Rainwater harvesting methods and water catchment methods are another component of One Community’s open source project-launch blueprinting strategy for building a global collaboration of self-sufficient and self-sustainable teacher/demonstration communities, villages, and cities for the Highest Good of All. Rainwater catchment and harvesting will be incorporated into all seven different village models, the Duplicable City Center Hub, our sustainable food systems, and even our sustainable energy infrastructure. This page will function as the portal and hub for all of our water research, development, and ongoing open source project-launch blueprinting of duplicable rainwater harvesting methods, water catchment techniques, and swale building strategies.
We discuss this and more with the following sections:
NOTE: THIS PAGE IS NOT CONSIDERED BY US TO BE A COMPLETE AND USABLE TUTORIAL UNTIL
WE HAVE OUR PLANS PERMITTED AS PART OF THE CONSTRUCTION OF THE EARTHBAG VILLAGE.
AT THAT TIME WE WILL ADD HERE THOSE PERMITTED PLANS AND ANYTHING ELSE WE LEARNED.
IN THE MEANTIME, WE WELCOME YOUR INPUT AND FEEDBACK
Rainwater catchment, rainwater harvesting, and rainwater collection are all names for the collection and storage or rainwater. With proper filtration, this rainwater can be used for drinking and cooking. With minimal filtration it can be used for bathing, clothes washing, and dish washing. With no filtration it can be used for watering gardens and houseplants, flushing toilets, washing cars and buildings, composting, outdoor ponds and water features, fire control, etc.
The benefits of harvesting rainwater are many and we’d like to help more people experience these benefits. Collecting and using rainwater reduces municipal water needs and peak demands (demands on ground water), reduces costs/water bills, and is good for the environment. Proper harvesting also reduces flooding and erosion.
Open sourcing the rainwater catchment specifics for all seven different village models, the Duplicable City Center Hub, and our sustainable food systems is primarily for replication. It is also to help with open source collaborative improvement of the designs, as an example of the process and needs for other similar-sized structures, and to share here additional specifics like purchasing and installation details, the maintenance and upkeep process, etc.
SUGGESTIONS ● CONSULTING ● MEMBERSHIP ● OTHER OPTIONS
Daniela Andrea Parada: Civil Engineering Student
Matheus Manfredini: Civil Engineering Student specializing in Urban Design
As we continue open source project-launch blueprinting our water harvesting and catchment systems, build them, and problem solve and evolve them for One Community (and with others around the world) we will develop this page as the portal detailing open source and free-shared specifics related to this component including:
Water catchment will be a part of every structure we build and the list above will evolve into links with the related details on each individual structure page so we can organize, evolve, and share the details that people need to duplicate every aspect of this component of One Community in part or in whole.
Water catchment will be a part of every structure we build and the list above will evolve into links with the related details on each individual structure page so we can organize, evolve, and share the details that people need to duplicate every aspect of this component of One Community in part or in whole. Through our catchment strategies, One Community is confident that we can create an environment where we are capable of harvesting and storing more water than we use for daily living through this and other water conservation and catchment methods. This page explores this with the following sections:ugh a combination of water conservation and catchment methods. This page shares the following details:
As part of our commitment to Stewardship and Highest Good Living, the Pioneer Team will work to demonstrate maximum water efficiency and conservation. Below are some examples of what current average (A) versus conservative (C) water use looks like through conscientious practices applied to everything from taking a shower to reusing a drinking glass:
Looking at these numbers the average American uses around 50 gallons of water a day versus a more conservative approach only using 15-20 gallons! With a desire to demonstrate what is possible we are seeking maximally efficient appliances and designing warm and comfortable shower spaces to make practices like starting and stopping a shower to soap easy to do. We are also planning a separate “non-washing” hot waterfall experience (like a hot tub shower) for the ultimate experience of just standing in a huge volume of hot water and letting it run as long as a person likes without wasting any water.
Combining the calculations above we calculate a liberal 20 gallons of use per person X 365 days in the year = 7,300 gallons of water used per person each year. 339,892 gallons (see below) harvested off the earthbag village/7,300 gallons per person equals enough water for 46 people. Adding the water catchment from the Duplicable City Center City Hub (99,240 gallons), our sustainable food systems (136,555 gallons), and our solar panel array catchment (46,058 gallons) would provide enough water for an additional 40 people for a total of 86.
We are exploring additional water conservation approaches in an attempt to achieve 100% water self-sufficiency for all residents plus the additional 30% population of less conservation-minded visitors we will be hosting. All water not produced this way will be provided from on-site wells.
The earthbag village (Pod 1) is the first village model we will be building and the water catchment for the entire village has been calculated using the following color coordinated zones: yellow for domes, pink for patios, blue for roads & walkways, and orange for the Tropical Atrium.
Rainwater catchment for the dome homes would entail aggregating a gutter to each structure. Utilizing a gutter would create potential complications with the water, such as freezing. To avoid these obstacles, the domes are not designed to harvest water. Overall there are 82 domes with an external diameter of 18 feet and 4 domes with an external diameter of 28 feet.
Water catchment off the patio and stair areas (pink) of the dome clusters and has been calculated as follows:
The surface area of all the patios (pink) therefore equals (10 x 675) sq. feet + (6 x 269) sq. ft. = 8,364 sq. ft. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (8,364) X (.833) X (7.48) = 52,115 gallons of water harvested per year from the patios and stairways.
Water catchment off the primary roadway and walkways (blue) and has been calculated as follows:
The total surface area of all the roadways and walkways (blue) is 34,882 sq. feet. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (34,882) X (.833) X (7.48) = 217,344 gallons of water harvested per year from the patios and stairways.
Water catchment off the Tropical Atrium and surrounding walkway has been calculated as follows:
The total surface area of the Tropical Atrium (orange) is therefore 11,304 sq. feet. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (11,304) X (.833) X (7.48) = 70,433 gallons of water harvested per year from the patios and stairways.
*Note: For calculating cistern and pond sizes we used the average annual rainfall for our location of 13.6 ~ 15 in = average of 368.3 mm. For calculating pipe size we used the Daily Critical Rainfall (the maximum daily amount of rainfall in our location) of 1.3″ / 33 mm.
Here are the details of the water collection and transport system.
To determine the pipe sizes we needed:
To minimize the costs with excavations and soil removal, the slope of piping needs to be as minimal as possible without creating a potential water backup. The table at right shows the international standard for the minimum slope for each size of the pipe.
For most of the plumbing area we are using 2.5″ pipes, which ensure us with a 1/4″ slope. The radius of our village is ~170 feet minus 9 feet because our drainage won’t start right in the middle of the village. This gives us a drop of 41 inches for the international standard slope equal to 1/4″/foot associated with a 2.5″ pipe.
To calculate the discharge rate on each drain we need to know the catchment area (a) for each drain, the daily critical rainfall (b) and the coefficient of absorption of the soil (c).
Taking a critical storm that could last 1.5 hours, the maximum hourly amount can be rated as 1,500 gallons for each hour.
Looking at drains 9 and 10 (see below) as the 2 drains that receive the most amount of water, the estimated combined catchment area is ~2,500 square feet. This is lower than the safe drainage amount estimated for any one drain. This means we have an adequate safety factor.
Taking PVC as the material of the pipe, the roughness coefficient is 150.
The Earthbag Village consists of an outer ring of housing domes in addition to an inner ring. An elevation difference between the outer and inner domes influenced the design of the overall pipe systems because rainwater runoff must be collected from both the upper and lower surfaces. It is also for this reason that deep trenches will be used for the storm drain pipe network.
The storm drain pipe network is placed on the outermost edge of the roadway in order to keep pipe maintenance from blocking the entire use of the roadway. This reasoning is applied to the subsurface perforated pipe placed on the innermost edge of the road. Storm drain pipes were also placed surrounding the atrium and directed to the main system. The north and south entrances to the atrium incorporate catch basins for runoff water, in which its placement was based on the elevation changes in the immediate area.
Clean outs were placed into the design in order to ensure proper maintenance of the storm drain pipe network. These are openings in the pipes that allow for debris to be removed. The clean outs are placed at the pipe connections located on the outermost edge of the porous concrete roadway. The pipe connections within the 6 dome clusters and 3 dome clusters are not designed with clean outs. For those connections joining two pipes, a WYE connection is used. Though the installation of a junction box will be seen for connections of more than 2 pipes.
Each 6 dome cluster is designed to include two drains to collect rainwater runoff whereas the inner 3 dome clusters have one drain. In addition, 4 catch basins are placed at key points of the pipe networks. The flow of the runoff water is directed to both the East and West greywater ponds for the capture and cleaning of the runoff water. In the figure below, the drainage flow and the pipe network are illustrated clearly. Additionally, a 2 foot wide rock swale is incorporated into the outermost part of the roadway to collect additional runoff water when the road is fully saturated.
The pathways and walkways of Earthbag Village are composed of two main pavement types: decomposed granite and porous asphalt. Each material demonstrates qualities that are essential to the design and purpose of rainwater management. For instance, the patios to the outer ring domes are made of decomposed granite. This material is commonly used in xeriscaping as a result of its permeable abilities and low maintenance. The main roadway, a fire access road, is composed of porous asphalt. This material is classified as low impact development technology and grants efficient rainwater drainage while supporting a frequently used road.
The outer and inner ring of the main roadway is lined with an impermeable material. The impermeable liner keeps other elements or soils from infiltrating through the vertical plane and keeps water from seeping through.
As the drain rock depth is 27 inches, the impermeable liner covers this depth. An additional 6 inches of this material are also provided as a precautionary measure. Therefore the outer and inner rings of the main roadways each have an impermeable liner that reaches 33 inches in depth. The geotextile material on the other hand is laid parallel with the horizontal plane. The geotextile is placed prior to the drain rock. This material is permeable and will therefore allow water to filter through. Geotextiles are commonly used to improve soil characteristics and reinforce layers of different soil types. As mentioned previously, 27 inches of drain rock is placed above the geotextile, yet another sheet of the geotextile may be placed on top of the drain rock if the design calls for the addition of another soil layer.
Water Catchment/Drainage Material Expenses of Earthbag Village – Click for for the open source spreadsheet in a new tab
The calculations of the diameter of the pipes shall be done using the Hazen-Williams Formula, which includes the discharge rate, coefficient of the material and slope.
Calculations coming soon…
For cost and labor efficiency, the slope is the minimum determined to be effective. This reduces the needed excavation and the pond can be just ~2.3-2.5 feet under the ground level. For this reason in the AutoCAD drawing the slope is a little bit difficult to be seen.
The minimum pond size for the large pond shown below is 16′ diameter and 9 feet deep.
Calculations coming soon…
Water collection (with storage in the central pond) is planned for the Aquapinis, Walipinis, and surrounding roadways. Water catchment for this area has been calculated using the following color coordinated zones: Pink for small structures, Orange for the large structures, and Blue for Roads & Walkways.
Food Infrastructure Water Collection Zones: Click to Visit the Aquapini and Walipini Open Source Hub
The water collection area of each small structure (pink) equals 2079 square feet x 4 structures = 8,316 sq. ft. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (8,316) X (.833) X (7.48) = 51,885 gallons of water harvested per year from these structures.
The water collection area of each large structure (orange) equals 3,399 square feet x 2 structures = 6,798 sq. ft. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (6,798) X (.833) X (7.48) = 42,357 gallons of water harvested per year from these structures.
The water collection area of the walkways and central area equals 6,791 sq. ft. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (6,791) X (.833) X (7.48) = 42,313 gallons of water harvested per year from this area.
*Note: For calculating cistern and pond sizes we used the average annual rainfall for our location of 13.6 ~ 15 in = average of 368.3 mm. For calculating pipe size we used the Daily Critical Rainfall (the maximum daily amount of rainfall in our location) of 1.3″ / 33 mm.
Water will also be collected off the entire Duplicable City Center Hub. Water catchment for this area has been calculated using the following color coordinated zones: Pink for the domes and Blue for the central area. There is a 4th floor cupola that will cover the central area but water will still be collected from this cupola so we have used the zones you see below for simplicity.
The Duplicable City Center footprint for each of the domes (area of the circle) was calculated for rainwater catchment. The area of a 74′ diameter circle equals 4,300 feet x 3 domes = 12,900 sq ft. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (12,900) X (.833) X (7.48) = 80,485 gallons of water harvested per year from the domes.
Note: For those interested, the actual surface area of each of the Duplicable City Center’s 74′ diameter/35′ high domes (pink) can be quickly calculated using this tool as equalling 8,149 feet.
The area of the central water collection zone (blue) for the Duplicable City Center includes the area shown on the map above (topped with the cupola that will cover much of this area) equaling roughly 3,010 sq ft. of rain collecting space. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (3,010) X (.833) X (7.48) = 18,754 gallons of water harvested per year from the Duplicable City Center Hub.
*Note: For calculating cistern and pond sizes we used the average annual rainfall for our location of 13.6 ~ 15 in = average of 368.3 mm. For calculating pipe size we used the Daily Critical Rainfall (the maximum daily amount of rainfall in our location) of 1.3″ / 33 mm.
Water will also be collected off of and under our energy infrastructure of solar panels that will cover a total of 7,392 square feet. Using a (conservative for our location) 10-inch annual rainfall* and applying the formula for calculating water harvesting (catchment area x rainfall x runoff) yields: (7,392) X (.833) X (7.48) = 46,058 gallons of water harvested per year.
*Note: For calculating cistern and pond sizes we used the average annual rainfall for our location of 13.6 ~ 15 in = average of 368.3 mm. For calculating pipe size we used the Daily Critical Rainfall (the maximum daily amount of rainfall in our location) of 1.3″ / 33 mm.
Swale creation is part of the One Community water conservation plan, stewardship strategy, and food forest design. In addition to water collection off all the structures of One Community, we will also open source project-launch blueprint the effectiveness and value of swale creation for land restoration, food forest establishment and support, and greywater processing.
Tamera Eco-Settlement Water Conservation Results: This Took Less Than 4 years
A swale is a ditch and berm system designed to halt overland water flow and maximize water infiltration. The design calls for an excavated ditch along the contour lines of a property such that the ditch is always following the level contour of the land. The soil excavated from the ditch is moved to the downslope side to form a berm. It is important to make sure that the top of the berm is level, in order to prevent accumulated water in the swale from finding a low spot and washing out the berm. The entire area is raked smooth, mulched, and densely planted with a broad mix of annual and perennial species. In dry climates it may be necessary to irrigate the plantings until the first rain event, or until the plantings take hold.
A properly designed and constructed swale accomplishes a number of important functions. First and foremost is the retention in the landscape of the maximum amount of precipitation or inflow. As the infiltrated water moves down and out through the soil profile, it enables the growth of trees and other plants upslope and downslope of the swales that would not otherwise survive on the site. The tree cover in turn shades and mulches the swale, maintaining and enhancing the infiltration; as the trees grow, their roots help guide moisture ever deeper into the soil profile. This synergistic feedback loop makes possible the reforestation or afforestation of even the driest regions. The system is expanded with additional swales upslope and downslope across the landscape.
It is important to understand that a swale is NOT meant to direct or divert the flow of water across the slope. Rather, the design and intention of a swale is to HALT the flow of water, so that it collects in the swale and has the chance to sink into the soil. In areas that receive sufficient rainfall, swales can be connected to a series of deeper ponds or impoundments to hold larger amounts of water. These can be constructed to increase the area of infiltration, or designed as permanent ponds.
Understanding the soil structure where a swale is under consideration is important to achieve the aim of maximum infiltration. On most soils, the mulch layer starts the generation of the soils microbiota, which improves the crumb structure and drainage of the soil. In the case of clay, treatment with gypsum (calcium sulfate) followed by mulch, will help the clay flocculate and achieve percolation. In extremely rocky or shale situations, mechanically ripping the bottom of the swale with a dozer shank may be necessary.
As a swale establishes its associated habitat, an accelerated turnover in species composition is seen. The initial annuals and short-lived perennials are soon shaded out by taller, longer-lived trees and shrubs, which in turn are succeeded by slower growing climax forest species. At each stage of this evolution, niches are created for new species, and “edge” increases at the peripheries. Properly managed, each of these niches is an opportunity for developing an ever-widening array of yields.
As the systems of multiple swales extend towards each other, the management of the interswale zone can be maintained as e.g. open meadow, agricultural field, home or village site, etc. Allowing these sites to be surrounded with swale-derived agroforest increases their soil moisture, reduces wind and evapo-transpiration, provides convenient access to wild foods, medicinal plants, and other forest yields. This approach brings Zones 3 and 4 closer to Zones 1 and 2.
Forming swales looks like this:
A swale on contour catches large volumes of water and allows it to soak into the land like this:
Water caught by a swale absorbs into the land like this:
Ripping plow lines on contour, pushes rushing water from the valleys out to the ridges like this:
Excess water from swales is directed to ponds and lakes like this:
Bamboos are an especially useful set of plants for swales. Monopodial (“clumping”) bamboos have very dense root systems, and excel as silt traps. The sympodial or so-called “running” bamboos spread out and form groves of canes that can quickly shade and mulch large areas. Their root systems will seek moisture, and they can spread along a swale for hundreds of feet, mulching and protecting the newly installed swale as they go. Near dwellings or settlements, all greywater can be directed to bamboo groves, which will greedily filter out nitrates and nitrites. There are different species of bamboo that will grow from the equator to the arctic latitudes, and given the wide variety of yields – edible shoots, medicine, craft and construction wood, mulch, fuel, livestock browse, etc. – their judicious selection and placement should be part of any site development.
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