout at the lowest point that dumps into a better covered enclosed tank. A few hours of sunshine and the device should be dry to avoid mosquito issues. You might also be able to do it with sheet metal on sheets of plywood or something to make it more durable and less prone to physical and UV damage. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [August 30, 2006, 10:03am UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/11 "2006-08-30T10:03:31Z")
The city of Venice (the one in Italy) relied on rainwater during much of its history. Large paved squares sloped towards a drain, where water was filtered through sand on the way to the central cistern. You can still see the remnants of it. You could do the same, but you’d have to pump it out of the cistern, as the collection system runs on gravity and everything ends up at the bottom of a hole. ---
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [August 30, 2006, 10:07am UTC](https://boards.straightdope.com/t/capturing-rainwater/370715/12 "2006-08-30T10:07:34Z")
Or, you could just run a hose from [**Oregon sunshine’s place.**](http://boards.straightdope.com/sdmb/showthread.php?t=386062) He seems to have plenty of water to throw around.