Project data
Authors Joe Arcata, California Deployed 2009 USD 281.79 Rainwater catchment Download Upload your project too!body.poncho-dark-mode .mw-parser-output .mw-ui-button{background:#303134;border-color:#3c4043;color:#bdc1c6}@media screen and (max-width:500px){.mw-parser-output .button .mw-ui-button{display:block;margin:.5em 0}}
The old Rainwater Catchment system that was at CCAT.

Cal Poly Humboldt's Campus Center for Appropriate Technology (CCAT) was started in 1978 and has been going strong since. With three live in students per year, and 18 student employees, CCAT is a "live in demonstration home" where the students of Cal Poly Humboldt and the local community actively partake in creating and maintaining a home in a sustainable way, by incorporating many aspects of Appropriate Technology.

CCAT is in need of a reinstallation of their rainwater catchment system. A system had been installed at the original Buck house, but due to construction and relocation, it was dismantled. With many supplies ready for reuse, and the advantage of hindsight, it is now time to reinstall an efficient and aesthetically pleasing rainwater catchment system. Also, the CCAT house has just recently (January 2009) finished installing a new metal roof that will work wonderfully for a rainwater catchment system.

## What an Opportunity!

With CCAT striving to be a live-in demonstration of a sustainable home, and being located in coastal Humboldt County, California, it is just waiting for the water flowing out of the downspout to be redirected into a storage tank for later use for watering in the garden, the greenhouse that is being built, and any other needs except for drinking.

Two students from Spring 2008 ENGR 305 began working on the rainwater catchment system, but it was not completed. One student, Lauren, in Spring 2009 ENGR 305 class continued the work on this project. Once the plan was laid out, the complete construction of the system took place. The opportunity to learn about the application and installation of this type of system will be further spread to those who visit CCAT. There, people will be able to learn directly about how the system works through interpretive signs and other literature. As such, this project will benefit not only those who live in CCAT, but anyone who visits the demonstration home, as well as through this site for more information.

This project was then updated again in 2014!

## Criteria

Aesthetic
Because CCAT is a demonstration home, the system should look well built and maintained for the public. It must also be have a non-intrusive design, and be out of the way.
Budget
Initial cost should be reasonable for this type of system, especially since the main tank is already purchased. Hopefully, many materials will be found that are not in use, but can be reused, so as to help keep the expense as low as possible.
Durability
The system needs to be able to withstand the weight of the water in the storage tank when it is full, and the tank should be secured so it won't blow away when it is empty. Care must be taken to ensure the tank will be stable when it is full and empty. It must be made well so that there will be little maintenance required later on, and it will be able to last a good amount of time for the CCAT house.
Educational Value
The system must have some educational value for the public. Again because of the CCAT house being an educational demonstration home, the system will have an education poster that explains the system as a whole, and how other community members may pursue their own construction if desired.
Efficiency
The retained water needs to be easily accessible for daily agricultural use. The tank needs to be sited in such a way that creates the maximum amount of head to decrease the amount of pumping necessary to move the water uphill.
Functional Design
It has to work. The tank must not leak, everything must work and be able to be maintained easily. The tank must be accessible and out of the way. The filter system must work, and the overflow should be directed to a useful area, while the water stored is able to be accessed easily as well.
Purity of Water
The first flush system must also work well by rejecting the first amount of rainwater, keeping it free of dust, debris, bugs, and dirt, so that the water is as pure as possible.
CCAT approval
The rainwater catchment system is designed especially for CCAT's water needs. It is important to make it to help the house and surrounding area, while being able to expand on the system and make changes as needed later on, as they arise.

## Design

### Tank

CCAT has a tank already which will be used for this project. It is 7 feet tall, and 5 feet in diameter. This results in about 1500 gallons, which weighs about 12000lbs. when filled. We will need to excavate an area were the tank is to be placed. Originally, we thought of putting a 6ft x 6ft x 8in concrete pad down to support the tank. However, it was decided that for tis project we would not use concrete. Instead, I dug down about 8" in the area where the tank would be placed. Then I compacted the Earth down, put a layer of bricks (approximately 4" thick)on top, and then about 2" of gravel on the top of the bricks to support the tank.

There was a good deal of debate and concern over where the best place for the tanks location would be. It was finally decided that the best location would be outside the main entrance of the CCAT home, near the bike rack, and directly next to the tires. Though this spot is obvious to the public, it is not in the way of any foreseeable future projects, and will attract attention to the project and heighten peoples awareness of rainwater harvesting. The tank is up high, and it will be easy to attach a hose to it, so that access to the water for gardening purposes is very accessible. Th tank does not get any shading in its location, which is often considered a more ideal situation to help prevent heating, and additional leaching of chemicals through the plastic.

### First Flush Catchment System

After a few different attempts to create a first flush, I found a system that has seemed to work well so far.

The collected rainwater will be gathered in the roof gutter and then pass through a small leaf catcher that is meant to separate the larger debris from going into the piping. Then the PVC piping will carry the water down towards the tank. Then it will reach the first flush device, where the water will fill a small 15 gallon tank that I purchased at Resale Lumber Products. The water will flow into the small tank until it fills. Then there is a small racquetball that is held up by a small piece of wire to keep it from falling into the tank. When it becomes full, the ball will move up through the clear piping piece. Then there is a ABS piece that converts the piping from 3" to 2" where the ball will fill up this smaller space. The water will then continue to flow and be diverted into the large 1500 gallon tank.

This will allow any smaller leaves, bird droppings, and general sediment that may have built up on the roof to be initially diverted into this flush system, so that the clean rainwater can be stored in the large tank.

To size the amount of water that should be used for a first flush: It is estimated that for every 1000 square feet of collection surface, the first flush should divert a minimum of 10 gallons.(Kinkade- Levario) This is a standard rule of thumb that usually works. For this roof the surface area was approximately 49' X 32', equaling 1568 ft2, so a 15 gallon tank seemed most appropriate.

### Delivery System

The Delivery system is simple, a length of 3" PVC pipe directed from the Roof Washer to the First Water Catchment System. I used some ABS piping pieces for connectors also(these are the black ones pictured). I put up a 4" X 4" cedar post into the ground next to the cement curb driveway to keep extra support for the piping.

### Roof Washer

The roof washer is mounted to small pieces of wood attached to the side of the housing. I used a small recycled detergent bucket and cut it at an angle, then placed a screen on top of it. To secure the screen I put four small hitch pins into the sides so that it would be possible to remove. This is meant to keep the larger debris out of the system. Then I put in the 3" PVC coming out of it which would bring the water down towards the first flush.

## Budget

Budget: This is the budget for what was spent on this project.

Qty Material Needed Source Cost Total cost
1 1500 gallon Tank CCAT Already available $0$0
1 20 ft. 3" PVC Piersons Hardware Donated $0$0
1/3 yard #2 Rock Wes Green Landscape Materials $40.00/yard$13.33
1 15 gallon bucket Resale Lumber $25.00$25.00
2 ft. 1/8" Screen filter Hensel's ACE Hardware $2.00/ft.$6.62
1 Hose bib attachment for 15 gallon tank Resale Lumber Products $18.90$18.90
1/2 ft. Tube Spa Piping Hensel's ACE Hardware $4.49/ft.$2.25
1 Silicone Caulk Hensel's ACE Hardware $4.99$4.99
1 Plastic Funnel Hensel's ACE Hardware $7.49$7.49
1 3" Bulk head fitting ACE Hardware- Thrifty $30.50$30.50
2 5x7 tin shingle Piersons $.39$.78
1 ABS 90 degree elbow Piersons $5.75$5.75
1 masonry bit Piersons $4.99$4.99
2 Shelf and Rod bracket Piersons $2.99$5.98
1 circle cutter Piersons $10.99$10.99
1 copper coi Piersons $2.89$2.89
1 no-kink faucet 3/4in Male IPS Piersons $5.95$5.95
1 PVC bushing Piersons $1.49$1.49
1 fasteners bolts screws and nuts Piersons $1.69$1.69
1 ABS 3" adapter Piersons $4.19$4.19
1 Strong-tie post cap/base Piersons $3.34$3.34
1 Bushing PVC 1.25M/4FPT Piersons $2.79$2.79
1 power pro 10x 3 1/2 Piersons $4.49$4.49
1 ABS knockout closet flange Piersons $2.75$2.75
1 Front Elbow Galvnz Piersons $1.99$1.99
1 PVC Cement Piersons $3.99$3.99
1 ABS 3" cleanout adapter Piersons $3.69$3.69
1 ABS 90 degree elbow Piersons $3.99$3.99
1 flexible coupling 3x3 Piersons $6.99$6.99
1 flexible coupling 3x 1 1/2 Piersons $7.49$7.49
1 teflon tape Piersons $.99$.99
2 fasteners bolts screw and nuts Piersons $1.69$3.38
10 screws Piersons $.12$1.20
10 screws Piersons $.19$1.90
1 4x4 cedar post Piersons $29.43$29.43
1 ABS coupling West Coast Plumbing $2.49$2.49
1 ABS sanitary tee West Coast Plumbing $7.89$7.89
3 ABS coupling 3x2 West Coast Plumbing $3.95$11.85
1 ABS pipe West Coast Plumbing $.79$.79
1 ABS pipe West Coast Plumbing $1.79$1.79
2/2 Hitch pins Hensels ACE $.19/.23$.84

## Operation and maintenance

Please see CCAT rainwater catchment system/OM for detailed operation and maintenance instructions.

## 2014 Conclusion

### 2014 Testing results

No leaks were detected in system when rain fell onto CCAT roof and traveled through system.

### 2014 Discussion

Testing results indicated that the slope of the screen was not accurate, adjustment was made and now accumulation of debris seems to be minimal. As rain accumulated in gutter there were no leaks and water was caught by bucket and transported by 3"PCV to storage tank to where it is held until used. Overflow works well, directs water away from tank and kept original 1" hole size.

### 2014 Lessons learned

Allow more time for mistakes to be made, such as varying types of PCV and PVC sized piping depending on if it is designed for plumbing. A project that seems small, may not be. Even if a project seems small, grab someone else to work with, it will help the process go smooth. Start as soon as the projects are given out instead of 3 weeks later.

### 2014 Next steps

This project should be self sustaining for years to come, however spots of the house wall still need to be paint matched, where old L braces were previously located. The gutter patch needs to be textured and paint matched to draw attention from the current color difference. Also to improve flow more head is needed, which is impossible given the current conditions. The attachment of a pump will improve flow rate by roughly 30%.

## Update September 2018

The CCAT rain catchment system on the main house is still fully functional. The roof and gutters need a cleaning and the rest of the system is intact. There are some small leaks on the piping leading to the Storage tank. The pipe leading to the first flush has been replaced with an opaque one to prevent algae growth.

## Update September 2019

The water is only supplying the plants in the off-raining seasons in Arcata - for the system to be more useful, the water collected should supply water for different uses. For example, the gutter system is only leading to a bucket and has no other use. A possible solution for this would be connecting the system to CCATs outdoor sink.

Another issue that the system is currently facing are leaks. There was one between the filtration system and the conveyance system, and at the connection of the conveyance and the first-flush system. The solution that needs to be implemented is new positioning with proper sealant to fix the leak and make it easier to clean and maintain. CCAT needs to act on this quickly before the rainy season.

The gutters have not been cleaned since 2018 due to the hazardous nature of students going on rooftops when it is raining to clean. A solution for this would be having a trained maintenance professional, CCAT co-director assigned days to do this, or a specialized tool that would allow students to clean the gutters from the ground.

Overall, the rainwater catchment system is currently active and functioning.

## References

1. Schiller, E.J. and B. G. Latham 1987. A Comparison of Commonly Used Hydrologic Design Methods for Rainwater Collectors, Water Resources Development, 3..
2. Another example of footnotes.
3. This is an example of a named reference. You can use these named references to repeat citation content throughout the document.
4. Dwayne Taylor, Jonathan. "Rainwater collection and distribution apparatus." United States Patents 1 (1998): 1-3. Print..
5. Scilink. "Rainwater Harvesting." Rainwater Harvesting. N.p., n.d. Web. 7 Feb. 2014. <http://www.kidsfromkanata.ca/files/rainbarrels.html>..
6. "Rainwater Harvesting." Wahaso Water Harvesting Solutions. N.p., n.d. Web. 6 Feb. 2014. <https://web.archive.org/web/20190916075929/http://wahaso.com/rainwater_system.php>..
Page data
Type Project ccat, rainwater, rainwater catchment, plastic funnel, pvc, screen filter, silicone caulk, tank SDG06 Clean water and sanitation, SDG11 Sustainable cities and communities Lonny Grafman, lauren proctor, coulter taylor, Annie Welbes, Christian Nielsen, Alyssa Della Ripa 2009 CC-BY-SA-3.0 Campus Center for Appropriate Technology (CCAT), Cal Poly Humboldt Students, Engr305 Appropriate Technology AcquaTank, ESEN Water Catchment System English (en) 3,316 Lonny Grafman, lauren proctor, coulter taylor, Annie Welbes, Christian Nielsen, Alyssa Della Ripa (2009). "CCAT rainwater catchment system". Appropedia. Retrieved August 16, 2022.
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