Rainwater Harvesting Cistern Construction

Rooftop Rainwater Collection System Design

In a sequence of photographs here we describe a rooftop rainwater collection system that sends clean roof runoff into a very large masonry cistern built below a home in Guanajuato, Mexico. The building owners and system designers live atop a mountain where water is scarce and where water delivery by truck is both difficult and expensive.

This rainwater harvest system was designed by our (DF) friends David Pearson, PhD, a chemist and scientist, and Lynn Murphy, the property owners.

Bottom line: the water harvested from this roof is routed through collection barrels for plant watering or to a very large basement water storage cistern. This water is used for washing and bathing. When used for cooking or drinking it is further treated by filtration, ultraviolet light, and reverse osmosis. In periods of prolonged drought in Mexico the cistern may also receive water delivered by a tank truck.

Above we see a large low slope rooftop area that collects rainwater during the rainy season. Skylights, a rooftop access hatch, and a solar water heating system are also installed on this roof.

A masonry border or low parapet wall around the rooftop is penetrated at several drain locations to direct rainwater into pipes that in turn carry water to the basement cistern.

Screening (above) keeps eucalyptus leaves and other rooftop debris out of the piping. At initial rainfall water can be diverted away from the cistern so that water containing dust and bird droppings can be flushed from the roof and system before subsequent rainfall is diverted into the cistern itself.

Roof drainage is piped to a steel drum whose interior was cleaned and painted and filled with large rocks to absorb the shock of a heavy water flow into the system (below left).

The catch-drum outlet then directs water through the building's wall and into the rainwater storage cistern. The designers placed the drum outlet above its bottom to permit settlement of dust and debris that can be periodically removed.

A pump located in the cistern delivers water up to the building's various plumbing fixtures. At point of use in the kitchen where safe water potability must be assured, the owners installed a water purification system including a reverse osmosis treatment and a cascade of water filters (below).

This thoughtful rainwater catchment system in active use in a dry climate includes several interesting design features including the ability to have rain provide a rooftop dust flush before rainwater is diverted into the cistern and an extensive graywater collection system (orange arrows shown on the gray barrel at below left) that in parallel to the cistern conserves graywater for application to gardens and trees on the site.

A simple ball valve connected to the graywater container permits connection of a hose to direct graywater to where it is to be applied on nearby garden or trees.

More about graywater re-use systems is at GREYWATER SYSTEMS

Below, photos taken during original construction of this home show more details of this rainwater harvest and cistern storage system.

Above: the white pipe leaving the center of the front most rain barrel routes roof runoff into an enormous cistern located below the building's basement level floor.

Above and below, during construction, showing the entry to the rainwater storage cistern.

Below: a view in the cistern with some initial rainfall already collected.

Owners have to periodically empty this cavernous space for cleaning and algae removal.

For another very simple rainwater collection system see the rainwater collection and storage tank we show in our article

at PASSIVE SOLAR HOME, LOW COST and illustrated also at RAINWATER HARVEST STORAGE TANKS & CISTERNS

also designed for collecting as much rainwater as possible when rainy weather occurs.

Watch out: for clarity we emphasize that the rooftop rainwater stored in the basement cistern shown here is not used directly for drinking. The owners installed reverse osmosis systems and filters to provide safe, palatable drinking water. They do use this water for washing and bathing.

More on the potability question is at ROOFTOP RAINWATER SANITATION WARNING

Reader Question: Advice on building a traditional cistern

Our reader asked:

I have questions regarding very much older durable cisterns. First, my Grandfather's was partially below and partially above ground and it was round, maybe 8 ft across diameter. It collected water off his galvanized tin roof and gutters that passed through some very fine screens into the cistern.

I seem to recall that the liner for lack of a better word was use of something like the white very flat rectangular brick sort of like Fire Brick and probably concrete mortar but that is as much as I can recall. It was used for drinking water and just about everything. He just used a small galvanized bucket to drop and pull up the water.

The question is are there old designs of this type to be found somewhere. All I know is it worked fine and I loved the water out of it. This did not hit the ground so there was no, at that time, concern for harmful bacteria.

I suspect our air was much cleaner then too. Anyway, I really want to try to find out how his may have likely been built because I would like to try building one primarily for drinking use or cooking. I also plan to have no trees near the house so no big problem with leaves.

I do not recall any trees anywhere in the vicinity of his gutters or the cistern; they were all away from the house.

Can you help me with some information? Robert <raptor.1.robert@gmail.com> 6/24/2014 Robert

Reply: Cistern Specifications & Design Tips

Robert,

As we corresponded by email, cisterns are still used all over the world for water storage; in addition to keeping out debris, you may need to test (or sanitize) the water before using it for drinking.

Cisterns tend to be site-built of masonry, often open-topped or concrete-topped and may be above-ground or below ground.

Since traditional cistern construction is basically a masonry box lined with high-Portland cement to improve its water tight properties, we don't find many plans or design specifications. But I can list a few features you'll want to consider besides building the cistern box itself:

Photo: water delivery to a stone cistern located in the floor of a restaurant in San Miguel de Allende, Guanajuato, Mexico.

1. Cistern wall & bottom construction:
   
   walls need to be strong enough to withstand weather, earth pressure (if below ground), and thermal movement (if in a freezing climate where you'd need to protect from frost push).
2. Cistern top construction:
   
   must be strong enough to be perfectly safe against collapse or against someone falling in. A cistern constructed below a driveway, for example would need to be able to withstand heavy vehicle loading as well as earth cover loading and would also be at risk of contamination if a vehicle leaks oil or fuel in the area.
3. Cistern location:
   
   locating a cistern where it can be filled by rainwater can be a critical consideration in dry climates where rainwater storage is essential.
   
   Even where rainwater is not to be used to fill a cistern, if you are going to add water by delivery from a truck consider the requirement for convenient vehicle access. Traditional construction of cisterns in building basements is not my preferred design in new construction in northern climates if the cistern is going to contribute unwanted indoor moisture to the structure.
4. Cistern water entry, water outlets, and drainage:
   
   we may need to include four water connections, depending on cistern design and location:
   1. One or more water inlets
      
       to supply the cistern from a water source. Our friends David and Linn in Guanajuato cleverly designed their home's roof to collect rainwater and to direct it into a large cistern. The initial roof drainage is directed out of the cistern until dust accumulated on the roof has been washed away, then subsequent roof runoff is aimed into the cistern.
   2. Cistern water supply to the point of use:
      
      may be by gravity for uphill or rooftop cisterns, or may require a pump system.
      
      See PUMP, WATER PRESSURE BOOSTING for a type of pump and tank suitable for supplying water from a cistern.
   3. Cistern overflow: provide
      
       for directing excess water to a safe location that won't damage the building if cistern input (say from rainwater) has filled the cistern to capacity.
   4. Cistern drainage:
      
      for the purposes of cleaning or repair it may be necessary to empty the cistern.
5. Cistern inspection, entry, repair:
   
   most cisterns of large capacity include an access opening for inspection or repair.

I extend the "cistern" concept to include large plastic water tanks that are usually located above ground and sometimes on building roofs.

To consider the plastic tank alternative, see ROOFTOP WATER TANKS

More about using plastic tanks for water storage including possible health concerns associated with storing water in some types of plastic is

at PLASTIC RECYCLING CODES, TANKS, TYPES

Rooftop Rainwater Harvest Sanitation & Potability

Warning about Water Quality Concerns when using a Rainwater Water Storage Tank

Watch out: studies have shown that it's common to find bacterial contamination in drinking water retrieved from large closed water storage tanks, for example in the range of 2,500 gallons, and for people relying on water delivery to large water storage tanks, high levels of coliform bacteria was also found in samples taken immediately after delivery from a water truck. (Graham 2007) (Schafer 2012).

Campisano (2012) studied optimal rainwater storage capacity sizing based on the assumption that the water quality was such that the water use was restricted to flushing toilets where bacteria in the flush water is not the same health concern as in the research we cited above.

Therefore if you are intending to use rainwater for drinking, cooking, or possibly even bathing, you should test your water for contaminants, particularly bacteria, and most-likely you need need to install a water disinfection system.

See details at WATER TREATMENT EQUIPMENT CHOICES - home and also see UV ULTRAVIOLET LIGHT WATER TREATMENT 

Should I Test Rooftop Rainwater Harvest before Using on Food Crops or for Drinking?

Our reader Don asked:

I recently installed a food-grade rain barrel to catch water off my roof.

I was given the general caveat to test the water before using it to water the garden or various applications. All I could see would be what it picks up off the shingles. What tests should I do to know it is safe for irrigation? Laundry? - Don, 2026-08-01, posted originally at WATER TESTS for CONTAMINANTS 

Website editor/publisher's reply: rooftop rainwater harvest and water stored in cisterns or other large containers is not safe to drink: reasons & research

@Don,

Thanks that's a really interesting question. I'll cite some useful authoritative research on garden watering and general water quality of roof runoff at the end of this note.

Bottom line: rainwater harvested from a roof and stored in a large cistern is usually not safe to drink without disinfection and probably other treatments and that coliform and other contaminants are common in that water. (Schafer 2012) ( Adedeji 2014) (Graham 2005)

However I might not test the water if you're simply watering non-food plants.

Consider that if you didn't catch roof run-off water for re-use it'd be spilling on the ground around the building and, depending on the location of your garden or other plants, at least some of it would be running onto them anyway.

Watch out: I am absolutely NOT saying that roof runoff water is safe to drink. It's not.

Bird poop alone could make roof runoff a serious health hazard. And in the research I've reviewed and cited on this page you'll see that there are serious water quality and water safety (potability) concerns for water stored in cisterns or other large water storage tanks.

In addition SOME roofs might use older lead or zinc flashings whose runoff, while good at killing algae on the roof, is not something you'd drink.

Safer to Water Food-Crop Plants from below / at ground level: Don't Spray

Health experts recommend that such watering should be from below, that is, don't sprinkle aboveground crops, especially leafy vegetables like spinach or lettuce, with questionable water. I'm reminded of this with the current Cyclospora bacterial infection issues going on in the U.S. and note that some reporters have speculated (as do I, having seen it first hand) that some big factory-farm businesses taking over produce production including in Mexico may be watering those leaf-crops with already-contaminated water.

Bottom line: DO NOT drink roof runoff harvested rainwater directly nor use it in cooking without adequate sanitation / treatment.

But your roof runoff is most-likely perfectly safe for shrubs, flowers, trees, etc. (your "various applications") and for washing your car.

If you want to be careful, don't spray it onto leaf crop vegetables - better to water from the soil level. And if you or members of your household are at particularly vulnerable health risk you might test an occasional sample of the runoff for bacteria. I wouldn't bother to test for lead or zinc unless those are in materials on your roof.

Thanks for a great question. - Daniel Friedman

See more questions on the safety of rooftop rainwater harvest at CISTERN WATER SAFETY FAQs - safe to drink, bathe-in, water plants etc

Research on Rainwater Harvest & Cistern-Stored Water Potability

Reference citations for further reading below make it clear that experts have been considering this question, so it's certainly a reasonable one to ask, and some experts some strong caveats about roof runoff water, depending on how it's being used (particularly on potability). Using rainwater harvested for toilet flushing does not raise the potability concern and can also save more potable water for cooking and drinking and bathing.

Watch out: studies have shown that it's common to find bacterial contamination in drinking water retrieved from large closed water storage tanks, for example in the range of 2,500 gallons, and for people relying on water delivery to large water storage tanks, high levels of coliform bacteria was also found in samples taken immediately after delivery from a water truck. (Graham 2007) (Schafer 2012).

More about using large water storage tanks to harvest rainwater for toilet flushing is at LARGE CAPACITY WATER STORAGE TANKS.

• Artiola, Janick F., Channah Rock, and Gary Fix. WATER STORAGE TANK DISINFECTION, TESTING, AND MAINTENANCE [PDF] (2012). College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ) retrieved 2021/02/03 original source: https://repository.arizona.edu/bitstream/handle/10150/255333/az1586-2012.pdf?sequence=1
  Excerpts:
  
  The translucent material of these tanks will also allow sunlight to penetrate and can facilitate the growth of algae inside the tank.
  
  Warm water favors corrosion (Fig. 3), scale formation, and the growth of algae and other microorganisms.
• Barber, Richard, and Sean Barber. "Storage tank containing a black polyethylene inner layer." U.S. Patent 9,016,498, issued April 28, 2015.
  Abstract
  
  Black polyethylene storage tanks are an inexpensive and effective way to store water and simultaneously inhibit algae growth. However, based on other considerations, it may be desirable to use a storage tank with a non-black color.
  
  By producing a polyethylene water storage tank with a black inner layer and a non-black outer layer, the desire to inhibit algae growth and the desire to have a non-black exterior can both be met.
• Campisano, Alberto, and Carlo Modica. Optimal sizing of storage tanks for domestic rainwater harvesting in Sicily [PDF] (at sciencedirect.com) Resources, Conservation and Recycling 63 (2012): 9-16.
  
  Excerpt from Methodology:
  
  The typical scheme of a domestic rainwater harvesting system is based on the collection of rainwaters coming from the building roof (and/or other surfaces) and on their temporary storage within a rainwater tank.
  
  Under this scheme, demand for water uses in the house which are compatible with rainwater quality is satisfied primarily by water accumulated in the storage tank, and only then by water from the mains supply. In the present research, the demand was limited to the toilet flushing use and it was assumed to occur at a constant daily rate since toilet usage does not show large daily variability (Fewkes, 2000).
• Fewkes, Alan. "Modelling the performance of rainwater collection systems: towards a generalised approach." Urban water 1, no. 4 (2000): 323-333.
  
  Abstract excerpt: The collection of rainwater from roofs, its storage and subsequent use make a significant saving in the use of potable water. 
• Graham, Jay P., and James VanDerslice. The effectiveness of large household water storage tanks for protecting the quality of drinking water [PDF] (2005) (at IWA Publishing) Journal of Water and Health 5, no. 2 (2007): 307-313. - local backup saved as Large-Water-Tank-Water-Quality-Campisino.pdf
  
  Abstract: Many communities along the US-México border remain without infrastructure for water and sewage. Residents in these communities often collect and store their water in open 55-gallon drums.
  
  This study evaluated changes in drinking water quality resulting from an intervention that provided large closed water storage tanks (2,500-gallons) to individual homes lacking a piped water supply. After the intervention, many of the households did not change the source of their drinking water to the large storage tanks.
  
  Therefore, water quality results were first compared based on the source of the household's drinking water: store or vending machine, large tank, or collected from a public supply and transported by the household.
  
  Of the households that used the large storage tank as their drinking water supply, drinking water quality was generally of poorer quality.
  
  Fifty-four percent of samples collected prior to intervention had detectable levels of total coliforms, while 82% of samples were positive nine months after the intervention (p LESS THAN 0.05). Exploratory analyses were also carried out to measure water quality at different points between collection by water delivery trucks and delivery to the household's large storage tank.
  
  Thirty percent of the samples taken immediately after water was delivered to the home had high total coliforms (>10 CFU/100 ml). Mean free chlorine levels dropped from 0.43 mg/l, where the trucks filled their tanks, to 0.20 mg/l inside the household's tank immediately after delivery.
  
  Results of this study have implications for interventions that focus on safe water treatment and storage in the home, and for guidelines regarding the level of free chlorine required in water delivered by water delivery trucks.
  
  Excerpt from Discussion:
  
  Water in the large water storage tanks rarely had sufficient chlorine residual and was commonly contaminated with total coliforms. No statistically significant differences in drinking water quality, however, were detected between the time before the installation of the large storage tanks and nine months after.
• Manga, Musa, Timothy G. Ngobi, Lawrence Okeny, Pamela Acheng, Hidaya Namakula, Elizabeth Kyaterekera, Irene Nansubuga, and Nathan Kibwami. "The effect of household storage tanks/vessels and user practices on the quality of water: a systematic review of literature." Environmental Systems Research 10, no. 1 (2021): 18.
• Schafer, Cynthia A., and James R. Mihelcic. Effect of storage tank material and maintenance on household water quality [AWWA Journal] Journal‐American Water Works Association 104, no. 9 (2012): E521-E529. - local backup copy saved as Water-Tank-Water-Quality-Schafer.pdf
  
  Abstract: This study investigated water quality of household water storage tanks in Tiquipaya, Bolivia. Tank age has little effect on water quality. Storage tanks cleaned three or more times per year had statistically less Escherichia coli and turbidity than tanks cleaned less frequently (p = 0.10 and p = 0.06, respectively).
  
  There was a statistically significant difference between E. coli counts in tanks cleaned three or more times per year compared with storage tanks cleaned less than once per year (p = 0.01). Polyethylene tanks had statistically higher E. coli counts than fiber cement and fiberglass tanks (p = 0.10 and p = 0.17, respectively).
  
  Water temperatures reached their highest levels (34°C) in a black polyethylene tank and temperatures of 20 and 23°C in fiberglass and fiber cement tanks, respectively.
  
  Statistically significant increases in total coliforms and E. coli associated with an increase in temperature and a loss of chlorine residual were documented as water traveled from the treatment plant, through the distribution system, and into household cisterns and storage tanks (p values ranged from 0.02 to 0.05).
• Adedeji, Oludare H., Olufunmilayo O. Olayinka, and O. Olufunmilayo Micro pollutants in urban residential roof runoff environmental and health implications [PDF] (Academia.edu website) OSR Journal of Environmental Science Toxicology and Food Technology 8, no. 2 (2014): 55-63. - local copy saved offline as Micro_pollutants_in_urban_residential_roofs.pdf
  
  Abstract:
  
  This study assessed concentration of micro-pollutants (heavy metals- Cd, Cu, Fe, Mn, Pb, and Zn; organic compound – PAHs, pathogenic microorganisms) in ambient and harvested rainwater under urban residential rooftops. Samples were analysed using standard analytical procedures.
  
  Rainwater harvested from the rooftops were alkaline (8.5-9.6) compared to pH of 5.94 for the ambient rainwater. Conductivity ranged from 95.2 - 150.4 μS/cm due to the dissolution of deposited aerosols and leaching of roofing materials.
  
  Turbidity, Cu, and microbial counts (HPC, E. coli, TC and FC) exceeded the allowable limits for drinking water with inputs from the rooftops. C
  
  oncentration of Cu and Pb in harvested rainwater was higher than the WHO standards. Relative abundance of metals is as follows: Fe > Zn > Cu > Mn > Pb > Cd.
  
  Water quality from asbestos was the worst among the rooftops examined. Total PAHs was low ranging from 0.04 found in ambient rainwater to 0.18 in rusted galvanized iron sheet.
  
  All samples contain high amount of microbiological contaminants with the asbestos roofing sheet having TC and E. coli of 14000 and 12000 cfu/mL respectively. These can result in illnesses such as diarrhoea, urinary tract infections, respiratory illness and pneumonia.
  
  The study had shown that rooftops contributed significantly to contamination of harvested rainwater due to composition of roofing materials and age of the roof. Keywords: Ambient rainwater, atmospheric deposition, E. coli, harvested rainwater, micro-pollutants, PAHs, roofing sheets ...
  
  - and from the same paper Conclusion on p. 62
  
  Analysis of roof runoff show varying degrees of contaminant concentrations caused by leaching of roofing materials. The overall contribution of roofs to the contamination of roof runoff is significant for EC and TDS. Fe, Zn and Cu are the most serious pollutants in the roof runoff.
  
  Cu in the runoffs from rusted galvanized iron sheet and asbestos is higher than the WHO guideline. While there is low concentrations of total PAHs, roof runoff contains high amount of microbiological contaminants, which are above the recommended limits for drinking water.
  
  The study revealed that roof runoff is a potential source of nonpoint pollution because roofs typically make up a significantly proportion micro-pollutants which are detrimental to health and hygiene. Using less of materials associated with identified pollutants would reduce pollution from runoff. Harvested rainwater needs treatment before potable use to reduce high rates of sickness and mortality from preventable water-related diseases.
• Chang, Mingteh, Matthew W. McBroom, and R. Scott Beasley. "Roofing as a source of nonpoint water pollution." Journal of environmental management 73, no. 4 (2004): 307-315.
• Chaplot, V., M. S. Selala, H. Thenga, and G. P. W. Jewitt. "Comparison of the chemical quality of rainwater harvested from roof and surface run-off systems." Water SA 44, no. 2 (2018): 223-231.
• Eisner, Neil. METHOD FOR INHIBITING ALGAE GROWTH IN WATER TANKS AND APPARATUS THEREFOR [PDF] U.S. Patent 7,118,700, issued October 10, 2006.
  Abstract
  
  A method of inhibiting the growth of algae and like organisms in plastic water tanks exposed to sunlight comprises providing an outer tank surface operative to reflect off a substantial portion of sunlight that hits the tank off the outer tank surface; and providing an opaque inner tank layer operative to substantially prevent sunlight passing through the outer tank surface from entering an interior of the tank.
  
  A two layer tank is provided comprising a light colored outer layer and a dark sun-blocking inner layer, and is conveniently made by a rotational molding process.
• Gikas, Georgios D., and Vassilios A. Tsihrintzis. "Assessment of water quality of first-flush roof runoff and harvested rainwater." Journal of Hydrology 466 (2012): 115-126.
• Igbinosa, Isoken Henrietta, and Isoken Tito Aighewi. "Assessment of the physicochemical and heavy metal qualities of rooftop harvested rainwater in a rural community (full text at Wiley online library) Global Challenges 1, no. 6 (2017): 1700011.
  
  Conclusion:
  The quality of rooftop harvested rainwater sampled in Ugbihioko, a rural community near Benin City, revealed that some parameters were within the permissible limit recommended by the World Health Organization's Potable Water Guidelines.40 Roof harvested rainwater quality appears to be linked to the location of the rooftop harvested rainwater systems. In some instances, environmental factors have a negative effect on rooftop harvested rainwater quality, as was observed in the present study.
  
  Public education of the hazards associated with the consumption of untreated rooftop harvested rainwater is needed. More so, these water systems can be reservoirs for pathogenic microbes that are harmful to human health.
  
  Advanced studies on rooftop harvested rainwater are needed to analyze the role of roofing materials and collection systems on the variability of heavy metal concentrations. Water quality treatment of rooftop harvested rainwater in homes that rely exclusively on this water for drinking and domestic uses is highly recommended.
• Lye, Dennis J. "Rooftop runoff as a source of contamination: A review." Science of the total environment 407, no. 21 (2009): 5429-5434.
  Abstract
  
  Scientific reports concerning chemical and microbiological contaminant levels of rainwater runoff from rooftop collection in both urban and rural areas are reviewed. This alternative source of water has been documented to often contain substantial amounts of contaminants.
  
  Studies describing levels of heavy metal contamination specific to runoff from rooftop catchment areas containing exposed metal surfaces are discussed.
  
  Depending upon the intended use, scientific evidence is also accumulating that various treatments and disinfections will be required prior to release of roof-runoff water either into surface waters or for more direct consumer usage.
  
  For microbial contamination, current proposed standards and guidelines regarding this type of water source are shown to vary widely worldwide. Scientific literature reveals a lack of clarity regarding water quality guidelines and health related standards for certain types of rooftop runoff.
  
  Studies suggests that rainwater collection systems which are properly designed, maintained, and treated may provide a valuable supplement to existing water supplies by reducing demand on community water supplies/infrastructure costs, enhancing effective management of storm water runoff, and increasing restoration of underground ...
• Schafer, Cynthia A., and James R. Mihelcic. Effect of storage tank material and maintenance on household water quality [AWWA Journal] Journal‐American Water Works Association 104, no. 9 (2012): E521-E529. - local backup copy saved as Water-Tank-Water-Quality-Schafer.pdf
  
  Abstract: This study investigated water quality of household water storage tanks in Tiquipaya, Bolivia. Tank age has little effect on water quality. Storage tanks cleaned three or more times per year had statistically less Escherichia coli and turbidity than tanks cleaned less frequently (p = 0.10 and p = 0.06, respectively).
  
  There was a statistically significant difference between E. coli counts in tanks cleaned three or more times per year compared with storage tanks cleaned less than once per year (p = 0.01). Polyethylene tanks had statistically higher E. coli counts than fiber cement and fiberglass tanks (p = 0.10 and p = 0.17, respectively).
  
  Water temperatures reached their highest levels (34°C) in a black polyethylene tank and temperatures of 20 and 23°C in fiberglass and fiber cement tanks, respectively.
  
  Statistically significant increases in total coliforms and E. coli associated with an increase in temperature and a loss of chlorine residual were documented as water traveled from the treatment plant, through the distribution system, and into household cisterns and storage tanks (p values ranged from 0.02 to 0.05).
• Also see CLEANING & DINSINFECTING WATER CISTERNS AFTER FLOODS & HEAVY RAINS [PDF] U.S. CDC

Cistern Construction For Rainwater Harvesting Research & Guides

• See also CISTERN RESEARCH & DESIGN / USE MANUALS - separate reference liset
• Ali, A., T. Oweis, A. B. Salkini, and S. El-Naggar. "Rainwater cisterns: traditional technologies for dry areas." ICARDA, Aleppo, Syria. iv (2009).
• Campisano, Alberto, and Carlo Modica. Optimal sizing of storage tanks for domestic rainwater harvesting in Sicily [PDF] (at sciencedirect.com) Resources, Conservation and Recycling 63 (2012): 9-16.
  
  Excerpt from Methodology:
  
  The typical scheme of a domestic rainwater harvesting system is based on the collection of rainwaters coming from the building roof (and/or other surfaces) and on their temporary storage within a rainwater tank.
  
  Under this scheme, demand for water uses in the house which are compatible with rainwater quality is satisfied primarily by water accumulated in the storage tank, and only then by water from the mains supply. In the present research, the demand was limited to the toilet flushing use and it was assumed to occur at a constant daily rate since toilet usage does not show large daily variability (Fewkes, 2000).
• Edwards, D., and K. Keller. 1984. A Workshop Design for Rainwater Roof Catchment Systems (Training Guide) and Appendix: Rainwater Harvesting for Domestic Water Supplies in Developing Countries. La Paz, UNESCO/ROSTLAC, UNICEF, Instituto de Hidráulica e Hidrología.
• Gnadlinger, Joao. "Lime—the great sealer: constructing low-cost, sub-surface rainwater tanks in Brazil." Waterlines 14, no. 2 (1995): 11-14.
• Gould, J.E. 1990. "Development of Rainwater Catchment Systems: Technology and Implementation Strategies in the 1980's and Lessons for the 1990's." In: Experiences in the Development of Small-Scale Water Resources in Rural Areas: Proceedings of the International Symposium on Development of Small-Scale Water Resources in Rural Areas, Bangkok, Carl Duisberg Gesellsehaft, South East Asia Program Office, pp. 95-105.
• Gould, John E. "The Fourth International Rainwater Cistern Systems Conference." Waterlines 8, no. 2 (1989): 31-31.
• Gould, John E. "The Rain-water Cistern Systems Conference in Thailand." Waterlines 6, no. 2 (1987): 12-13.
• Graham, Jay P., and James VanDerslice. The effectiveness of large household water storage tanks for protecting the quality of drinking water [PDF] (2005) (at IWA Publishing) Journal of Water and Health 5, no. 2 (2007): 307-313. - local backup saved as Large-Water-Tank-Water-Quality-Campisino.pdf
• Hadwen, P. 1987. "Caribbean Islands: A Review of Roof and Purpose Built Catchments." In Non-Conventional Water Resources Use in Developing Countries. New York, United Nations, pp. 455-468. (Natural Resources/Water Series No. 22).
• Haebler, R.H., and D.H. Waller. 1987. "Water Quality of Rain Water Collection Systems in the Eastern Caribbean." In Proceedings of the Third International Conference on Rainwater Cistern Systems. Khon Kaen, Thailand, Khon Kaen University.
• Hasse, Rolf, Rainwater Reservoirs Above Ground Structures for Roof Catchment: Most Common Rainwater Tanks in Comparison and Construction Manual,
  
  may be helpful to people constructing rainwater collection and reservoir systems for use in arid climates such as Mexico and the U.S. Southwest.
• HU, Wen-wu, Ping JIANG, Wei-zhong AI, and Song-ling SUN. "Research on wireless farming cistern control system based on self-study mechanism [J]." Electronic Design Engineering 4 (2010): 003.
• Ikebuchi, Shuichi, and Seiji Furukawa. "Feasibility Analysis of Rain Water Cistern Systems as an Urban Water Supply Source." In Proc. Rain Water Cistern Systems Conf, pp. 118-127. 1982..
• Junker, M. 1995. Abastecimiento de Agua Potable en los Asentamientos Indígenas de Diez Leguas. Filadelfia, Paraguay. Dirección de Recursos Hídricos de Paraguay e Instituto Federal de Geociencias y Recursos Naturales de Alemania. (Cooperación Hidrogeológica Paraguayo-Alemana, Informe Técnico N°1)
• Kinkade-Levario, Heather, Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse, .

  Outlines the process of water collection from multiple sources-landscape, residential, commercial, industrial, school, park, and municipal systems Provides numerous case studies, Details the assembly and actual application of equipment, Includes specific details, schematics, and references.

  All aspects of rainwater harvesting are outlined, including passive and active system setup, storage, storm water reuse, distribution, purification, analysis, and filtration. There is even a section on rainwater harvesting for wildlife.

  In addition to rainwater, there are several affordable and accessible alternate sources, including cooling tower bleed-off water, air conditioning condensate, gray water, and fog collection. Design for Water is geared to providing those making development decisions and guidelines with the information they need to set up passive harvesting techniques.

• Krämer, S. "Improving the Construction of Cisterns in Yemen and the Cistern Water Quality." Fachhochsschule Giessen Friedberg, University of Applied Sciences (2003).
• König, Klaus W., and Dietmar Sperfeld. "Rainwater harvesting—A global issue matures." Sustain. Water Manag 1 (2007): 31-35.
• Lye, Dennis J. "Microbiology of rainwater cistern systems: A review: (Cistern, Rainwater, Microorganisms)." Journal of Environmental Science & Health Part A 27, no. 8 (1992): 2123-2166.
• Macomber, Patricia S.H., Guidelines on rainwater catchment systems for Hawaii, CTAHR resource management

  This more technical document may be especially helpful for rainwater collection and recycling systems for climates where there is heavy rainfall such as demonstrated for Hawaii.

• Nissen-Petersen, Erik & John Gould, Rainwater Catchment Systems for Domestic Supply: Design, Construction and Implementation,

  ... the art of roof and ground catchment systems for rainwater. The water collected can be used for household or other purposes. The designs are aimed for individuals with limited access to electricity and/or civic water utilities. The text includes drawings, photographs and step-by-step instructions.

• OXFAM, RAIN WATER HARVESTING GUIDELINES [Website article] (2013), OXFAM, Technical Brief, (OxfamWASH.org is created by the WASH team, a part of Oxfam’s Global Humanitarian Team.) local backup copy saved as Rain-Water-Harvesting-Guidelines-OXFAM.pdf [Oxfam is an international confederation of 21 independent non-governmental organizations (NGOs), focusing on the alleviation of global poverty, founded in 1942] - Wikipedia
  
  Excerpt:
  The purpose of this guideline is to collate and document existing knowledge, information and practical experience on rainwater harvesting, in order to have it readily accessible/available to be used as reference material for Oxfam’s humanitarian, disaster risk reduction and sustainable livelihood programmes.
  
  Note: this is one of the more complete and useful references we found on this subject - Daniel Friedman, InspectApedia.com
• Patel, I. Pravin, and II Rajesh Dhore. USE OF GEOSYNTHETICS IN WATER HARVESTING [PDF] Proc. of The Third Intl. Conf. on Advances in Civil, Structural and Environmental Engineering - ACSEE 2015 ISBN: 978-1-63248-065-1 doi: 10.15224/ 978-1-63248-065-1-89
  
  Keywords— Geosynthetics, rainwater, water harvesting, recharging, stram water drain, water logging, recharge-pit.
• Patel, I. Pravin, and II Rajesh Dhore. USE OF GEOSYNTHETICS IN WATER HARVESTING [PDF] Proc. of The Third Intl. Conf. on Advances in Civil, Structural and Environmental Engineering - ACSEE 2015 ISBN: 978-1-63248-065-1 doi: 10.15224/ 978-1-63248-065-1-89
  
  Keywords— Geosynthetics, rainwater, water harvesting, recharging, stram water drain, water logging, recharge-pit.
• Silva, A. de Souza, and E. Rocha Porto. 1982. Utilização e Conservação dos Recursos Hídricos en Areas Rurais do Trópico Semi-árido do Brasil. Petrolina, PE, Brazil, EMBRAPA-CPATSA. (Documento No. 14)
• -----, et al. 1984. Cisternas Rurais. Dimensionamento, Construção e Manejo. Petrolina, PE, Brazil, EMBRAPA-CPATSA-SUDENE. (Circular Técnica No. 12)
• -----, et al. 1988 Captação e Conservação de Água de Chuva no Semi-árido Brasileiro: Cisternas Rurais. II. Agua para Consume Humano. Petrolina, PE, Brazil, EMBRAPA-CPATSA. (Circular Técnica No. 16)
• Smith, Henry H. 1983. Effects of Various Factors on the Sizing of Rain Water Cistern Systems. #2 John Brewers Bay, St Thomas, College of the Virgin Islands, Caribbean Research Institute. (Technical Report No. 19)
• Solomon, Hossana, and Henry H. Smith. "Effectiveness of Mandatory Law of Cistern Construction for Rainwater Harvesting on Supply and Demand of Public Water in US Virgin Islands." In Seventh Caribbean Islands Water Resources Congress, p. 75. 2007.
• Still, Gwilym T. Y Terry Thomas, THE OPTIMUM SIZING OF GUTTERS FOR DOMESTIC ROOFWATER HARVESTING [PDF] (2002) DTU, Domestic roofwater Harvesting Research Programme, School of Engineering, University of Warwick, retrieved 2023/05/04, original source: rainharvest.com/more/Optimize-Gutter-Rain-Retrieval.pdf
  
  Abstract excerpt:
  
  Guttering, in a roofwater harvesting system, has the purpose of intercepting the roof run-off and conveying it to a downpipe (which in turn carries it to a store). The two phases of ‘interception’ and ‘conveyance’ make different and sometimes conflicting demands upon a guttering design.
  
  Their respective failures (overshoot and overflow) occur under similar circumstances, namely intense rain, and for most analytic purposes it is appropriate to consider as total water loss just the higher of the overshoot loss and the overflow loss, rather than their sum. A
  
  good gutter design must satisfy many criteria including durability, cheapness and ease of fixing. In this paper on gutter sizing, the primary approach is to find that gutter size and shape that maximises the ratio of water benefit to system cost.
• United Nations. Department of Technical Cooperation and Development. 1989. Roof Catchments, Roof Coverings, Guttering and Downpipes. New York. (United Nations Water Resources Assessment and Planning in Pacific Islands; UNDP Project RAS/87/009)
• Vincent, Linden. The politics of water scarcity: irrigation and water supply in the mountains of the Yemen Republic. Overseas Development Institute, 1990.
• Wahlin, L. "The family cistern: 3,000 years of household water collection in Jordan." In Ethnic Encounter and Culture Change. Papers from the Third Nordic Conference on Middle Eastern Studies, Joensuu, Finland, pp. 19-22. 1995.
• Waller, D.H. 1982. "Rainwater as a Water Supply Source in Bermuda." In Proceedings of the First International Conference on Rain Water Cistern Systems. Honolulu, University of Hawaii, Water Resources Research Center, pp. 184-193.
• Xiaozu, Yartg Zhijie Su. "Calculation of Rectangular Cistern on Winkler Elastic Foundation [J]." Special Structures 2 (2006): 011.
• Young, Edward S., and William E. Sharpe. "Atmospheric deposition and roof-catchment cistern water quality." Journal of environmental quality 13, no. 1 (1984): 38-43.
• Zhu,K, and L. Zhang, W. Hart, M. Liu, H. Chen, Quality issues in harvested rainwater in arid and semi-arid Loess Plateau of northern China, (out of print, find by search and deferred order). Amazon's description may be helpful:
  
  Loess soils cover vast areas in the arid and semi-arid regions of northern China. Due to the lack of reliable surface water and ground-water, rainwater harvesting has played a prominent role in farmers' domestic usage and agricultural irrigation. An economical and valid type of water storage cistern with optimum design of components has been introduced to rural areas in the Loess Plateau.
  
  Different collection alternatives showed apparent variations in rainwater quality. by using different catchments, such as mortar roofs and cement-paved courtyards, compacted land or road surfaces, rainwater can be effectively collected for storage in cisterns. This study focused mainly on the quality of rainwater harvested from the different catchment systems and stored for different periods of time.
  
  By analysis of the water samples stored in these cisterns, it was evident that rainwater quality could be improved significantly by self-purification during the storage.
  
  With emphasis on rainwater quality affected by the different catchment systems, it was found that the measured inorganic compounds in the rainwater harvested from roof-yard catchment systems generally matched the WHO standards for drinking water, while the concentrations of some inorganic compounds in the rainwater collected from land and road surfaces appeared to be higher than the guideline values for drinking water, but generally not beyond the maximum permissible concentrations.
  
  However, Fecal Coliform, which is an important bacteriological parameter for the three catchment systems, exceeded the limits of drinking water to a greater extend. Trace amounts of 55 organic pollutants were identified, including aliphatic hydrocarbons, aromatic compounds and phthalate esters, etc.
  
  The analytical results indicated that roof-yard catchments that included the ''first flush'' usually provided safe drinking water with low organic contents, even for rainwater collected immediately after rainfall. In contrast, rainwater harvested from road surfaces had poor quality with respect to the organic constituents, regardless of stored time.