Difference between revisions of "Natural Water System - Drainage and Harvesting"

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We are using a retention/drainage field in the front, parking area and backyard area to retain water and allow it to infiltrate into the water table.  These areas would be planted with native species that like the water and have properties that cleaning the water before it enters the water table.  The soil would be be designed with courses that provide adequate drainage capacity.  Our current design is for the following courses:   
+
We are using a retention/drainage field in the front yard area, parking area and backyard area to retain water and allow it to infiltrate into the water table.  These areas would be planted with native species that like the water and have properties to clean the water before it enters the water table.  The soil would be designed with courses that provide adequate drainage capacity.  Our current design is for the following courses:   
 
* The Parking Area and Front area courses would be:
 
* The Parking Area and Front area courses would be:
 
** Brick / Crushed stone (3.5")
 
** Brick / Crushed stone (3.5")

Revision as of 19:33, 26 June 2009

return to Living Building Design Studio

What is It?

Water cycle.jpg

This is fundamentally about our stewardship of the water in the natural water system, which is vital to our sustainability. Today, by code, the rain that falls on the Green Garage building and site is required to be retained on the site or placed in the storm drains. These storm drains run into our rivers and lakes, bypassing the natural cleaning system of the wetlands and percolation into aquifers. By all accounts this is destroying our lakes and rivers. A recent study showed it will take $2 billion to clean up the Great Lakes and the EPA has cited urban runoff, with its associated pollutants, as one of the top contributors to the decline in the health of our lakes.

This is about harvesting the water we need for plants and trees and returning the remainder to the water table cleaned for future generations. This requires an integrated drainage system to carry rain water off the building, storing some of it for future use and directing the remainder of it to drainage fields where it can be cleaned and absorbed into the soil, and eventually the water table. So the elements of this are:

  • Water Conversation ... reducing our demand for water
  • Green Garden Roof ... growing plants and food on the roof.
  • Roof drainage system ... how to get the rainwater off the roof.
  • Ground drainage system and percolation fields...how the water that falls on the ground and redirected from the roof will be returned to the water table.
  • Rain water storage (rain barrels, cisterns)...the rain water that is stored for use to water plants or flush toilets.



  • A brief description of what it is.
  • If it is part of a system-level pattern put a link to it in here.
  • Also known as:

Why is it Important?

Describe how it:

  • strengthen our understanding and relationship with water
  • helps restore the planet's natural water system and improve the quality of water for future generations
  • reduces the usage and associated costs of water from the public water system
  • creates One Earth patterns for water that others can use

When to Use It?

  • Virtually every built environment has a relationship with water that warrants special care.
  • The more roof our impermeable surfaces you have the more important this is.
  • Use water conservation methods first to reduce your demand for water
  • Storing water should only be used if there is a clear demand (i.e. use for the stored water.)


  • List the important considerations when to use this pattern.
  • When would it be sustainable?
  • When would it not be sustainable?

Green Garage Use of Natural Water System - Drainage and Harvesting

Sustainability Goals

  • Return 100% of the rainfall to the ground water table.
  • Capable of handling the volume of water generated by up to a 10 year storm event.
  • Clean the rain water before it re-enters the aquifer
  • Harvest rain water adequate to meet the watering needs of plants and trees on the Green Garage site.
  • Develop connections between people and the natural water cycle.
  • Use zero city supplied water for outside purposes


  • The specific goals we're trying to achieve. This should be the performance outcomes.
  • It doesn't describe how...just the outcomes.

Strategy

  • Determine how much rain falls in our area and what the storm water drainage requirements are for Detroit
    • 10 Year Daily = approx 3.0" of rain per day in Detroit
    • 25 Year Daily = approx 3.7" of rain per day in Detroit (see reference site here)
    • 100 Year Daily = approx 4.7" of rain per day in Detroit (see reference site here)
    • 100 Year Hourly = 2.75" of rain per hour in Detroit (per Michigan Plumbing Code)
  • Learn how the water flows on the current site and building
    • Create a water map showing how the water currently flows
  • Minimize the Demand for Water
    • Grow native plants and trees that clean the rain water and minimize the water demand.
  • Harvested Water Strategy
    • Harvest water for the plants in reused barrels and storage tanks
    • Store the harvested water close to where it will be used
    • Begin with a moderate amount of water stored and increase as the need arises
  • Percolation Field
    • Create a percolation field in the parking lot and front of the building where the demand for water is highest due to the sun and plants.
  • Building drainage
    • Move as much to the front as possible...this is where the sun is
    • Leave the storm drainage as a backup capacity, especially that in the truck well.
  • Overflow
    • Every retention and storage area will have an overflow into the public storm drains
    • The overflow will be placed before the storage and retention areas

Conceptual Design

Overall Design
Green Garage - Natural Water System: Drainage and Harvesting

The overall natural water system design is driven by the rain fall requirement. We set the rainfall requirement at 3 inch per day or 1 inch per hour. This is very close to what we can find out about the 15 year requirements (which needs confirmation...this is harder to do than we thought.)

Taking this requirement and our strategy (above) we developed the overall water drainage and harvesting design shown. change stromdrain to stormdrain on image

Rainfall Requirements Estimation
  • 10 Year Storm Requirements
    • Daily = 3.00in/ estimated from chart
    • Hourly = 1.00in/hr (needs confirming)

Detroit Monthly Precipitation (includes snowfall)

  • (Note that over a period of 57 years, 99.9% of the daily rainfall amounts have been less than 2").
Detroit Daily Precipitation - 1948 - 2005 US Climatology Historical Network


Detroit Monthly Precipitation Average Monthly 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
1.91" 	1.88" 	2.52" 	3.05" 	3.05" 	3.55" 	3.16" 	3.10" 	3.27" 	2.23" 	2.66" 	2.51"
TOTAL 32.89"
Detroit Monthly Precipitation Actual 2007 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
3.02" 	0.82" 	3.09" 	2.68" 	2.56" 	3.10" 	2.10" 	6.61" 	1.44" 	2.00" 	1.77" 	3.48"
TOTAL 32.67"
Detroit Monthly Precipitation Actual 2006 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
3.24" 	2.71" 	3.21" 	2.71" 	4.6" 	3.95" 	4.38" 	2.05" 	1.73" 	4.11" 	2.9" 	3.65"
TOTAL 39.24
Detroit Monthly Precipitation Actual 2005 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
3.40" 	3.02" 	0.74"	1.66" 	1.85" 	1.95" 	5.38" 	1.33"	1.63" 	0.13" 	4.70" 	2.52" 	
TOTAL 33.58"
Detroit Monthly Precipitation Actual 2004 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
1.43" 	0.63" 	3.29"	0.69" 	8.46" 	2.86" 	2.85" 	4.52" 	0.65" 	2.08" 	3.21" 	2.91" 	
TOTAL 28.31"
Detroit Average Monthly Snowfall 
JAN 	FEB 	MAR 	APR 	MAY 	JUN 	JUL 	AUG 	SEP 	OCT 	NOV 	DEC
11.9" 	9.3" 	7.0" 	1.7" 	Trace 	0" 	0" 	0" 	0" 	0.3" 	2.7" 	11.1"


  • Climatic Sources

NOAA's National Weather Service Weather Forecast Office

Storm Water Flow Maps
Area Natural Rainwater Flow on July 12, 2008


Roof Drainage

The roof drainage is currently designed to all go into the storm drains. Over the years the drains have stopped up and the owners at the time resorted to putting gutters on the building. These gutters have since seen their day and most have large holes.

Our new water plan, (see diagram), is to divide the roof into sections to have the water go to where it can be stored, used or placed into the drainage fields for the plants around to use.

Retention/ Drainage Fields

We are using a retention/drainage field in the front yard area, parking area and backyard area to retain water and allow it to infiltrate into the water table. These areas would be planted with native species that like the water and have properties to clean the water before it enters the water table. The soil would be designed with courses that provide adequate drainage capacity. Our current design is for the following courses:

  • The Parking Area and Front area courses would be:
    • Brick / Crushed stone (3.5")
    • Crushed stone bedding (2")
    • Crushed stone open-grade (4")
    • <<Any drainage pipe 12" and 4" would be laid here>>
    • Natural Stone open grade (16")
    • (Optional) geo-tex fabric
  • The Backyard courses would be:
    • Grass + Topsoil / Crushed stone (3.5")
    • Crushed stone open-grade (4")
    • <<Any drainage pipe 12" and 4" would be laid here>>
    • Natural Stone open grade (16")
    • (Optional) geo-tex fabric
Absorbtion Rates / Perc Tests

We are doing a percolation test on the site to determine the absorption rate of the soil. The results will be posted here when they are available. Our research indicates that the absorption rate of clay seems to vary a little depending on the source.

Clay Infiltration rates of:

Other Soil Type Infiltration Rates:

  • Sand: 1.5 - 6.0 inches/hour
  • Silt: 1/2 inch/hour


We performed a water absorption test in the backyard on June 22, 2009 to determine what type of soil we currently have. The following procedure is from the University of Wisconsin – Madison Arboretum site:

Perform the following infiltration test at each location selected.

  1. Dig a hole 6 inches deep by 6 inches in diameter.
  2. Fill hole with water and let stand for one hour.
  3. Refill hole with water. Measure depth of water with a ruler.
  4. Let stand 1 hour. Then measure the depth again.
  5. Use the following chart to determine soil types based on the rate at which water soaks into the soils.

The results of the test were:

Flickr Error ( Photo not found ): PhotoID 3654115041

Storage / Usage

Our current water harvesting plan calls for the following storage tanks:

  • 500 gallon tank on the side of the building near the truck well at 12 feet high. It will act at the water for the front of the building. The pressure will be approximately 20 psi (normal city water supply is in the 40 - 60psi range)
  • 2,500 gallon tank underground in the backyard near the alley (SE corner.) This would be used as a water source for the backyard plantings, the green alley plants, water to flush toilets and a community rainwater well.
  • Ten 55 gallon rain barrels. Most on the roof where the water would be needed most to water plants (e.g. flowering and food). Some rain barrels in the backyard near the compost bin for cleaning and watering plants.

We found little publicly available information about the water requirements of native plants exposed to natural watering. We feel the main plants needing water are on the roof garden and the alley. Our most current work is this:

  • Garden Beds Water Needs
    • Assumptions:
      • Native plants in the wild don't need to be watered. Then they can survive on on average of 3" a month in Michigan May - Sept.
      • Front Bed and front of Annex: because of the extreme heat island in the front of the buildings those areas will need 4" of rain per month.
      • The roof gardens will need 3" of water applied to the roots per month.
      • If we store the equivalent of one weeks need: 1" for the front and parking area and .75" for the alley and .5" backyard (obtained either from rain or gray water) the following shows the rain barrel need.
    • 1 Weeks Water Needs by Garden Area:
      • Front Bed: Area: 254 sq ft, Gals needed(1")= 159, Rain Barrels (55 gal): 3
      • Parking Lot: Area: 892 sq ft, Gals needed(1")= 555, Rain Barrels (55 gal): 10
      • Alley: Area: 744 sq ft, Gals needed(.75")= 349, Rain Barrels (55 gal): 6
      • Backyard: Area: 721 sq ft, Gals needed(.5")= 225, Rain Barrels (55 gal): 4
      • Roof Gardens: Area: 300sf, gals needed (2") = 375, Rain Barrels (55 gal): 6
    • If we can supplement the rainwater with steady supply source i.e. gray water, the storage size need could be reduced. (a half a week supply or a couple day supply)
    • Further Considerations:
      • Green Garage soil absorption rates
      • insulation around cement to decrease island heat effect?
Overflow

As indicated in our strategy we will have overflow connections to the public storm drain system at each downspout. It will connect into our existing storm drains in the building or in the truck well.


  • Describe how we plan to achieve these goals
  • Explain why we chose this specific strategy and design (our rationale)
  • Include pictures, drawings or videos(flickr)
Supporting science:

Proposed Materials / Suppliers

  • Identify (via links and short description) the materials and suppliers we propose to use.

Development Story

The Natural Water System - Drainage and Harvesting - Development Story page contains many images and videos documenting the process used at the Green Garage to design, build and operate our ?? system.

Related Internal Links

  • Help people find other related Green Garage pages that may help them. Keep it tight.

Resources


To Do's

return to Winter 2009 - Design Studio Sessions






  • Wash cars/bikes (homeless could do people's cars)
    • Use a wagon or hose to distribute water


Greywater

Greywater, What is It?

Any wastewater generated from non-industrial sources such as dishwashing, hand washing, bathing, and laundry is referred to as greywater. The wastewater that is generated by the flushing of toilets is considered blackwater. The distinction between greywater and blackwater is the concentration of toxic and biological contaminants, such as toxic chemicals and feces. Wastewater from kitchen sinks that contain large amounts of solid particles, wastewater containing high levels of toxic substances from household cleaning products, or wastewater from laundered diapers, can also be considered as blackwater. Greywater constitutes 50 to 80% of residential wastewater.

The conventional method of disposing greywater is to combine it with blackwater, and then direct it to septic tanks or sewers. This approach can result in system overloading. An additional shortcoming of this process is the contamination of the natural waters with poorly treated discharge. The later is especially true when sewage treatment facilities are burdened with storm sewer runoff during periods of heavy rain.

Solutions:

There are many re-uses for greywater. Diverting greywater for irrigation of landscaping and gardens are two possibilities, and with proper filtration and purification, the water can be re-used to flush toilets and for laundry purposes. There are claims that with high amounts of purification and decontamination of greywater, the resulting water can be potable, hence fit for human consumption. There are Do It Yourself (DIY) approaches and commercially available systems intended to treat greywater. Books and the Internet are good sources for information. A good system will deliver the best results in the proper context, with minimal maintenance and complexity. The ideal system should also have an overall positive environmental benefit.

Benefits:

The benefits of greywater re-use can be both ecological and economical. Foremost, there is a lowered demand for water extracted from natural sources. Because greywater can be used for irrigation, the small particles of food from kitchen sources also provide nutrients to the soil. Greywater returned to the earth is also effectively purified by the layers of soil as it permeates downward where it will replenish the water table. Returning greywater to the earth reduces the volume of water that will need to be treated by septic and sewage treatment plant systems, and the associated energy demands. The reduced reliance of city water for landscape and garden irrigation will also provide a cost savings to the occupants of the residence. A further benefit is choosing ecologically friendly cleaning and laundry products, which will increase demand, possibly resulting in lower costs and increased awareness of the impact of toxic cleaning products.

Concerns:

The greywater water can be sent to where it is needed by gravity, or by means of a pump. Precautions should be taken when the greywater is transported by a pump, as particulates and hair can foul the pump mechanism, prematurely ending the life of the pump.

Testing has shown that untreated greywater is considered to be a potential health risk and source of pollution, as the same types of micro organisms can be found as those which are present in blackwater (sewage), although at lower levels of concentration. The amount of risk of the spreading of disease becomes greater as the number of dwellings that share greywater re-use increases. Because of this concern, care should be taken not to consume unpurified greywater, or use it to irrigate any vegetables that may be consumed, especially un-cooked (raw). The best practice is to use greywater as irrigation of the soil surrounding vegetables and trees. This practice also minimizes risks of the spreading of micro organisms in an aerosol form when spraying and other forms of above ground distribution are used. As toxic chemicals can contaminate the soil, the proper choice of home cleaning products, laundry detergent, and other additives should be exercised. --Temp2009 15:13, 7 May 2009 (UTC)

Resources

  • From Wikipedia [1]
  • From Oasis Design [2]
  • United States; State Regulations Composting Toilets, Graywater Systems, and Constructed Wetlands, Compiled in 1999. [3]
  • Guidelines for Greywater Re-Use: Health Issues "a must read" [4]

Grey water systems

Soilb.jpg
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