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Semelhante a 21 Design Work Shop 7.30.2009 (20)
21 Design Work Shop 7.30.2009
- 1. High Performance
Building Science
Workshop:
Village of Civano
Presented by
Presented by
C. Alan Nichols, P.E., CEM, GBE, LEED AP
C. Alan Nichols, P.E., CEM, GBE, LEED AP
Jason Laros, LEED AP
Jason Laros, LEED AP
Justin Cupp
Justin Cupp
Design Tools for the
21st Century
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
CIVANO, located in Tucson, Arizona, was originally conceived as
the "Solar Village" as an outgrowth of builder and consumer
interest in solar designs with a natural, and appropriate extension
of desert living. Led by the Metropolitan Energy Commission, a
number of local builders and environmentalists obtained a
commitment from the Arizona Energy Office to fund the planning
and design of the prototype community. As research progressed,
the planners soon began to contemplate comprehensive
extensions of their original idea including energy and water
conservation, solid waste reduction, and lower air pollution.
"Solar Village" soon became a much larger concept, and the
Community of CIVANO began to take shape. It was to be more
sustainable, and it was to incorporate many of the compact, life-
enhancing and socially integrated aspects of American's small
towns.
1
- 2. SESSION ONE
WATER CONSERVATION
By:
Justin Cupp
Owner
Home Improvement & Maintenance, Inc.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
2
- 3. Conservation Of Water
Low Water Use Landscape
Required
Drastically Reduce Potable
Water Used for Irrigation
Reclaimed Water
• Optional at home,
required in common
areas
Rain Water Cisterns
• Common retrofit in
Phase I
Grey Water Systems
• Few have attempted
grey water systems
On Site Retention
• Used in Phase II at
the home level and
common areas
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Civano neighborhoods have performed well in
the area of water conservation.
Desert landscaping, reclaimed water in
neighborhood I, and several rainwater
collection systems are used to achieve this
success.
3
- 4. Landscape And Irrigation
Requirements
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
5.0 LANDSCAPE AND IRRIGATION REQUIREMENTS
5.1 LANDSCAPE REQUIREMENTS
5.1.1 Soil pretreatment. Due to construction site compaction, the soils in planting areas must be pretreated to
ensure adequate infiltration of harvested water. Soil Pretreatment techniques, locations and schematics
should be provided in the Implementation Plan.
5.1.2 Plant selection and placement. Plants selected for use within descreet WHIAs shall have compatible water
needs. Plants shall be positioned to account for the level of expected inundation. They may be placed on the
bottoms or sides of recessed areas or the tops of adjacent soil where their roots can grow toward adjacent moist
soil. Other placement considerations shall include sun exposure, maintenance requirements, shape, form and
aesthetics
5.1.3 Mulch placement. Mulch shall be positioned away from the base of plant trunks to avoid excessive moisture
there.
5.2 IRRIGATION REQUIREMENTS
5.2.1 Irrigation systems shall be fitted with irrigation controllers and shall be capable of monitoring and
responding to plant water needs through the use of soil moisture gauges, tensiometers, weather stations
and/or evapotranspiration data. The irrigation technology chosen should be capable of preventing the irrigation
system from running if sufficient soil moisture is present to support the vegetation. All systems shall include rain
shut off devices. Instruments shall be correctly placed to ensure plants are kept healthy using a combination of
harvested and non-harvested water and to ensure the stated water-saving goal of the Ordinance is met.
5.2.2 Irrigation timers shall not be used for primary irrigation system control except in the following situations:
3-year plant establishment period, and facilities with container systems that are inter- plumbed
with other water supplies to provide direct irrigation of landscape plants.
5.2.3 Irrigation plans must include calculations for estimated water use based on assumptions about plant water
demand and canopy size used in the Site Water Budget.
5.2.4 Drip irrigation systems shall meet and maintain a minimum 80% emission uniformity.
4
- 5. Creating a Water Budget to Live
By
Plant water needs
Water Storage
Summary
Landscape
Collection Area
Pavement
Collection Area
Water Supply
Estimate (Rooftop
“footprint”)
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
4.2 WATER HARVESTING IMPLEMENTATION PLAN
The Water Harvesting Implementation Plan (Implementation Plan) shall consist of a separate sheet with a plan view layout of the site. The format and design of the Implementation Plan shall be consistent with the base plan, be it a Plat (DS
2-03), Site Plan (DS 2-04), Development Plan (DS 2-05), or their successor documents, as applicable. The Implementation Plan shall include all details necessary and appropriate to convey the technical concept of the water
harvesting system design and to facilitate proper installation and maintenance of the water harvesting system in compliance with the Ordinance and this standard.
Submittal of the Implementation Plan for water harvesting shall be made concurrently with the Development Plan and Landscape Plan. Revision of the Implementation Plan may be required in conjunction with preparation of the Grading
Plan in order to coordinate the construction details and specifications.
4.2.1 The following general information shall be provided on the Implementation Plan:
A. The case number shall be located in the lower right corner of the plan.
B. The means by which monthly rainfall data will be obtained and recorded
C. The means by which monthly irrigation data will be obtained and recorded
D. Soil pretreatment techniques, locations and schematics
E. Maintenance notes
F. Monitoring and Annual Reporting Requirements
4.2.2 Tabulated Data
The Implementation Plan shall include a table detailing information for each identified Water Harvesting Infiltration Area (WHIA) at the site, and for the site as a whole, as described below.
A. General information: 1. WHIA identifier
2. Spatial size (square feet) of WHIA
3. Average depth (feet) of WHIA
4. Capacity (gallons) of WHIA
5. Type and general location where sensors that control the irrigation system will be placed
B. Plant canopy information 1. Plant canopy area (square feet) that is served by each WHIA, consisting of the sum of understory, midstory and
overstory plant canopies at 60 percent of the mature plant size
2. Plant water demand category
3. Total annual plant water demand (gallons)
C. Information about passive and/or active water harvesting systems serving the Water Harvesting Infiltration Area:
1. For the Subwatershed passively serving each WHIA:
a. Subwatershed identifier
b. Spatial size (square feet) of the subwatershed
c. Material the subwatershed is made of
d. Percent of plant water demand provided by this subwatershed to the WHIA
2. For the containment system actively serving each WHIA:
a. Tank Identifier
b. Tank capacity (gallons)
c. Tank location
d. Percent of plant water demand provided by this tank to the WHIA
D. Any additional information needed to document how 50% of irrigation demand will be met using harvested water.
E. Data tabulated for the entire site:
1. Percent of annual landscape water demand met using harvested water
2. Water harvesting capacity that will offset standard retention/detention basin size.
F. Additional plan information may be requested or required by the Development Services Department (DSD)
Director to evaluate rainwater-harvesting proposals.
4.2.3Mapped Data The Implementation Plan shall graphically show the following, drawing on tabulated data:
A. For the area receiving infiltrated water, the WHIA:
1.Indicate the boundary of each WHIA and show its identifier
2. Use arrows to show water flow directions within WHIA, including flow direction at inlets and outlets
3. Show location where sensors that control the irrigation system will be placed
B. Plant Canopy information: Indicate the boundary of the plant canopy area to be served by each WHIA
C. Information about Passive and/or Active Water Harvesting Systems serving each WHIA:
1. Passively supplied water:
a. Indicate the Subwatershed Area and show its identifier
b. Use arrows to indicate the flow path water will take from source to WHIA
c. Indicate spot elevations for the bottoms of water harvesting structures, at spillways, and to define other grades as needed
d. Indicate the location of all surface or subsurface infiltration structures, pipelines, spillways, French drains, scuppers, curb cuts and other
infrastructure elements needed to convey, store or overflow passively supplied water, or to control erosion
2. Actively supplied water
a. Show tank and show its identifier
b. Label tank as delivering water by gravity flow or pump
c. Use arrows to indicate flow path water will take from source to WHIA
d. Show additional piping, pump and other infrastructure needed to store, overflow, and convey water to WHIA
4.2.4 Additional Information
Additional notes shall be provided on the Implementation Plan to ensure current and subsequent site owners and operators are informed of the inspection and maintenance required in Section 6 of this development standard.
5
- 6. Soil Pretreatment
Due to
construction site
compaction, the
soils in planting
areas must be
pretreated to
ensure adequate
infiltration of
harvested water.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
6
- 7. Plant Selection And Placement
Plants selected for
use within discreet
WHIA’s shall have
compatible water
needs. Plants shall
be positioned to
account for the level
of expected
inundation.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Water Harvesting Infiltration Areas. Pervious areas of a site where harvested water
collects and soaks into the subsurface to support landscape plants. Water Harvesting
Infiltration Areas include exposed soil shaped to hold and infiltrate water,
permeable soil subgrades overlain with impervious pavement that receive water via
perforated pipes or other conveyance techniques, structured soil overlain with
permeable paving, and other strategies that collect water and allow it to soak into
the subsurface to support landscape plants.
7
- 8. Irrigation Systems
Irrigation systems shall be
fitted with irrigation
controllers and shall be
capable of monitoring and
responding to plant water
needs through the use of
soil moisture gauges,
tensiometers, weather
tensiometers,
stations and/or
evapotranspiration data.
Drip irrigation systems shall
meet and maintain a
minimum 80% emission
uniformity
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
8
- 9. Large Scale Fully Integrated
Into Commercial Irrigation
System
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
CORPORATE INCOME TAX CREDIT
1. The credit is for costs incurred of installing a water conservation system plumbing stub out that collects all graywater sources that end at a
plumbing stub out that is separate and distinct from the regular plumbing system. These costs are for installing or including such a system in
one or more houses or dwelling units located in Arizona and constructed by the taxpayer,
2. This credit is effective for taxable years from and after December 31, 2006. It ends before January 1, 2012. Therefore, the credit is
available for tax years 2007, 2008, 2009, 2010 and 2011.
3. To qualify for the credit, the stub out must:
a. Comply with rules adopted by the Arizona Department of Environmental Quality and that relate to the direct reuse of reclaimed water.
b. Meet applicable local building codes.
4. The credit cannot exceed $200 for each separate house or dwelling unit.
5. If the credit exceeds the tax due on the taxpayer’s tax return, it can be carried forward for five years.
6. Co-owner of a business, including corporate partners in a partnership, may each claim only the pro rata share of the credit, based on
ownership interest.
7. The corporation must make application to the Arizona Department of Revenue (ADOR) on the appropriate ADOR form and must obtain a
Credit Certification indicating that the taxpayer is entitled to take this credit and the amount of credit to which the taxpayer is entitled.
Application can only be made after actual purchase and installation of the system. . Copies of documentation for installation of the plumbing
stub outs, with date of installation and addresses shown, must be attached to the application.
8. If the taxpayer’s installation of the stub outs is contingent upon receiving the credit, the taxpayer can contact Rosemary Soto at (602) 716-
6595 to see how much room under the credit limitation is available. Although a guarantee of credit availability cannot be provided, a fairly
educated guess of credit availability can be made.
9. The Credit Certification should be attached to the taxpayer’s corporate income tax return at the time of filing as proof of eligibility.
10. The maximum amount of corporate income tax credits the ADOR can certify in a calendar year is $500,000.
11. Credits shall be granted on a first come, first served basis.
12. If an application is received that, if authorized, would require the ADOR to exceed $500,000, ADOR shall grant that applicant only the
remaining credit amount that would not exceed the $500,000 limit.
13. ADOR may verify that a water conservation system has been installed by the taxpayer.
If you have questions regarding this credit, contact Rosemary Soto at (602) 716-6595. Mail completed applications to:
Rosemary Soto, Economic Specialist
Office of Economic Research and Analysis
Arizona Department of Revenue
P.O. Box 25248
Phoenix, AZ 85002
9
- 10. Civano Water Use
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Civano I uses more water than Civano II, but
less potable water due to the active use of
reclaimed water in many of the residences.
Reclaimed water is not being sent to Phase II
residences because it is not practical given the
costs. However, small, desert landscaped yards
in Phase II are probably the driving force
behind the overall water savings realized there.
10
- 11. Civano Phase I vs. Phase II
Civano I vs Civano II Water Use
12
10
8
ccf per Mo
6
4
2
0
Apr- May- Jun- Jul- Aug- Sep- Oct- Nov- Dec- Jan- Feb- Mar-
06 06 06 06 06 06 06 06 06 07 07 07
Civano II Total W ater Use Civano I Total
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
11
- 12. Civano I & II vs. City
Civano I, Civano II, City
16
14
12
ccf per Mo
10
8
6
4
2
0
Apr- May- Jun- Jul- Aug- Sep- Oct- Nov- Dec- Jan- Feb- Mar-
06 06 06 06 06 06 06 06 06 07 07 07
City Potable Water Use Civano I Potable Civano II Total
Civano I Reclaimed Civano I Total
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Civano I uses more water than Civano II, but
less potable water due to the active use of
reclaimed water in many of the residences.
Reclaimed water is not being sent to Phase II
residences because it is not practical given the
costs. However, small, desert landscaped yards
in Phase II are probably the driving force
behind the overall water savings realized there.
12
- 13. Total Water Savings
2006-2007 Civano I Civano II City
12 Month Potable Use (ccf)
(ccf) 54.8 75.6 131.1
12 Month Reclaimed Use (ccf)
(ccf) 31.4 0 0
Total 86.2 75.6 131.1
Reduction Over City Average Use, Potable 58% 42%
Baseline
Reduction Over City Average Use, Total 34% 42%
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Here are the percentages. Again, notice Civano
I uses less potable water than Civano II, but
more water overall.
13
- 14. COMMERCIAL RAINWATER
HARVESTING and
RESIDENTIAL GREY WATER
STUBOUTS –
TUCSON’S DEVELOPMENT
STANDARD
Tucson’s Water
Challenge
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
. INTRODUCTION
Harvesting rainwater is a useful strategy for providing supplemental irrigation water to
commercial landscapes, making more efficient use of the desert’s most limited
resource: water. The City of Tucson Mayor and Council adopted the Commercial
Rainwater Harvesting Ordinance October 14, 2008 to increase the use of harvested
rainwater at commercial sites in Tucson and to decrease use of potable and
reclaimed water supplies. The ordinance takes effect June 1, 2010.
PURPOSE
This Development Standard has been prepared to facilitate effective use of available
rainwater resources for landscape irrigation in commercial development as a
means of reducing dependency on potable and reclaimed water sources. It clarifies
requirements for compliance with Ordinance No. 10597, the Commercial
Rainwater Harvesting Ordinance (Ordinance), including the key requirement of
meeting 50% of landscape water demand using harvested water. This standard
provides:
Design considerations and technical requirements for passive and active water harvesting
systems;
Requirements and guidelines for the preparation and implementation of Rainwater
Harvesting Plans;
Requirements for landscape and irrigation at water harvesting sites
Recommended maintenance steps
Elements required for compliance with the Ordinance
Enforcement provisions
Resources to assist applicants in the selection, design and operation of water harvesting
strategies
14
- 15. Commercial Rainwater
Harvesting Ordinance
By June of 2010
all commercial sites
will be required
to supplement 50% of
landscape water
demand
by collecting rainwater
on site.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
15
- 16. City Adopts New Development
Standard
INTRODUCTION. By minimizing amenity
irrigation demands, rainwater harvesting
reduces demand on the desert's most limited
resource: water.
PURPOSE. The Development Standard has
been prepared to facilitate effective use of
available rainwater resources for landscape
irrigation in commercial development as a
means of reducing dependency on potable
and reclaimed water sources. It shall clarify
requirements for compliance with Ordinance
No. 10597, the Commercial Rainwater
Harvesting Ordinance.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
1.1 INTRODUCTION
Harvesting rainwater is a useful strategy for providing supplemental irrigation water to commercial landscapes, making
more efficient use of the desert’s most limited resource: water. The City of Tucson Mayor and Council adopted the
Commercial Rainwater Harvesting Ordinance October 14, 2008 to increase the use of harvested rainwater at
commercial sites in Tucson and to decrease use of potable and reclaimed water supplies. The ordinance takes
effect June 1, 2010.
1.2 This Development Standard has been prepared to facilitate effective use of available rainwater resources for
landscape irrigation in commercial development as a means of reducing dependency on potable and reclaimed
water sources. It clarifies requirements for compliance with Ordinance No. 10597, the Commercial Rainwater
Harvesting Ordinance (Ordinance), including the key requirement of meeting 50% of landscape water demand
using harvested water. This standard provides:
A. Design considerations and technical requirements for passive and active water harvesting systems;
B. Requirements and guidelines for the preparation and implementation of Rainwater Harvesting Plans;
C. Requirements for landscape and irrigation at water harvesting sites
D. Recommended maintenance steps
E. Elements required for compliance with the Ordinance
F. Enforcement provisions
G. Resources to assist applicants in the selection, design and operation of water harvesting strategies
APPLICABILITY
This standard applies to all commercial development plans submitted after June 1, 2010.
16
- 17. Smart Harvesting
Harvesting
rainwater depends
on need
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
DEFINITIONS
Other than as provided below, definitions used in this Standard are found in the Development Standards Glossary or Sec. 6.2.0 of the Land Use
Code (LUC).
Active Water Harvesting. The collection of stormwater runoff into containment systems for storage and later diversion to beneficial uses.
Catchment Areas. Areas of a site where water is harvested, including where rain falls directly on plant canopies and pervious Water Harvesting
Infiltration Areas, and where rain falls on impervious rooftops, sidewalks, parking lots, driveways and other surfaces from which stormwater
runoff is directed toward Water Harvesting Infiltration Areas.
Catchment Ratio. The ratio of the water harvesting catchment area to the canopy area of the plants that use water harvested from that catchment
area.
Commercial development. Any new non-residential development that is intended to be used primarily for commercial activities and is subject to
applicable City Codes.
Containment systems. Above-ground tanks, below-ground tanks, other types of above- and below-ground water-holding containers, and associated
pipes and transmission equipment that enable beneficial use of the harvested water.
Evapotranspiration (ET). The transfer of water from land surface to the atmosphere through the combination of evaporation and plant
transpiration.
Impervious Subwatersheds. Discrete nonporous subareas of a site--including rooftops, sidewalks, parking lots, driveways and other impervious
areas--that capture stormwater runoff and deliver it through gravity flow to discrete containment systems or Water Harvesting Infiltration Areas.
Passive Water Harvesting. The collection of stormwater runoff directly into Water Harvesting Infiltration Areas without the temporary storage of
water in a containment system.
Plant Canopy Area. The square feet of ground covered by plants and trees as viewed from above for a given area, consisting of the sum of
understory, midstory and overstory plant canopies at 60 percent of their mature plant size.
Rainwater. Liquid precipitation falling from the sky before it lands on a surface.
Stormwater. Rainwater that has landed on a surface becomes stormwater.
Water harvesting. The process of intercepting stormwater and putting it to beneficial use.
Water Harvesting Infiltration Areas. Pervious areas of a site where harvested water collects and soaks into the subsurface to support landscape
plants. Water Harvesting Infiltration Areas include exposed soil shaped to hold and infiltrate water, permeable soil subgrades overlain with
impervious pavement that receive water via perforated pipes or other conveyance techniques, structured soil overlain with permeable paving, and
other strategies that collect water and allow it to soak into the subsurface to support landscape plants.
Smart harvesting includes an ability to have a balance of high demand and low demand plants to create the appearance of a lush
landscape, but drought tolerant. Canopy landscaping is key to reduce the heat island effect and overall water demand.
17
- 18. Rainwater Harvesting
Techniques
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
3.0 DESIGN CONSIDERATIONS AND TECHNICAL REQUIREMENTS
Two primary strategies for harvesting water are commonly used in the southwest US to support
landscape water needs. Passive water harvesting is accomplished by infiltrating rainfall and
stormwater runoff directly in Water Harvesting Infiltration Areas. Active water harvesting stores
harvested water in containment systems located above or below ground so the stored water is
available for later beneficial use. The commercial facility may determine the strategy or strategies
most appropriate for their site.
18
- 19. Two Primary Strategies
Passive Rainwater
Harvesting
Active Rainwater
Harvesting
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
19
- 20. Passive Water Harvesting
Passive Rainwater
Harvesting is the
intentional
contouring of
landscape to utilize
the water shed off of
a surface without
the use of a
containment system
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Passive Water Harvesting. The collection of stormwater runoff directly into Water Harvesting Infiltration Areas without the
temporary storage of water in a containment system.
3.1.1 Passive Water Harvesting Design Considerations
An array of techniques and designs are available to accomplish passive water harvesting. Whatever techniques or designs are
used, the items listed below should be considered to create safe, efficient and effective passive water harvesting systems.
A. Use Water Harvesting Infiltration Areas, where feasible, to offset the size of a retention/detention
basin that may be needed at a site. Consult Appendix C of the City
of Tucson Water Harvesting Guidance Manual for information
on the allowed offset.
B. The area and depth of Water Harvesting Infiltration Areas should be determined according to the
anticipated volume of harvested water that will enter these areas and
the infiltration characteristics of the underlying soil.
C. The edge of Water Harvesting Infiltration Areas should be set back from building foundations or
other structures to allow for positive drainage of water. Consult a soils professional where
necessary.
D. Planting areas that harvest water should be recessed below the grade of adjacent hardscapes.
Hardscape surfaces should be sloped toward adjacent recessed
planting areas.
E. Pedestrian circulation should be designed to discourage cutting across recessed planting areas to
avoid soil compaction, erosion, and damage to plants.
F. Maximum reveal at the edge of public sidewalks and pedestrian circulation paths should be 1 to 2
inches to minimize the risk of injury to pedestrians. A minimum
12-inch wide shoulder with a maximum two (2) percent cross slope
away from a public sidewalk or pedestrian circulation path should be provided where possible.
G. Water Harvesting Infiltration Areas should be stabilized for dust control purposes. Techniques could
include spreading ½-inch or larger rock, hydroseeding with
native seed mixes, other using other stabilizing techniques and materials. Fine-grained
particles that could block water infiltration by clogging soil pores should be washed
from materials prior to placement. Avoid the use of fine-grade decomposed granite within or directly
adjacent to Water Harvesting Infiltration Areas due to the potential for shed silts and clays
to block water infiltration.
H. Soils within Water Harvesting Infiltration Areas should be modified as needed to counteract the
effects of mechanical compaction and/or poor soil conditions to
ensure appropriate water infiltration.
I. Organic mulch is appropriate for reducing evaporation and increasing soil quality in Water Harvesting
Infiltration Areas in those locations where the vegetation, water collection, erosion
conditions, and slope characteristics are amenable to its use.
20
- 21. Curb Cuts and Gabions
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
3.1.2 Passive Water Harvesting Technical Requirements
The following technical requirements apply to all passive water harvesting systems.
A. Water Harvesting Infiltration Areas shall be designed so that
water infiltrates into soil within twenty (24) hours.
B. Water Harvesting Infiltration Areas shall be designed to minimize
ponding in areas that may create a nuisance for
pedestrians. Ponding is not allowed on or over public sidewalks or pedestrian
circulation paths.
C. Materials for erosion protection shall be specified, where
necessary due to erosion potential. The ground
surface treatment of spillways and other areas that convey water
flows shall be able to withstand scouring.
D. Plants with similar water demands shall be placed in the same
areas within Water Harvesting Infiltration Areas.
21
- 22. Berms and Swales
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
1. Passively supplied water:
a. Indicate the Subwatershed Area and show its identifier
b. Use arrows to indicate the flow path water will take from
source to WHIA
c. Indicate spot elevations for the bottoms of water
harvesting structures, at spillways, and to define other
grades as needed
d. Indicate the location of all surface or subsurface
infiltration structures, pipelines, spillways, French drains,
scuppers, curb cuts and other infrastructure elements
needed to convey, store or overflow passively supplied
water, or to control erosion
22
- 23. Active Water Harvesting
Active water
harvesting is the use of
containment systems
located above or below
ground, such that the
stored water is
available for later,
beneficial, use.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
3.2.1 Active Water Harvesting Design Considerations
An array of techniques and designs are available to accomplish active water harvesting. Whatever
techniques or designs are used, the items listed below should be considered to create safe,
efficient and effective active water harvesting systems.
A. Tanks may be constructed of metal, plastic, masonry, reinforced concrete,
fiberglass, or other suitable DSD-
approved material designed to store water.
B. Above-ground tank construction material or coating should be opaque to
prevent sunlight from inducing algae growth.
Any portion of a subsurface tank that is exposed to sunlight should be opaque to prevent sunlight
from inducing algae growth.
C. A “first flush device” is intended to prevent the dust, grit, leaves and other
materials that may accumulate on a roof from being washed
into a water harvesting tank. This is accomplished by deflecting the first flush of
stormwater runoff from entering the tank inlet line. The
installation of first flush devices is strongly
recommended but not required.
D. The dimensions of tanks may be determined by the applicant based on site-
specific design needs.
E. Inlet piping may convey water overhead from a roof to a tank, or in a U-shaped
configuration that conveys water to a lower entry point on
the tank. The U-shaped configuration should be designed to hold standing water, and
must be pressure rated and sealed to prevent leaks.
F. Designs that involve water falling freely through the air before entering a tank
may be allowed provided the design minimizes the entry
of light and mosquitoes into the tank.
23
- 24. Design Schematics
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
3.2.2 Active Water Harvesting Technical Requirements
The following technical requirements apply to all active water harvesting systems.
A. Materials must be installed per manufacturer’s specifications.
B. Consult the International Building Code for applicable regulations.
C. Containment system plumbing is per the International Plumbing code.
D. Tanks and covers shall be constructed of materials appropriate for use for storing water.
E. Above-ground tank construction material must be able to endure UV exposure without loss of structural
integrity, or must be UV protected with an appropriate coating. Any portion of a subsurface tank that is
exposed to sunlight must be able to endure UV exposure without loss of structural integrity, or must be UV protected with an appropriate coating.
F. Tanks shall have a base or foundation that meets manufacturer’s specifications. If no specifications are
provided by the manufacturer, the base shall be designed by an engineer.
G. Sub-surface storage tanks shall be constructed of materials designed for holding water underground. Below-
ground tanks must be designed and installed under the guidance of a civil or structural engineer and/or tanks must be installed per manufacturer’s
specifications regarding bedding, setting the tank, strapping or other anchoring device, load bearing characteristics and backfill requirements.
H. There must be a structured overflow device installed with the tank to automatically allow excess infill water to
exit the tank safely.
I. Outlets for overflow pipes shall be positioned so as not to compromise the foundations of buildings or other
structures.
J. If debris screening is used for inlets to tanks, screening must be configured in such a way that an unmaintained
screen cannot block inlet pipes to a tank. Obstructed screens can prevent water harvesting and back water up on the roof creating unsafe weight load
conditions on the roof.
K. An overflow mechanism, separate from that provided inside the tank, shall be provided to ensure that water
cannot back up on a roof. Roof overflow drains shall not be connected to tanks.
L. Tanks must have an inspection port of sufficient size to conduct any necessary visual inspection, maintenance,
cleaning, repair or other tasks as described in the manufacturer’s specifications.
M. If a manhole is provided with the intent of allowing human access into a tank, it must meet any applicable size
and safety requirements.
N. Containment systems shall be designed, maintained and operated to prevent mosquito harboring and/or
breeding.
O. Locations of containment systems shall be in accordance with applicable codes.
P. A reverse-pressure backflow-preventer assembly is required when connecting irrigation from an active water
harvesting system to a potable water irrigation system to protect the public water system and/or building water
system.
Q. Systems that include an outlet to allow authorized people to tap water from the active water harvesting system
directly shall include a keyed hose bib and be posted with a yellow placard with black text stating the water is
non-potable, as required by Section 601.2.2 of the Uniform Plumbing Code.
2. Actively supplied water
a. Show tank and show its identifier
b. Label tank as delivering water by gravity flow or pump
c. Use arrows to indicate flow path water will take from source to WHIA
d. Show additional piping, pump and other infrastructure needed to store, overflow, and convey water
to WHIA 24
- 25. Foundation Prep
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
F. Tanks shall have a base or foundation that meets manufacturer’s specifications. If no specifications are provided by the
manufacturer, the base shall be designed by an engineer.
Galvanized culverts were not designed to hold water, only to let water pass through. It just so happens that they conveniently do
hold water and at a cost effective price. Therefore, there are no specifications from the manufacturer and an engineer will
have to be involved.
Installer’s tip: Once pipe and rebar are put in place concrete should be poured to stabilize assemblies while setting the culverts in
place. There are two options for pouring. First, a whole slab can be poured followed by a second slab which the culverts
would be sitting in. Or the second option would be to spot concrete each assembly, enough to be stable when setting the
culverts upright. The second option allows for a more thorough pour, whereas the first option may not allow the two slabs to
perfectly adhere to one another.
25
- 26. Set In Place
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Before setting culvert in concrete, steps must be taken to
ensure system will not fail upon an initial rainstorm event:
• If a culvert is cut with a torch, it destroys the
galvanization of the steel. Therefore it is important to
coat the unprotected part with any product (tar, epoxy or
polymer paints, etc.) that adheres to metal and is durable
in a wet environment.
• The seam in the culvert will also have to be “painted.”
The manufacturer does not rate galvanized culverts for
the collection of rainwater therefore the seam on a culvert
cannot be guaranteed to be perfectly sealed. Use the same
product used to coat the unprotected steel to seal the
seam.
Now for lifting the culverts into place.
Manpower!...or a crane, whichever you choose, the culvert
just needs to get on the foundation before the concrete
dries.
26
- 27. Overflow
When sizing
overflow pipe
consult with a
mechanical
engineer or refer to
the I.P.C
(International
Plumbing Code)
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
•There must be a structured overflow device installed with the tank to automatically
allow excess infill water to exit the tank safely.
•Outlets for overflow pipes shall be positioned so as not to compromise the
foundations of buildings or other structures.
•An overflow mechanism, separate from that provided inside the tank, shall be
provided to ensure that water cannot back up on a roof. Roof overflow drains shall
not be connected to tanks.
It’s ideal to direct overflows towards retention/detention basins or some other
passive water harvesting application.
27
- 28. Lid
Covers on storage
tanks are necessary
to prevent animals
and debris from
entering and
potentially causing
clogging
Prevents algae
growth inside tank
Discourages
mosquito harboring &
breeding
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Tanks and covers shall be constructed of materials appropriate for use for storing
water.
Tanks must have an inspection port of sufficient size to conduct any necessary
visual inspection, maintenance, cleaning, repair and other tasks as described in the
manufacturer’s specifications.
If a manhole is provided with the intent of allowing human access into a tank, it
must meet any applicable size and safety requirements.
Containment systems shall be designed, maintained and operated to prevent
mosquito harboring and/or breeding.
28
- 29. Connections, Wire Cage, and
Vine
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
P. A reverse-pressure backflow-preventer assembly is required when connecting
irrigation from an active water harvesting system to a potable water irrigation
system to protect the public water system and/or building water system.
Q. Systems that include an outlet to allow authorized people to tap water from the
active water harvesting system directly shall include a keyed hose bib and be posted
with a yellow placard with black text stating the water is non-potable, as required by
Section 601.2.2 of the Uniform Plumbing Code.
Mechanical ball valves are now available at any Lowe’s or Home Depot. They cost
$10. Unlike traditional irrigation valves they open under no water pressure.
However, like traditional irrigation, it allows the user to program it for a regular
watering schedule.
29
- 30. Parking Structure For
Rio Nuevo
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
30
- 31. Distribution Of
Rainwater To Site
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
31
- 32. L.U.C. Code for Containment
Tanks
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
MEMORANDUM
DATE: February 19, 2009
TO: DSD Staff
FROM: Craig L. Gross, Zoning Administrator
SUBJECT: Water Harvesting Cisterns
The following is a clarification of existing Land Use Code regulations regarding the heights and setbacks of water harvesting cisterns.
Cisterns are storage tanks for rainfall collected from a roof or other catchment area. A water harvesting cistern is considered an accessory structure.
Land Use Code Sections 3.2.5 and 3.2.6 detail the requirements for accessory structures. The following standards are to be used for reviewing cisterns
for zoning purposes:
1. A cistern no more than five (5) feet in height and no more than ten (10) square feet in area (approximately 3.5 feet in diameter), may be placed
anywhere within a property boundary with zero (0) setbacks from property lines (LUC 3.2.5.2.F).
2. A cistern over five (5) feet but no more than six (6) feet in height and no more than ten
(10) square feet in area (approximately 3.5 feet in diameter), may be placed anywhere in
the defined side or rear yard (excluding street perimeter yards) with zero (0) setbacks
from property lines (LUC 3.2.5.2.C) if screened by a wall or fence of equivalent height.
3. A cistern over six (6) feet in height or more than ten (10) square feet in area
(approximately 3.5 feet in diameter), may be placed anywhere in the defined side or rear
yard subject to compliance with the perimeter yard width requirements applicable to the
zone. The perimeter yard width requirements may be reduced with the written consent of
the adjoining, or when separated by an alley, the adjacent property owner, or by
completing the Design Development Option (DDO) process (LUC 3.2.5.2.C).
4. A cistern that is part of and integrated into the design of the principal building may be
considered part of the principal building as determined by the Zoning Administrator on a
case by case basis.
5. Maximum height of a cistern in a residential zone is twelve (12) feet (LUC 3.2.5.3.B).
Maximum height of a cistern in a commercial zone is equal to the height limitation of the
principal building (LUC 3.2.5.4.B). All height measurements are from established design
grade at the base of the cistern and includes any foundations or bases required to support
the cistern.
6. Other applicable building codes and fire codes may apply.
32
- 33. Goals for Tucson
The facility may determine
the strategy or strategies
most appropriate for their
site.
Preparation of the Water
Budget and Rainwater
Harvesting Implementation
Plan, by the applicant,
showing appropriate
strategy(s), and illustrate
how the use of the selected
strategy(s) will accomplish
the 50% off set requirement
pursuant to the Ordinance.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
4.0 RAINWATER HARVESTING PLAN
A Rainwater Harvesting Plan shall be submitted with all applications for commercial developments
at which landscaping is required. The Rainwater Harvesting Plan shall consist of two elements: a
Site Water Budget and a Water Harvesting Implementation Plan. Preparation of the Rainwater
Harvesting Plan elements requires coordination between project managers, site engineers and
landscape architects from the inception of the project. The two elements of the Rainwater
Harvesting Plan shall illustrate how water harvesting will meet 50 percent of landscape water
demand, as required by the Ordinance. Resources describing various water-harvesting strategies
are listed in Appendix A to assist—but not limit—applicants as they design water harvesting for
their site.
4.1 SITE WATER BUDGET
The Site Water Budget shall detail landscape water demand and the harvested water supply needed
to meet 50 percent of this demand. The Site Water Budget and the Water Harvesting
Implementation Plan shall be consistent with one another.
A water budget format is shown in Appendix B, along with the background data and assumptions
used to develop it. This water budget format will be available to applicants as an Excel
spreadsheet. Applicants may use this water budget format to enter site specific data and develop
their Site Water Budget. Alternatively, applicants may develop their own Site Water Budget
format. Whichever format is used, the submitted Site Water Budget shall incorporate and
provide the following:
4.1.1 Water Demand
Applicants shall use plant water demand categories and data provided in Appendix B unless an
alternative assumption is provided and satisfactorily justified.
4.1.2 Water supply
Applicants shall use the effective monthly rainfall assumptions shown in Appendix B unless an
alternative assumption is provided and satisfactorily justified.
4.1.3 Output
Output of the Site Water Budget shall include calculations showing how 50 percent of landscape
water demand will be met using harvested rainwater, and shall include assumptions and
supporting calculations as necessary to document these outputs.
33
- 34. Corporate And Individual
Income Tax Credit For Water
Conservation Systems
This credit is for costs associated with
installing a water conservation system in
the taxpayer’s residence located in
taxpayer’
Arizona.
The Tax Credit is 25% or up to $1000, the
lesser of the two.
The tax credit incentive is set to expire in
2011
If the credit exceeds the tax due on the
taxpayer’s tax return, it can be carried
taxpayer’
forward for five years.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
INDIVIDUAL INCOME TAX CREDIT
This credit is for costs associated with installing a water conservation system in the taxpayer’s residence located in Arizona.
A water conservation system is a system or series of components or mechanisms that are designed to provide for the collection of rainwater or residential
graywater. A water conservation system includes a system that is capable of storing rainwater or residential graywater for future use and reusing the
collected water for the same residential property.
1. To qualify for the credit, a residential graywater conservation system and its installation must comply with rules that are adopted by the Arizona
Department of Environmental Quality (ADEQ) and that relate to the recovery and disposal of graywater. For detailed information please contact ADEQ:
• www.azdeq.gov/environ/water/permits/reclaimed.html
• Phone number: (602) 771-2300
Toll free: (800) 234-5677
2. This credit is effective for taxable years from and after December 31, 2006. It ends before January 1, 2012. Therefore, the credit is available for tax years
2007, 2008, 2009, 2010 and 2011.
3. The credit is equal to the lesser of 25% of the cost of the system or $1,000.
4. Only one credit in one tax year is allowed per residence.
5. Tax credits claimed over multiple tax year years by a taxpayer for the same residence cannot exceed $1, 000.
6. If the credit exceeds the tax due on the taxpayer’s tax return, it can be carried forward for five years.
7. The individual must make application to the Arizona Department of Revenue (ADOR) on the appropriate ADOR form and must obtain a Credit
Certification indicating that the taxpayer is entitled to take this credit and the amount of credit to which the taxpayer is entitled. Application can only be
made after actual purchase and installation of the system. Copies of the receipt for purchase and installation of the system, with date of installation shown,
must be attached to the application.
9. If the taxpayer’s purchase and installation of the system is contingent upon receiving the credit, the taxpayer can contact Rosemary Soto at (602) 716-
6595 to see how much room under the credit limitation is available. Although a guarantee of credit availability cannot be provided, a fairly educated guess
of credit availability can be made.
10. The Credit Certification must be attached to the taxpayer’s individual income tax return at the time of filing as proof of eligibility.
11. The maximum amount of individual income tax credits the ADOR can certify in a calendar year is $250,000.
12. Credits shall be granted on a first come, first served basis.
13. If an application is received that, if authorized, would require the ADOR to exceed $250,000, ADOR shall grant that applicant only the remaining credit
amount that would not exceed the $250,000 limit.
14. ADOR may verify that a water conservation system has been installed in the taxpayer’s residence. If you have questions regarding this credit, contact
Rosemary Soto at (602) 716-6595. Mail completed applications to:
Rosemary Soto, Economic Specialist
Office of Economic Research and Analysis
Arizona Department of Revenue
P.O. Box 25248
Phoenix, AZ 85002
34
- 35. How Much Water Does A Rain
Water Tank System Save
Anyway?
Using 1.5 sqft per tank gallon
and 9 inches a year:
1 - 4x10 => 8,500 gallons/yr
1 – 6x12 => 22,800 gallons/yr
11 – 6x8 => 167,400 gallons/yr
Assuming all harvested
rainwater can be used
between events
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
35
- 36. How Much ?????
Would You Believe:
A 4 foot diam. by 10 foot tall
diam.
stores 940 gallons and costs
about $2,100, or $2.25 a
gallon installed.
A 6 foot diam. by 12 foot tall
diam.
is 2,500 gallons and costs
about $3,400, or $1.36 a
gallon installed.
Eleven 6 foot diam. by 8 foot
diam.
tall tanks is about 18,000
gallons at roughly $1.20 a
gallon.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
36
- 37. The Future Of
Rainwater Collection
Drinking water on
tap (Off Grid Solar)
Water supply to
plumbing fixtures
in structures such
as toilets
Supplementing
groundwater
supply onsite
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
37
- 38. Residential Gray Water
Code
By 2010 all new
residential
construction must
provide gray water
stub outs.
Actual use of the
system is not
required.
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
38
- 39. Residential Gray Water System
General Permit
Definition of Gray Water: Wastewater, collected
separately from a sewage flow that originates
from a clothes washer, bathtub, shower, and
sink, but does not include wastewater from a
kitchen sink, dishwasher, or toilet.
A Type 1 General Permit allows private
residential direct reuse of gray water less than
400 gallons per day without notice to the
Department if all of the following conditions are
met: (A.A.C.R18-9-71 1)
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
Pima County Department of Environmental Quality 130 W Congress, 3rd Floor, Tucson, AZ 85701
General Permit BMPs
Follow these best management practices to comply with Arizona's rules for gray
water use First and foremost, avoid human contact with gray water, or soil irrigated with
gray water. You may use gray water for household gardening, composting, and lawn and
landscape irrigation, but use it in a way that it does not run off your own property. Do not
surface irrigate any plants that produce food, except for citrus and nut trees. Use only flood
or drip irrigation to water lawns and landscaping. Spraying gray water is prohibited. When
determining the location for your gray water irrigation, remember that it cannot be in a wash
or drainage way. Gray water may only be used in locations where groundwater is at least
five feet below the surface. Label pipes carrying gray water under pressure to eliminate
confusion between gray water and drinking water pipes. Cover, seal and secure storage
tanks to restrict access by small rodents and to control disease carrying insects such as
mosquitoes. Gray water cannot contain hazardous chemicals such as antifreeze, mothballs
and solvents. Do not include wash water from greasy or oily rags in your gray water. Gray
water from washing diapers or other infectious garments must be discharged to a residential
sewer or other wastewater facility, unless it can be disinfected prior to its use. Surface
accumulation of gray water must be kept to a minimum.
Should a backup occur, gray water must be disposed into your normal wastewater drain
system. To avoid such a backup, consider using a filtration system to reduce plugging and
extend the system’s lifetime. If you have a septic or other on-site wastewater disposal
system, your gray water use does not change that system’s design requirements for
capacity and reserve areas.
39
- 40. Typical Gray Water System
by the UPC Appendix G
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
www.watercasa.org
40
- 41. Modified Piping 2 Story Home
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
41
- 42. Subsurface Irrigation
Preferred But Not required
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
42
- 43. Surface Irrigation
Is Allowed If Standing Water Is
Avoided
“First and
foremost,
avoid human
contact with
gray
water, or soil
irrigated with
gray water.”
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
43
- 44. Design Considerations
Gray water will clog
the soil and prevent
percolation
Soil and
infrastructure
components must
be adequate to
withstand a high
amount of solids
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
44
- 45. Recap
Apply all of the aforementioned techniques
in your landscape and you also will see
the savings!
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
45
- 46. Contact Information:
Rodney Glassman
City of Tucson Ward 2
Rodney.Glassman@tucsonaz.gov
C. Alan Nichols, P.E., CEM, GBE, LEED AP
Al Nichols Engineering Inc.
alnichols@aol.com
Justin Cupp
Home Improvement and Maintenance, Inc.
rainwatercupp@yahoo.com
© copyrighted 2009 High Performance Building Science Workshop on 7/31/09
46