Get our free book (in Spanish or English) on rainwater now - To Catch the Rain.

Difference between revisions of "CCAT greenshed rainwater catchment/2011"

From Appropedia
Jump to: navigation, search
(Testing Results)
(Next Steps)
Line 160: Line 160:
==Next Steps==
==Next Steps==
More testing would be really helpful and then fix whatever needed to be fixed.
Make sink gravity fed. Would suggest building greenshed wall higher to allow water storage to be higher, putting in a viewing window to see storage. With sink being gravity fed, decouple pump output and attach hose for a hose for that side of the property. The pump can also be used in the future to pump the water to a higher point on the property.
Improve on sink basin if desired.
Examine long term viability of unique storage container.
Improve filter system.

Revision as of 23:32, 6 May 2011

Engr305 Appropriate Technology page in progress
This page is a project in progress by students in Engr305 Appropriate Technology. Please do not make edits unless you are a member of the team working on this page, but feel free to make comments on the discussion page. Check back for the finished version on May 15, 2011.


In a space of less than 5 feet from gutter to the waters primary use, we have implemented a system that will filter the water, including a first flush filter, and collect it in an unique storage container. With the remaining 1-2 feet and insufficient water pressure to use the faucet, we have implemented a temporary pump priming system and pump faucet that can be converted to a pump hose and gravity fed sink in the future when a method to increase the amount of water pressure has been found and implemented. The sink drains have been diverted to a greywater marsh system whose outlet may be connected to the property drainage in the future.


CCAT volunteers are always busy and in need of a washstation for their new greenshed. There is an existing rainwater system with storage which is in good condition and used for summer watering, although this storage tank at the present time is reported to be exhausted before the end of summer. A second water supply and storage system will need to be designed for the greenshed. The water at present time drains behind the greenshed and runs into property drainage.

This could best be served using rainwater and the greenshed roof, which is a viable source for a rainwater catchment system.

Calculator V = R * A * k * e

V = (3.5 ft/yr)(96 sq ft)(.9)(7.48 gal/cu ft) = 2262 gallons / year

2250 gallons per year.


The objective is to redirect the 2250 gallons of water currently draining off the CCAT’s green shed and soaking the soil behind the greenshed wall and onto the property every year to a catchment system and an easy to use tool wash station. After the water is collected and used it should then be used for a secondary purpose in a greywater marsh. The water and the system should fulfill as many needs as possible.

Cost Estimate (not final)

Item Description Price Quantity Total
Filter Prevent large particulate matter $20 1 $20
Tank Water Bladder: holds 1057.53 gallons $200 1 $200
Sink Two basin kitchen sink donated 1 $0
Piping PVC some donated by CCAT some being purchased 4.86 10 $48.60
Marsh Method to use overflow and waste water donated 1-2 $0
Total Cost $268.60


The basic Criteria of planning our rainwater catchment system is function first, but based around user friendliness, longevity, and usefullness. The system has to be easy to use and rugged due the nature of the environment and able to withstand the test of time with minimal maintenance. Other considerations such as, how easy the system can be modified and aesthetics, are being taken into account as well. The following criteria will be used and with the highest score being considered over the others for the project.

Criteria Weight (scale:1-10) Constraints
Storage Uniqueness 10 location
Materials used 6 Minimize new materials and high imbedded energy
Usable sink 7
Ease of future modifications 9 Available location and budget
Ease of use 8 Is it versatile and simple
Self Sustaining 7 Is it self cleaning
Aesthetics 4 Is it camoflauged with the surroundings
Lifespan 8 Quality of materials and resistance to photodegradation

Rough Timeline

Week 0 = Finals week May 20th

Objectives Relative Week
Build framing Week 7 Mar 1st
Attach and test filter Week 6 Mar 7th
Start collecting testing storage Week 6 Mar 14th
Find overflow elevation/capacity Week 5 Mar 21st
Place and start siphon Week 5 Mar 28th
Connect overflow system Week 5 Apr 4th
Connect sink & Test sink Week 4 Apr 11th
Connect marsh to sink outlet Week 4 Apr 18nd
System complete Week 3 Apr 25th
Working system debugged or noted Week 2 May 6th
Working whitepapers - specs/docs Week 1 May 2nd
Appropedia/report COMPLETE Week 0 May 9th


Going through the building phase step by step! Starting with getting the water bladder, digging, and finally putting everything together.


Some notes:

  • The system will consist of a:

first flush filter storage transport to wash sink drainage transport to marsh

The design of the rainwater catchment system first starts with rain and the capture of it! The rain will fall onto the greenshed roof, which occupies an area of 96 sq. ft., and flow into the gutter. With limited space we decided to use a downspout in the gutter and channel the water to the greenshed wall where the filter is mounted. The filter will consist of a screen for macro debris and have the ability to create a small first flush system before it is directed to the storage bag using flexible ribbed hosing. Without enough drop for a self cleaning screen and too little room to have the filter be in a preferential area further from the storage we decided to attach the filter to the greenshed wall using masonry screws.

Due to everyones overall preference for a unique storage container, we decided to use a water bladder which has the limitation of top entry and exit from the container. While this ensures the maximum water pressure because conventional storage devices often put their outlets at the bottom, we still did not have enough pressure for a gravity fed sink, which is far easier to use than any other type.

After elevating our storage to the highest point possible that still allows room for a small filter, and lowering our sink or point of use below the standard still making it accessible, and changing our faucet and sink to optimize water pressure, we were still unable to produce enough water pressure to provide the sink with sufficient flow with only gravity.

To resolve the problem with insufficient flow, we revisted a design that incorporated a pump. While this is not optimal because it requires two people to operate the sink, we used threads and hose fittings to allow for removal or alternate use for the pump, should the problems surrounding a gravity fed sink be resolved.

The idea of a pump was also a help, because as previously mentioned the water needed to be siphoned out of storage and should the seal ever be lost a primer would be essential. The pump can provide an alternate function as a system primer. To use the pump as a primer and for water pressure on the sink we used two globe valves to control the direction of flow and by using threaded pvc at certain points it allowed the system to be easily altered in future alloing the pump to be used to work a garden hose.

We wanted to limit the amount of pvc and imbedded energy used so besides the sink drainage and pump mechanism we decided to use garden hose as it can be easily attached to pvc fittings and can be customized more easily with regards to the flexible storage container.

After using the pump or gravity fed sink we connected the typical sink drainage to a CVPC piping system that flows underground to a greywater marsh that has been sunken in the ground currently increasing water content in the soil surround the garden.

Testing Results

Filter Storage is vulnerable to puncture but easy to repair. Not enough water pressure for a gravity fed sink. Pump as siphon works. Pumping water to sink works but provides too much pressure and much be turned slowly. Pump is not ideal but works. Drainage is at proper declination for water to drain to marsh without appearant leakage or standing water. Marsh drains well and is at proper height.

Next Steps

Make sink gravity fed. Would suggest building greenshed wall higher to allow water storage to be higher, putting in a viewing window to see storage. With sink being gravity fed, decouple pump output and attach hose for a hose for that side of the property. The pump can also be used in the future to pump the water to a higher point on the property.

Improve on sink basin if desired.

Examine long term viability of unique storage container.

Improve filter system.


Lessons Learned

1. Have client define criteria or project prior to accepting.

2. If scope of project changes timeline should reflect changes.

3. Minimize points of contact from the client to prevent communication issues.

4. Get initials or sign off on all parts of project.

5. Require 24/7 or access to materials and tools.

6. If there is a conflict in direction, do not be in the middle. Open up communication and try to keep communcation written to force people to be on their best behavior.

7. Request clear grading criteria for project.

8. If I have to provide free labor for a class project, pick an easy project or a non-promotional project (one that is not a display).

9. This project would be a better project for fall semester since it doesn't rain as much until the end and allows the system to be used and tested during the spring, but starting the project in spring when it rains in the beginning of the semester and haults work also making difficult testing and use for the summer until the rains come again in excess.

Literature review


1. This book shows the right and wrong ways to build a catchment system. Also shows the steps on how to build ferrocement water tank and maintenance on tanks. It also talks about the history of rainwater catchment.

Gould,John. Rainwater Catchment Systems For Domestic Supply Design, Construction and Implementation. Southampton Row,London: Intermediate Technology Publications, 1999.

2. Shows how to calculate the efficiency of water from the storage tanks to farms.

Bos,M.G.. On Irrigation Efficiencies. 19 ed. Wageningen,Netherlands: International Institute for Land Reclamaion and Improvement, 1974.

3. Case studies from around the world using different types of catchments and also measure sediment build up.

Schick,Asher. Channel Processes: Water, Sediment, Catchment Controls. Catena Supplement 5. West Germany: Catena Verlag, 1984.

4. Ball Redbook 17th edition Vol. 1 Multiple descriptions and ideas of utilizing space for irrigation systems. Beytes, Chris, and Debbie Hamrick. Ball redbook . 17th ed. Batavia, Ill.: Ball Pub., 2003.

5. Greenhouse Operation & Management 6th edition More examples and ideas for transporting small scale amounts of water. Nelson, Paul V.. Greenhouse operation & management . 6th ed. Upper Saddle River, N.J.: Prentice Hall, 1998.

6. The Atmosphere an introduction to Meteorology Detailed information on interpreting weather patterns and atmospheric conditions. Lutgens, Fredrick K., and Edward J. Tarbuck. The Atmosphere an introduction to Meteorology. 10 ed. Upper Saddle River, NJ: Pearson Prentice Hall, 2007.

Peer Reviewed

1. Talks about different types of grey water (light grey water) . The benefits, nutrients that are good for irrigation. Or some effects on plants and what you should do to decrease risks.

"BC Green Building Code Greywater Recycling". (2007), (accessed February 10, 2011).

2. “Harvest the Rain” Article on rainwater catchment systems with multiple diagrams of filtration systems

Mother Earth News; Aug/Sep2003, Issue 199, p42, 7p, 2 Color Photographs, 3 Black and White Photographs, 3 Diagrams

3. Specifics towards maximizing the efficiency of a rain gutter drainage system. Arthur, S. "Recent and future advances in roof drainage design and performance." Building services engineering research & technology 26.4 (2005): 337-348.

Internet sites

1. Talks about where to put a marsh, how to build one and how it helps animals have habitats.

The Old House Web. "Backyard Wetlands: Mini-marshes Can Provide Benefits Of Natural Wetlands." (accessed 2/11/11).

2. Shows the process of how to install a sink outdoors

Ames, Daniel. "How to Add an Outdoor Sink." may 6, 2010. (accessed 2/8/11).

3. An idea for Rubbermaid trash cans for a water storage. Seeing if people used them and if they liked them.

"Simply Discuss: Rubbermaid trash can for water storage?." 03/07/2007. (accessed 2/8/11).

4. Flexi tube connection and inlet connection.

5. Solar Powered system, an idea should we find ourselves with excess time.

6. Modular Filtration and Storage system