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CCAT greenhouse rainwater catchment

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Revision as of 17:10, 15 May 2019 by Kds20 (Talk | Contributions) (Abstract)

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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 23, 2019.


The Greenhaus Rainwater Catchment System is introduced to CCAT through ENGR 305: Appropriate Technology. The purpose of the system is to supply water over the summer to the Greenhouse plants through the Storage Tanks and the Hugelkulture bed through the Overflow. The building and supplying of the system are simple and easily, for the system consists of only 8 parts! The parts being: Catchment Surface, Gutter, Filtration, First Flush, Conveyance, Storage, End Use, and Overflow. This system is designed to ensure Appropriate Technology standards that are locally sourced, communally accessible, and environmentally less harmful than conventional, industrial water systems in the United States.


Outside CCAT sits a sloping glass greenhouse. Many changes have occurred in and around the structure during its time at the Campus Center for Appropriate Technology including separation from the main building, construction of a new wall using beach grass as insulation, and a floor reconstruction that's occurring concurrently with our project to build a rainwater catchment system for the greenhouse. CCAT wanted a rainwater catchment system to be built off the greenhouse to catch the rain that would just run down the building and into the ground beneath below. The water captured from the rain will ensure that the plant life at CCAT will be adequately watered when necessary.

The CCAT Greenhouse as of February 21st 2019

The CCAT Greenhouse when facing North West
The CCAT Greenhouse when facing East
The CCAT Greenhouse when facing West

Problem Statement & Criteria

The greenhouse at the Campus Center for Appropriate Technology doesn't have a renewable system to ensure the flourishing of the plants inside. The objective of this project is to build a rainwater catchment system for the greenhouse at CCAT to employ the use of our local weather patterns to water the plants within and outside of the greenhouse. With this renewable source CCAT can reduce their carbon footprint and create a sustainable resource to utilize.

Below is the criteria for the greenhouse rainwater catchment system. The criteria is scaled on a 0-10 high.

Criteria Constraints Weight
Functionality System is expected to run efficiently and effectively
Safety Must be in a secure location where it is easily accessible, also must be out of walkways, doorways, and head space
Aesthetics Must be pleasing to look at and enhance the CCAT environment
Budget Project will not exceed team budget
Durability Must be compatible with structure
Adaptable/Maintenance The structure should be able to be adjusted and mended
Accessibility Filtered rainwater should be easily accessible
Pairability Repair greenhouse cracks
Simplicity Weight should be minimal
Purpose Successfully captures and stores rainwater, educate, and be used for solar shower

Literary Review

This Literature Review will cover aspects of our greenhouse rainwater catchment at CCAT. Including, the climate for the area, filtration types to use, CCAT background, and overall design of rainwater catchments.

Rainwater Catchment Design

Rainwater design has been worked with for millennia. Ancient civilizations in modern day India and Israel are recorded using catchment methods as early as 3000 BC and later on the Romans developed vast systems of aqueducts, gardens, and pools all fed by rainwater. Since then rainwater catchment has gone into and out of style many times as other technologies developed, but it remains the most reliable and renewable way of attaining access to water. There is no one way to catch rainwater and design varies depending on many different variables including location, weather patterns, end usage, community utilization, etc.

The main parameters for these systems are rainfall, catchment area, collection efficiency, tank volume and water demand. Systems should be tailored specifically to the community they're serving, so a good place to start you design process is on the ground with the people who will be using it.

Catchment design can be broadly categorized into active and passive systems, where active is a system that is built and maintained through human activity and passive is a system mostly in place in the environment that is initially worked on and then maintained by humans. We'll focus on active systems as the project we are working on will fall into that category. In active systems there are some fundamental components.

Component Description
Catchment Surface Where the rain is falling
Conveyance Transports water from catchment surface to end use
Screens Filters out debris
First Flush Diverts initial most dirty water
Storage Holds water til later use
Overflow Allows excess water to go into Hugelkulture
End Use Water Plants in Greenhouse!

For each of these components there are different materials and technologies you can use.


This project takes place at CCAT located on the campus of Humboldt State University in Arcata, Californa. Arcata receives about 46 inches of annual average rainfall with a annual average temperature of about 53 degrees Fahrenheit. The city recieves its most rain during the months of November,December, January, and February. An average year in Arcata receives 175 days of sun and on average, 77 days of precipitation.

CCAT Greenhouse

The CCAT greenhouse is located outside of the CCAT building in Arcata, California at Humboldt State University. The greenhouse is constructed of a Beach Grass Clay Slip Wall and a Sturdi-Built prefabricated greenhouse structure. The frame is made of redwood, which is resistant to decay. Preventing decay in a greenhouse structure should be cheap, effective, and non-toxic to plants and animals. The highest recommended solution against wood rot is redwood stain. With the high amount of rainfall that is present in Humboldt County, it is important to ensure the structure is secure. During the Summer the greenhouse requires additional water. In addition to the greenhouse, water is needed to care for surrounding plants and crops. Agriculture is the largest consumer of freshwater. By cutting down the overall water needs for CCAT's agriculture and greenhouse, it can become a high opportunity for a positive environmental impact.

Water Filtration Systems

Filtration for our system involves a series of mesh filters that catch debris. The first of these is found at the end of the gutter system. It’s an angled black funnel with mesh siliconed to the rim; as rainwater falls from the gutter, it passes through the mesh while larger debris is reflected and bounce off. The second filtration system is the mesh lid leading to the first storage tank. This final filtration guarantees that no larger debris end up in the storage system.


In this section, we will be going over the construction of the the project. This will include some of the design stage, the prototypes that were created and though of, construction of the rainwater catchment system, and finally the final results.


Task Description Proposed Date Actual Date
Scope out project area Get a feel for the space, start to come up with prototype ideas February 26th, 2019 March 5th, 2019
Create prototypes Come up with different routes to take on this project, focus on placement of rainwater system components, design for desire and function March 12th, 2019 March 12th, 2019
Meet with CCAT Talk with them about their goals of the rainwater catchment and discover end goals of rainwater March 26th, 2019 March 27th, 2019
Weekly CCAT meetings Attend weekly CCAT meetings to discuss project progress, improvements, and feedback Weekly Weekly
Start to gather materials Look through supplies at CCAT and find things that we can use for the catchment system March 12th, 2019 March 27th, 2019
Meet with Risk Management Lonny ended up becoming the spokesperson when it came to facilities management and met with them on our behalf April 1st, 2019 Varies
Start construction Break ground on our project, brought in river rocks March 26th, 2019 April 4th, 2019
Continue construction Continue to build rainwater catchment system, keep adding to system and striving for excellence April 2nd, 2019 April 5th, 2019
Meeting with Lonny Have Lonny come look at the progress of the project and provide any feedback, feedback included getting rid of the wood pallet that the storage tanks were on April 9th, 2019 April 9th, 2019
Catch up with other groups Get updates and progress reports, help each other if possible and learn from one another to improve everyone's projects as much as possible to ensure a positive working/learning environment April 16th, 2019 May 1st, 2019
Finish presentation and Video Ensure that the video shows all attributes of the system and clearly communicates the project, the goal, and the design April 30th, 2019 May 13th, 2019
Work on Appropedia final draft Make sure formatting is clean, clear, and to the point April 30th, 2019 May 13th, 2019
Wrap-up construction and finishing touches Make sure that the project works and is completed to the best of the teams abilities May 7th, 2019 May 15th, 2019


Rainwater falls on the greenhouse roof and runs down to the gutter, where it is collected and diverted towards the storage containers. Before it gets to the storage tanks the water falls onto a screened funnel that filters out larger debris and concentrates the flow down the conveyance system. Next, the water falls into the first flush which fills with the first and most polluted portion of the rainwater. The first flush contains a ping pong ball and as it fills, the ping pong ball rises and then plugs the opening, sealing the first flush and allowing the water to then flow into the storage tanks. The water will then fill the storage tanks (which are connected by a pipe at the bottom, so they fill at equal speeds) and become accessible to the grounds staff at CCAT.


Costs for materials bought throughout the project that were required to complete the project to best of our ability.

Quantity Material Source Cost ($) Total ($)
2, 10ft pieces ABS pipe Ace 11.99 23.98
5 Fittings, Elbows, Spicket Ace 4.50 22.50
1 Storage Tank. Two 50 Gal fixing leaking CCAT Donation, Ace 15.00 25.00
1 First Flush Materials (Cap, ball, ABS Glue) Ace 20.00 20.00
1 Filter&Funnel CCAT Donation, Ace 5.00 5.00
2 Gutter, Fix Leaks, gutter tape CCAT Donation, Ace 20.00 40.00
1 Silicon Hamanaka Painting Donation Donation
1 Nails CCAT Donation Free Free
1 Aesthetics TBD 10.00 10.00
Total Cost $146.98


System should be inspected every few months to make sure that there are no leaks. If the system has any holes the water will find them and make them apparent.

Make sure that the screen over the funnel is cleaned off whenever there is a large amount of debris of leaves covering the screen. If the screen gets covered, it makes it harder for the water to make its way to the first flush, through convenience and ultimately to the storage units.

Check gutters for any plant matter, such as twigs, sticks, and leaves, to make certain that all the water you are catching can make it's way uninterrupted through the system.


The process of conceptualizing, designing, and implementing this rainwater catchment system has been… a time. Looking back, there are many things we would have done differently. That being said, we are proud of the work that was done and approve of the system in place today. If we were to reconstruct this system, we would ensure our gutter system is correctly assembled (or better yet have the gutter be one continuous piece) and angled before officially attaching it to the Greenhouse. We also would have liked to use more solidified and standard rainwater catchment tanks. Our tanks were based out of up-cycled pickle barrels that took more effort in transforming than we had anticipated. This brings us to what the next steps are for this system. Make sure the system is inspected regularly for leaks and clogging. The funnel at the top of the conveyance system will need to be periodically cleaned and the first flush is detachable in order to allow future moderators to inspect it. Furthermore, there is a small leak where the first flush connects to the larger conveyance system that moderators should be aware of. Our main focus for this project was education, and we feel that we have provided a clear and practical understanding of rainwater catchment systems.

Special Thanks

We want to thank Lonny Grafman for providing up with the in-person and literary education in order to complete this Rainwater Catchment System. Through their support and skills, we were able to easily and successfully catch the rain. Through their “To Catch The Rain” book, our project was defined through a step by step process as to how to construct, use, and maintain the system. We are proud to call ourselves Appropriate Technology students at Humboldt State University.


Kinkade-Levario, Heather Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse New Society Publishers, Jun 1, 2007

Grafman, Lonny To Catch The Rain Arcata. Humboldt State University Press, 2017

Mun, J.S. "Design and operational parameters of a rooftop rainwater harvesting system: Definition, sensitivity and verification" Eleviser Volume 93, Issue 1 (2012)