Rainwater Harvesting for Landscape Irrigation

Presenters

Skip Graffam, RLA, LEED AP, ASLA

Nicole Holmes, PE, LEED AP BD+C

Heather Kinkade, RLA, LEED AP

Learning Objectives

Learning Objective 1 : Learn rainwater harvesting approaches for spray irrigation despite few clear standards

Learning Objective 2 : See how to work with local regulators to develop beneficial project-specific parameters

Learning Objective 3 : Explore potential risks and measures available to manage those risks

What is Rainwater Harvesting?

Collecting stormwater from impervious surfaces

and storing it for later use

A New Idea?

Capturing and re-using rainwater is not a new or complicated concept…

www.ens-newswire.com

Rainwater Harvesting Benefits

� Protect water resources

� Reduce stormwater runoff and pollution

� Reduce water/sewer bills ($$)

� Demonstrate sustainability

� Obtain LEED® Credits

Rainwater Harvesting Design Considerations

Capture

Reuse

Storage

Hydrology

Rainfall patternsCatchment area

CapacityTank size?Tank type?

Type and Frequency of use

Irrigation/seasonalToilet flushing /year-round

Rainwater Harvesting Design Considerations

Capture

Reuse

Storage

Water Quality?Catchment area Cover type and use

Maintenance?Pretreatment

Treatment?Filtration?

Disinfection?

Operational Risks?

Public Health and Safety Risks?

Environmental Concerns?

Pollutants In Stormwater

� Solids, Sediments, and Floatables� twigs, leaves, sand, dust, litter, particles

� Nitrogen and Phosphorus� fertilizers, detergents, plant debris, animal waste

� Petroleum hydrocarbons � oil and grease

� Metals� copper, lead, zinc, mercury, cadmium, chromium, and others

� Synthetic organics � pesticides, solvents, household and industrial chemicals

� Pathogens� bacteria and viruses

� Oxygen-Demanding Substances and Dissolved Oxygen� measured by Biochemical Oxygen Demand (BOD), Chemical Oxygen

Demand (COD), and Total Organic Carbon (TOC)

Rainwater Harvesting Risks

Operational Risks

� Course material blocking or damaging system

� Nutrients creating algal blooms and blocking irrigation equipment

� High iron levels and water hardness blocking irrigation equipment

Rainwater Harvesting Risks

Environmental and Public Health Risks

� Transporting unsafe levels of metals, chemicals, pathogens, and viruses

� Accidental ingestion of contaminated water leading to gastroenteritis

� Environmental damage to plants and soils

Rainwater Harvesting Considerations

Roofwater Collection:

� “Cleaner” water

� Minimal risk associated with reuse

� Pre-treatment recommended

� Disinfection of water typically not required

� Disinfection may be considered under certain circumstances (i.e sensitive populations, public interaction with water, bird droppings)

Rainwater Harvesting Considerations

Stormwater Collection (non-roof)

� “Dirtier” water

� Higher risk associated with reuse

� On-site access controls should be considered

� Pre-treatment and filtration recommended

� Disinfection of water recommended under most circumstances, particularly when on-site access controls are not possible

Rainwater Harvesting Considerations

Additional Considerations:

� “Do Not Drink” signs posted near supply taps

� On-site access control when irrigating

� Color-coded purple pipe or labeled “non-potable water – do not drink”

� Backwater valve to protect public water supply

� Frequent inspection and maintenance

� Risk assessment

� Monitoring program

RainHarvest Systems LLC

Rainwater Storage Technologies

Tanks and Cisterns

Treatment Technologies

Recommended treatment techniques for roofwater collection:

� Screen leafs, twigs, and seeds

� Divert or filter smaller suspended particles

www.improvementscatalog.com

www.qtwater.com

www.tanksdirect.com

Leaf Screens

First-flush diverters

Rain filters

Treatment Technologies

Recommended treatment techniques for stormwater collection:

� Screening/settling of trash, debris, and course sediments

� Filtration of nutrients, suspended solids, metals, and VOCs

� Disinfection for viruses and bacteria

Biofiltration Manufactured Media Filters

Imbrium Jellyfish

Ultraviolet

Aqua Azul

Chemical Free

Dolphin WaterCare ™

National/International Guidelines

� WHO – World Health Organization� ARCSA – American Rainwater Catchment

Systems Association� ERCSA – European Rainwater Catchment

Systems Association� Australia – Australia Guidelines for Water

Recycling � Canada Mortgage & Housing Corporation –

Rainwater Harvesting and Greywater Reuse� India – Bangalore Rainwater Club� EPA – Managing Wet Weather with Green

Infrastructure� USGBC – LEED WE Credits� ASLA – Sustainable Sites

State Manuals/Guidelines

� Texas

� Hawaii

� Pacific Areas

� Washington

� Oregon

� Montana

� Virginia

� Georgia

� Ohio

Cities and Counties

� Austin

� Tucson

� Portland

� Santa Fe

� Albuquerque

� San Francisco

National/International Codes

� IGCC – International Green Construction Code, Chapter 7 Rainwater Collection and Distribution Systems Allows ANSI/ASHRAE/USGBC IES Standard 189.1 as an option

� IAPMO – International Association of Plumbing Mechanical Officials, 2010 Green Plumbing & Mechanical Code Supplement covers all aspects of a potable and non-potable rainwater catchment system and is recommended to be used with all codes.

� ASHRAE /USGBC/ASPE/AWWA Standard 191 –Standards for the efficient use of water in building, site and mechanical systems. Covers all uses of water within a site and a building.

National/International Codes

� CSI – Construction Specification InstituteRainwater Harvesting Systems and Components, Gutters and Downspouts, Domestic water Filtration

� ARCSA & ASPE – American Rainwater Catchment Systems Association and American Society of Plumbing EngineersStandards for designers on all components of a rainwater harvesting system.

� NSF International Protocol P151 – Health effects from rainwater catchment system components.Additional standards from NSF and ANSI include ANSI Standard 14, 42, 53, 55, 60, and 61.

LEED V3

LEED V3

Rainwater Harvesting / Stormwater Management

Relevant Prerequisites and Credits

LEED V3

Rainwater Harvesting / Stormwater Management

Relevant Prerequisites and Credits

LEED V3

Rainwater Harvesting / Stormwater Management

Relevant Prerequisites and Credits

Sustainable Sites Initiative (SITES)

Case Study

Yale UniversityRainwater Harvesting at

Kroon Hall

Kroon Hall

Source: OLIN

Source: OLIN

Kroon Hall

Sachem Street

Pro

sp

ect

Str

eet

Kroon Hall

Kroon Hall Kroon Hall

Kroon Hall Case Study

Washington Canal Park, Washington, DC

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Washington Canal Park Washington Canal Park

Contact Information

Skip Graffam, RLA, LEED AP, ASLAPartner/Director of ResearchOLINSGraffam@theolinstudio.comhttp://www.theolinstudio.com/

Nicole Holmes, PE, LEED AP BD+CProject ManagerNitsch Engineeringnholmes@nitscheng.comwww.nitscheng.com

Heather Kinkade, RLA, LEED APAuthor of Design for WaterForgotten Rain, LLChkinkade@forgottenrain.comhttp://www.forgottenrain.com/

RESOURCES

NATIONAL/INTERNATIONAL GUIDELINES

WHO – World Health Organization

ARCSA – American Rainwater Catchment Systems Association

ERCSA – European Rainwater Catchment Systems Association

Australia – Guidance on use of Rainwater Tanks

Australia – Australia Guidelines for Water Recycling: Managing Health and Environmental Risk (Phase 2):

Stormwater Harvesting and Reuse

Canada Mortgage & Housing Corporation – Rainwater Harvesting and Greywater Reuse

India – Bangalore Rainwater Club

EPA – Managing Wet Weather with Green Infrastructure

USGBC – LEED WE Credits

ASLA – Sustainable Sites

STATE MANUALS/GUIDELINES

Texas

Hawaii

Pacific Areas

Washington

Oregon

Montana

Virginia

Georgia

Ohio

CITIES AND COUNTIES

Austin

Tucson

Portland

Santa Fe

Albuquerque

San Francisco

NATIONAL/INTERNATIONAL CODES

IGCC – International Green Construction Code

• Chapter 7 Rainwater Collection and Distribution Systems

• Allows ANSI/ASHRAE/USGBC IES Standard 189.1 as an option

IAPMO – International Association of Plumbing Mechanical Officials

• 2010 Green Plumbing & Mechanical Code Supplement covers all aspects of a potable and

non-potable rainwater catchment system and is recommended to be used with all codes.

ASHRAE /USGBC/ASPE/AWWA Standard 191 – Standards for the efficient use of water in building, site

and mechanical systems.

• Covers all uses of water within a site and a building.

CSI – Construction Specification Institute

• Rainwater Harvesting Systems and Components, Gutters and Downspouts, Domestic water

Filtration

ARCSA & ASPE – American Rainwater Catchment Systems Association and American Society of Plumbing

Engineers

• Standards for designers on all components of a rainwater harvesting system.

NSF International Protocol P151 – Health effects from rainwater catchment system components.

• Additional standards from NSF and ANSI include ANSI Standard 14, 42, 53, 55, 60, and 61.

More Detail:

Legislation around the U.S.:

Tucson, Arizona: In October of 2008, the city of Tucson, Arizona became the first municipality in the

country to require developers of commercial properties to harvest rainwater for landscaping. The new

measure – approved by a unanimous vote by the City Council – requires that new developments meet

50% of their landscaping water requirements by capturing rainwater. The new rule goes into effect June

1, 2010.

Santa Fe County, New Mexico: Residences with 2,500 sq ft or more area must install an active rainwater

catchment system comprised of cisterns. All commercial developments are required to collect all roof

drainage into cisterns to be reused for landscape irrigation.

Albuquerque and Bernalillo County, New Mexico: Residences with 2,500 sq ft or more area must install

an active rainwater catchment system comprised of cisterns. All commercial developments are required

to collect all roof drainage into cisterns to be reused for landscape irrigation.

Legislation around the U.S. (cont.):

State of Texas: In 2001, the Texas legislature amended the Texas Tax Code to allow taxing units of

government the option to exempt from taxation all or a part of the assessed value of the property on

which water conservation modifications have been made.

City of Austin, Texas: The residents of the city of Austin can buy rain barrels at subsidized rates and also

they can claim a rebate for the installation of approved cistern systems. Commercial/industrial

properties can collect rebates up to $40,000 for the installation of rainwater harvesting and Grey water

systems.

City of Portland: Code requires rainwater harvesting permit for projects proposing a minimum storage

size of 1,500 gallons and rainwater used for interior or combined interior and exterior uses.

City of San Antonio, Texas: The San Antonio Water System’s (SAWS) will give up to 50% rebate on the

cost of new water-saving equipment, including rainwater harvesting systems, to its commercial,

industrial and institutional customers. Rebates are calculated by multiplying acre-feet of water

conserved by a set value of $200/acre-foot.

City of San Francisco: Requires a building and plumbing permit for rainwater harvesting system, also

seismic requirements.

State of Arizona: The Government announced a one-time tax credit of 25% of the cost of water

conservation system (the maximum limit is $1,000) for its residents. The water conservation system is

defined as any system, which can harvest residential grey water and/or rainwater. The builders are

eligible to get the tax credit up to $200 per residence unit constructed with a water conservation

system. Any citizen in this state who has purchased a water harvesting system on or after January 1st,

2008, can apply for the Arizona tax credit. There is roughly $250,000 per year allocated for these tax

credits.

Legislation around the world:

Mumbai, India: The state government has made rainwater harvesting mandatory for all buildings that

are being constructed on plots that are more than 1,000 sq m in size.

New Delhi, India: Since June 2001, the Ministry of Urban affairs and Poverty Alleviation has made

rainwater harvesting mandatory in all new buildings with a roof area of more than 100 sq m and in all

plots with an area of more than 1000 sq m, that are being developed. Furthermore, the Central Ground

Water Authority (CGWA) has made rainwater harvesting mandatory in all institutions and residential

colonies in notified areas (South and southwest Delhi and adjoining areas like Faridabad, Gurgaon and

Ghaziabad). This is also applicable to all the buildings in notified areas that have tubewells.

Haryana, India: Haryana Urban Development Authority (HUDA) has made rainwater harvesting

mandatory in all new buildings irrespective of roof area.

Legislation around the world (cont.):

Himachal Pradesh, India: All commercial and institutional buildings, tourist and industrial complexes,

hotels etc, existing or coming up and having a plinth area of more than 1,000 square meters will have

rain water storage facilities commensurate with the size of roof area. No objection certificates, required

under different statutes, will not be issued to the owners of the buildings-unless they produce

satisfactory proof of compliance of the new law. Toilet flush systems will have to be connected with the

rainwater storage tank. It has been recommended that the buildings will have rain water storage facility

commensurate with the size of roof in the open and set back area of the plot at the rate of 0.24 cft. Per

sq m of the roof area.

Bangalore, India: In order to conserve water and ensure ground water recharge, the Karnataka

government in February 2009 announced that buildings, constructed in the city will have to compulsorily

adopt rain water harvesting facility. Residential sites, which exceed an area of 2400 sq ft (40 x 60 ft),

shall create rain harvesting facility according to the new law.

Victoria, Australia: Since July 2005, new houses and apartments in Victoria must be built to meet the

energy efficiency and water management requirements of the 5 Star standard, which requires either a

rainwater tank for toilet flushing, or a solar hot water system.

South Australia: New homes are required to have a rainwater tank plumbed into the house.

Syndey and New South Wales, Australia: The BASIX (Building And Sustainability Index) building

regulations call for a 40% reduction in mains water usage. In order to meet the BASIX target for water

conservation, a typical single dwelling design must include a rainwater tank or alternative water supply

for outdoor water use and toilet flushing and/or laundry, among other water conservation devices.

Gold Coast, Australia: Construction of 3,000-litre (800-gallon) rainwater tank is mandatory in the

Pimpama Coomera Master Plan area of Gold Coast. This is for all homes and businesses centers

connected to the Class A+ recycled Water system (those approved for development after 29 August

2005). The tank should be plumbed to their cold-water washing machine and outdoors faucets.

Queens land, Australia: Residents can get a rebate of up to $1,500 for the purchase and installation of

home rainwater storages.

Germany: Rain taxes in Germany are a great example of internalizing externalities for a more fair

system. Fees are collected for the amount of impervious surface cover on a property that generates

runoff directed to the local storm sewer. That means that the more the rainwater is caught and

conserved, the less rainwater runs off and is added to the storm drains. Less runoff allows for smaller

storm sewers, which, in turn, saves construction and maintenance costs at the site. Thus there is a large

incentive to convert impervious pavement/roof into a porous surface.