In 2008, Mike Schaefer and Lisa Maguire decided to do something about their pool.
“A couple of years before we did this I was out here sweeping, cleaning the pool, and I was thinking to myself: 'I’m going to wind up selling this house because of the pool. The maintenance on the pool is just going to drive me nuts',” Schaefer says. “That’s when we started brainstorming about turning it into a garden.”
So Schaefer and Maguire decided to retool their pool into a giant rainwater harvesting tank and food garden. They already had a 1,200-gallon cistern connected to their roof, but Schaefer calculated that he wanted 10,000 gallons total so that all of their plants, including food plants, would be watered with rainwater.
“We have all this effort put into this beautiful cistern, this big cement thing that holds water. Why not use it?” says Schaefer.
So they got to work. Schaefer designed the plumbing system and figured out how to get about 9,000 gallons of storage in the pool without any issues with smell or mosquitoes. He also wanted to use local and recycled materials as much as possible. In 2009 they did all the plumbing, wiring, prep and passive rainwater harvesting basins in the front yard to maximize their water collection on the landscape. In 2010 the pool project began.
Their design was inspired: They lined the pool with recycled billboard plastic, stacked empty 55-gallon plastic food barrels and culverts vertically inside the pool, then filled the remaining space with gravel. Schaefer calculated that the gravel portions were about 33% water by volume. Using the 70 food barrels and 13 culverts (which of course were 100% filled with water) gave them a total volume of about 9,000 gallons.
Schaefer and Maguire lined the pool with recycled billboard plastic, then filled much of the space with recycled food barrels and culverts to maximize water storage.
The food barrels were bought cheaply from local businesses that had plenty of empties, such as after transporting olive oil. Maguire would stop over on her way back from work and bring 6 barrels at a time in her truck. They would rinse out the olive oil (or other foodstuffs) and then stack the barrels inside the pool.
“After it was done, our neighbor came over and said ‘I really thought you guys were making crystal meth or something,’ because we were washing the barrels out in the back,” says Schaefer. “He thought we were doing something nefarious.”
The culverts were bought used off Craigslist and hauled with their trailer. Their planting pots, which grow a variety of foods and herbs, sit on top of the culverts. They had to do a bit of searching to find the right size pots, so that the lips would hang on the top of the culverts. “You want a thick one, because the lip of it is holding a lot of weight,” says Maguire. Ropes at the bottom of pots drop down through the holes in the pots' bottoms and reach down to the water and act as wicks.
The largest culvert is 36 inches wide and was placed in the deep end of the pool. Schaefer placed a submersible pump in it to move the water around the yard where needed. The pump is accessed by putting a ladder into the culvert. Plumbing between the pump in the pool and the front yard allows for watering of plants with just the turn of a valve. Pipes go to areas of the yard where they want to water, like the front yard or the water feature.
The gravel holds the barrels and culverts in place. It was delivered into the pool via a temporary chute, but a lot of it had to be wheelbarrowed by Schaefer and Maguire.
Schaefer and Maguire built a temporary chute to help fill the spaces between the barrels with gravel. The gravel holds the food barrels and culverts in place.
Schaefer has also installed a clever water gauge which floats up and down depending on the level of the water in the pool, so they always know how much they have. They empty the pool and water all of their yard trees before monsoons and before winter rains.
All the food plants and nearly all the other yard plants are watered with the collected rainwater, without need for municipal water. The rooftop harvests around 1,200 gallons and the pool about 9,000, giving them 10,000 gallons of rainwater twice a year (on average) to use in the garden.
The entire project cost them $4,000, and they got $1,000 back from the city of Tucson through its Rainwater Harvesting Rebate program.
Schaefer and Maguire grow herbs, tomatoes, chilies, and a variety of other veggies. Schaefer has noticed that some of his frost-tender plants like tomatoes and basil last several years thanks to the microclimate over his giant rainwater tank. “Our plants tend to do better in the summer because they’re cool … there’s cool water underneath everything. And then in the winter it’s warmer down here.”
This part of the former pool has a water feature and large pots for growing veggies and herbs. Everything is supplied with rainwater.
The plants in the front yard are mostly natives which do well without watering most of the time but their trees get extra water from the system a few times a year. In addition, the front yard has berms and basins to catch rain and allows for a lot of passive rainwater harvesting. This keeps flowing water in his sloped yard rather than having it flow past his yard and into the nearby creek. “That’s almost more impactful than our (active rainwater) harvesting,” says Schaefer.
Schafer and Maguire love their pool conversion. Not only do they conserve water, but the huge rainwater tank has been trouble-free. The only issue they had was a pump failure a couple of years ago while they were out of town which resulted in the loss of some food plants. There’s been no smell or algae, and no mosquitoes.
They have put together an online guide for anyone who’s interested in following in their footsteps.
The final pool area is tranquil and provides lots of space for growing food plants. The plant pots hang over the culverts and ropes through the holes in pot bottoms drape down and act as wicks.
For those who are tired of the maintenance and costs of their pool, this DIY conversion is just one of the options. Pools can be repurposed into storage areas, sunken gardens or patios, or filled in with dirt and abandoned — or removed altogether.
The city of Tucson has a useful website to help determine the costs of pool removal. There are about 16,000 pools within the city limits, says Candice Rupprecht, Tucson's water conservation program manager. In the city's greater service area there are about 20,000 more.
"The average to Tucson Water customer uses about 72,000 gallons per year," says Rupprecht. "And the studies that we've done have found that pools use almost 30,000 gallons a year. So pool owners are clearly not representing the average user. That's more than a third of the average annual residential usage. And so we were really ... looking for strategies and resources to give customers who just for whatever reason don't want a pool anymore."
The site has a handy cost calculator to help you determine how much you’re spending on your pool annually, and also includes cost estimates for various pool removal options. Pools can lose up to 2,000 gallons of water to evaporation per month in the summer in Tucson. They also require regular maintenance, chemicals, and a fair amount of electricity to operate the pool pumps. The city of Tucson estimates pool removal costs between $1,800 and $9,000, depending on what option you choose.
Schaefer, however, thinks that removing a pool is a waste of a great resource, and encourages homeowners to take advantage of the pool.
“It’s actually an asset even if it’s not a pool. If you don’t think of it that way you’ll just put a hole in the bottom and fill it with dirt. Make something useful out of it instead of just pretending it’s not there anymore.”
Sustainable gardens have a very positive impact on the environment and local wildlife.
