water catchment

[SouthKona]

we are getting ready to put in a water catchment system. any hints ("I wish i'd known that BEFORE i put in my system" sort of thing)? recommendations on size of tank, type of tank, filtration? thanks.

[jdub]

Re: water catchment

As far as the size of your tank and filtration options, I'd check with whatever municipl authority applies to your location (I'm not sure what that is in your area of SouthKona). Projected consumption, possible airborne pathogens, chlorine maintenance, pumping options and St DOH requirements are all pertinent to your choice. Retro-fitting is complicated and hopelessly costly, so ask a lot of questions of whatever authorities or contractors you speak with about yout catchment system.

[kimo55]

Re: water catchment

we are getting ready to put in a water catchment system. any hints ("I wish i'd known that BEFORE i put in my system" sort of thing)? recommendations on size of tank, type of tank, filtration? thanks.

maybe...

http://water.usgs.gov/wrri/97grants/gu97sei2.htm

http://www.ctahr.hawaii.edu/ctahr200...TMacomber.html

http://westhawaiitoday.com/articles/...features03.txt
bobco
vinnie
for access

[SouthKona]

Re: water catchment

thanks for the tips. and, join me in wishing for year round rain.

[craigwatanabe]

Re: water catchment

The most important aspect of any new catchment system is if it will be used for potable water catchment.

If yes, then make sure you don't use galvanized nails or screws. In any case make sure if using fasteners of different metals to use the neoprene or Neo nails to isolate one metal from the other.

In areas where there is a little rain certain times of the year, consider using a diverter. This device will allow the initial rain to wash the roof clean and send this initial flow of water down the downspout. Depending on the type of diverter, it will eventually stop allowing the runoff to be diverted to the catchent tank.

Don't consider using a catchment system if there are trees nearby where the leaves can contaminate the water supply or overhanging trees where rats can get onto your roof and urinate.

Don't go the cheap method. Some people like to use those free-standing vinyl swimming pools because it's large size, filtering system and relatively low-cost ($700 on up) seems like a nice bargain for what you get. Vinyl pools when left in the sun to heat up with water in it will leach out harmful and cancerous PVCs into the water system. You've tasted it before when you drink water from a water hose left in the sun, it has that chemical taste.

According to water haulers, some of the better catchment tanks include fiberglass and metal "doughboys" with metal tops and can last around 10-years.

For a family of four, consider a 10,000 gallon tank and with no rain, expect to fill it roughly every 6-weeks at $75 to $85 per 4,000 gallons delivered.

You can use a shallow-well pump to keep your plumbing pressurized at a nice 40-psi. I use a carbon filter just after the pump trapping down to 1-micron of particulates and odor (if any). At the kitchen you can use a reverse osmosis or UV filtering system if you want absolute biologically pure water. Otherwise standard carbon filtering like those used on refrigerators or faucet mounted units like PUR is sufficient for clean and potable water.

On the shower heads use flow restrictors to maintain positive water pressure throughout the system. And make sure on all of your water spigots/bibs to attach checkvalves to keep your catchment tanks free from backflow.

[cezanne]

Re: water catchment

On the Big Island, is a water catchment system an alternative or a supplement to tapping into a water main, or do you have no choice but to install one?

[kimo55]

Re: water catchment

On the Big Island, is a water catchment system an alternative or a supplement to tapping into a water main, or do you have no choice but to install one?

depends on the exact area.
some no choice but catchment.
other areas, a financial necessity as a supplement

[Miulang]

Re: water catchment

In the hinterlands where Craig lives (Keeau/Puna), I think you have to have a catchment system if you want water. No water lines and probably no sewers out in that part of the world yet, either, until there are more people and then there might be a requirement for water lines and sewer systems. At that point the real estate values will really skyrocket. When you get city amenities (like residential home delivery of the mail, water and sewer lines) is when your taxes start to go up. But if you got the pioneering spirit like Craig, it's a great opportunity to get a relatively good deal on a house, compared to Kona or on Oahu, Kauai or Maui.

Miulang

[cezanne]

Re: water catchment

Oh OK thanks...

[DaveNSoKona]

Re: water catchment

My 2 cents...

The people that built our house used asphalt shingles, which pretty much excludes catchment from the roof area from being used as drinking water. You really get used to it over time. If it doesn't rain there are several water haulers in Kau and South Kona. Make sure that your tank placement is accessible to a fairly large truck in case it stops raining for a while. There is a calculation for the size of the tank depending on your catchment area, rainfall etc. My advice is to get the largest one you can afford. We have an 18K tank for each house. The building inspector said you need engineering (permit) if its over 5' or 6' tall. Most of the tanks here are made of corrugated sheet metal with a plastic liner. We have replaced one liner in the five years we have lived here but the other liner has been fine for 10+ years. Consider a cover that is supported above the water if you don't want to watch birds bathing in your tank. This involves metal poles above your tank and is a bitch to install (3 people min.)

If you want you can come by and look at ours in South Kona.

[craigwatanabe]

Re: water catchment

In the hinterlands where Craig lives (Keeau/Puna), I think you have to have a catchment system if you want water. No water lines and probably no sewers out in that part of the world yet, either, until there are more people and then there might be a requirement for water lines and sewer systems. At that point the real estate values will really skyrocket. When you get city amenities (like residential home delivery of the mail, water and sewer lines) is when your taxes start to go up. But if you got the pioneering spirit like Craig, it's a great opportunity to get a relatively good deal on a house, compared to Kona or on Oahu, Kauai or Maui.

Miulang

The lack of county water hasn't detered housing prices in Keaau down by the ocean.

As a matter of fact, home prices are higher in my area that's closer to the ocean than other properties that are closer to the highway or in Hilo where county waterlines are commonplace.

To me having a catchment system is the better way to go. It makes you more aware of water conservation and the water (in my area) is sweeter than county water, it's also softer.

As for pioneering Miulang...my area is building up so fast that I've got neighbors up and down my road where just two years ago there was nothing but empty lots with lots of tall grass and wild bamboo orchids growing everywhere.

There's a new home coming up almost every month and the sound of bulldozers clearing lots and cement trucks everyday is making this area look like suburbia. It's amazing! It's not so rural anymore.

[SouthKona]

Re: water catchment

thanks for all the info. it sounds confusing, but then again, im used to just turning on the faucet and: whosh, water. re: tank placement, and the comment to make it accessible to the water truck, please tell me that they have a long hose they can use to get to the tank?! maybe i need a water truck to visit our site before we put in the tank. we've got plans for the house to be between the end of the driveway and the water tank......

by the way, least everyone think that the county supplies water to the developed areas of the island, did you know that waikoloa has to buy its water from a private company. waikoloa pays some of the highest taxes, yet does not have county water.

and no, i'm not putting in a catchment system in waikoloa.

[DaveNSoKona]

Re: water catchment

Here is my tank with cover and overflow valve:



The below pic tries to show that a 6000 gal water truck (full size over-the-road semi type truck) can navigate down a 450 foot grass driveway if it is straight and flat enough and pump water 20-(40?) feet from there.



FYI - I have seen water trucks hooked up to pipes on the highway with no tank in sight.

[SouthKona]

Re: water catchment

thanks, davensokona, for the pics. you brought up an interesting thought, maybe one just has to put in a pipe from the water tank to the location where the water truck will park. i suppose my husband already knows what he wants to do, humm, maybe i need to ask him what he has planned.
you must live on the "wet side" of so.kona, 'cuz your pics show a lot more green grass than anywhere around MY part of so.kona! i thought only waimea had a "wet side" and "dry side"....

[DaveNSoKona]

Re: water catchment

I don't know about wet/dry sides of Kona but I failed to mention that we haven't had to buy/haul water in a year and a half. We are mauka of highway of Milolii and most of the farms in South Kona in-between Kipahoehoe and Manuka Natural Reserves above 1500 feet elevation look like this. (not being on a recent lava flow helps too) We are also close to the recent Nature Conservancy acquisition in Honomalino of 4000 acres.

Being near so many big trees helps with getting more rain caused by mauka/trades afternoon showers. Big trees tend to attract more rain for some reason.