Rainwater harvesting systems in cold climates

Phillip this is a really good website with lots of good resources.
http://www.harvesth2o.com/

I also have a book called ‘Design For Water’ by Heather Kinkade-Levario. It’s full of technical information, photos and diagrams of actual systems. A cistern in a cold climate like where I live (Maryland) should be thought about like a septic tank. Frost line here is 24″-30″ and there are plenty of tanks where the lid is not even that deep and we never have a freezing issue. So check out these resources and post your pictures when you get a system built someplace.

-Miles

For any residential project, for constructing and maintaining, keep it simple. I’ve personally had to clean out large tanks before and its much easier if you’re able to get a ladder in the opening and crawl through. I would also think a direct line from your downspouts directly to the tanks, coupled with a first flush bypass type valve, would be the way to go. After the first flush drains away the water should be plenty clean for irrigation. Your flush and tank overflow could drain into a bioswale to keep more water on site if you’re trying to keep the water onsite. As far as your tank specs go, the manufactor should be able to supply you with that info.
Sounds like you’ve got an interesting project. I also recommend ‘design for water’ as Miles mentioned. Good luck. – Mike

Phillip I’m going to play devil’s advocate here. Are you going to be setting up a pump inside the cistern and using the water for a real irrigation system? Or will you just have the hand pump for hand watering? Unless you are either drinking the water or using it for an automatic irrigation system the whole rainwater harvesting into a cistern might be overkill. If it’s all coming off the roof I don’t think I would then send it back through the ground for filtration. I think you will loose a lot of the water when you send it though the birretention area (the idea is to harvest the rainwater, right?) and the water coming off the roof after the first flush should be pretty clean. I’m no expert, just surmising here. If you send the water through bioretention you definitely do not need a first flush device. If going directly to the cistern yes you do need first flush. If the tank is rated for burial you should not have a concern about structural issues but you need to check with manufacturer. Yes you will probably need to have the option of putting a person into the tank for potential maintenance. Depending on how the tank is rated for loads you should be able to put anything you want over the tank. And unless Chicago has a combined Stormwater/sewer system you might have issues connecting you stormwater management stuff to the sewer. I would encourage you to get that book I mentioned. Go United!

Re: Bob’s comments. Down in the virgin island where ALL domestic water is what falls from the sky they catch it on the roof, run it inot a tank and drink it. Period. Sometime there is a simple cartridge filter in the mix. I know they don’t have the air pollution issues we do, but It makes you think about how simple this really all could/should be.

try googling grey water systems for homes

to answer your question. you filter the runoff includng bath water, etc. into the tank which overflows via a cistern to the sewer and in some circumstances you may also need to flush filters. You then irrigate via the tank to the garden and it is possible to do that via a yacht style wind motor and.or solar power. A panel can also be used to warm the water in some applications but it is a case of putting together the system through the good offices of the main supplier. It is appropriate to allow use of the tank as a fire reservoir and return filtered water to the home to flush toilets and more. Sorry for where I am wrong according to parties you contact but this will give you a clue as to how much hose and kit you need for a full system and what different folk are likely to tell you. Hard tanks may have a hatch so you can get inside to fix or clean them some years.

Please consider local seismic and water table levels when planning burying tanks and how deep you do it.

Luv n Lite

Les Ballard

The project that I was involved with used a typical gravity roof drainage system with pvc piping going into a brand new 10,000 gallon (yea, it was a big one) septic tank.There was no need to filter the water through a bioswale because that was going to happen when it was sprayed as irrigation. The septic tank was to have a centrifugal pump in it. It was buried deep enough not to freeze and had an outfall pipe just like any septic tank for if and when the tank became full. That water went to a bioswale to infiltrate into the ground for replenishment and purification.. I did design a cleanout at each downspout that used 8″ pvc vertically so that there was a place for debris such as twigs or small branches to fall out and a sump for any sediment that could be opened and cleaned out.

I do not know if the system has been utilized yet.I switched jobs before it was complete. The piping and tank were in, but the pump system had not been set up. It was a historic restoration of a nineteenth century estate being funded by donations. They spent 6 million on the building, so the budget was slowing down the completion of the landscape. I really need to follow up on this.

Simplicity is the answer as someone else pointed out earlier.

here is a link to a photo of it going in: http://picasaweb.google.com/highfieldhall/HighfieldHallRestoration#5224349391871201266

It was fun and quite an experience dealing with many, many, groups with individual agendas. My portion of the job was not the overall landscape. I recommended that they find a Period LA which they did. I was responsible for parking and pedestrian circulation.

Interestingly, there were two brick cisterns found underground for water storage, quite possibly done when the house was built. These were almost certainly to store roof runoff. I’m not sure if the water was used to irrigate the cut flower garden and greenhouse that was over the edge of a cut bank quite near the house or for what I believe is the ruins of a fountain in a sunken garden on the other side of the house. The plan was to use at least one of those as well as the 10k tank. We also had plans for a second 10k tank under the parking (that did not happen as the budget was depleted and the parking was essential to generate income).

The parking was the most challeging political issue with the entire project. Aside from the various factions within the restoration group, there was the tree warden, the historic commission, selectmen, and others that had to approve it. There were 9 completely different parking concepts developed. I actually represented them at two major hearings after leaving the company because I had so much time and effort invested in it that I had to see it through.

The most satisfying part for me was that I was able to find a better solution for ADA access on the front entry than to have a similar ramp to that on the rear of the building that the architect’ had designed for the front. I had them make a masonry foundation to the porch and made the grading of the walkway stay below 5% and still have 2% positive surface drainage all along the house – one of those un-noticed things that have a huge impact on the outcome of a project..