Appendix A
Lower Colorado River Authority
Suggested Conservation and Landscape Guidelines
With Rationale and Talking Points
- Landscape irrigation systems shall not be mandatory.
(Many HOA’s
and POA’s
currently require irrigationsystems. Studies have shown a
substantial increase in water use associated with automatic irrigation
systems, including a 1999
City of Austin study demonstrating a 83% in water consumption in home
with in-ground irrigation systems
over homes without.)
- Landscape irrigation systems,
if installed, will be required to include the
following water conservation features:
- Rain and/or moisture sensors (According to Rain Bird, rain sensors can
result in at least 15-20% in water
savings.)
- Backflow prevention device installed in accordance with applicable
state laws
- Pressure reducing valve and/or remote control valves for each station
with flow control
(Over-pressurized systems cause fogging which can result in up to 25%
of
water being lost to wind and evaporation)
- Pressure reducing valve, for which pressure reducing valve installed
in-line at the meter and serving house as well as irrigation system,
is
acceptable.
- Zoning of irrigation system based on plant water requirements.
(Mixing different plant types (such as turf with shrubs) in the same
irrigation zone results in over or under-watering some of the plants.
Because most people water for the “dry-spot,” mixed zones
most often
result in over-watering)
- Multiple cycle controllers with an irrigation water budget feature.
(These controllers allow system to “cycle and soak” which
decreases
runoff. They also allow the system to be easily rescheduled to more
closely match seasonal water needs, cutting back on water by 50% in
spring and fall relative to summer application.)
- Minimization of overspray onto hardscapes by design, maintenance
and scheduling practices. Due to overspray, subsurface drip irrigation
is encouraged but not required.
- Low volume irrigation shall be installed in areas less than 10 feet
wide, such as median strips, and parking islands.
(Narrow areas are extremely difficult to water without overspray (and
runoff) using pop-up spray heads. In addition, sprinkler heads adjacent
to sidewalks
and driveways are often broken or damaged by vehicle and foot traffic.
Broken
heads eliminate the potential for the area to be watered efficiently.)
- Contractors installing irrigation systems must provide system design
plans to the
homeowner. And scheduling recommendations shall be posted in
or near the
irrigation controller box.
(Without basic information about the irrigation system, a new
homeowner would have to do an
extensive audit of the system to manage it efficiently. Once
the pipes are covered in the ground,
it becomes very difficult to understand the layout of the system
without a design plan.)
- Irrigation systems in common areas will
be monitored once a month, and any
repairs shall be made in a timely manner
(Sprinkler heads are commonly broken by mowers, pedestrians and
other traffic. A system with
broken heads cannot operate efficiently, and can result in thousands
of gallons of runoff every
time the system operates.)
- Spray irrigation for each home/business
shall be limited to 2.5 times the
foundation footprint, with a 12,000 sq foot maximum. The footprint
may
include both the house and the garage, but not the driveway or
patio. (For every 1000 square feet that receives one inch of
water (the weekly recommended amount
during the summer months), about 600 gallons of water is used.
That means that a 12,000 sq
foot irrigated area will receive about 7200 gallons of water
per week during the summer following
the recommended watering schedule. Limiting the area of irrigated
landscape to 2.5 times the
footprint of the home allows for a more intensively landscaped
area around the home without
having vast irrigated areas.)
- Irrigated ornamental common areas
at entryways and intersections shall follow
the guidelines outlined below (unless irrigation of reclaimed
water is necessary
to meet regulatory requirements)
- Irrigated landscaped area shall be limited:
- i. Subdivision entryway landscaping shall not exceed 6000 square
feet.
- ii. Landscaping at intersections within the subdivision shall not
exceed 3000 square feet.
(This allows for irrigated landscape focal points in the subdivision
without vast
irrigated common areas)
- Irrigation of common areas shall occur between the hours of 7:00
PM and 10:00
AM. There shall be NO WATERING between the hours of 10:00 AM
and 7:00 PM unless irrigation of reclaimed water during the day
is necessary to meet
regulatory requirements.
(Watering between dusk and dawn reduces loss to evaporation which
can be as high as 40%
during the heat of summer.)
- All irrigated and newly planted turf
areas will have a minimum soil depth of 6 to
8 inches. Builders and owners will import soil if needed to achieve
sufficient soil
depth. Soil in these areas may be either native soil from the
site or imported,
improved soil. Improved soil will be a mix of no less than twenty
percent compost blended with sand and loam. Caliche shall not be
considered as soil.
(In the turf type used in central Texas, the majority of roots
grow in the top 4-6 inches of soil. A
recent study conducted by TAMU and SAWS tested the drought tolerance
of the main turf types
during 60 days without water on 4 inches of soil and on unlimited
soil depth. All of the turf planted
on 4 inches of soil died during the 60 days without water. On
deep soil, all of the turf rebounded
except some varieties of St. Augustine, demonstrating the importance
of soil depth on turf survival
and health. Additionally, according to the Irrigation Association,
up to a 50% water savings can be
achieved by increasing soil depth for a turf area from four inches
to eight inches.
Compost increases the water holding capacity of soil by about
16,000 gallons per acre foot for
each 1% organic matter. This decreases runoff and improves plant
health.)
- Native soil shall be stockpiled and reused on site.
- Topsoil that is
added to the site shall be incorporated in a 2 to 3 inch scarified
transition layer to improve drainage.
- In new homes, no more than
fifty percent of the landscape may be planted in
turf.
(Turf is the most watered component of the landscape. Limiting
turf area reduces outdoor water
use.)
- All new turfgrass installed shall have summer dormancy capabilities.
(Turf with summer dormancy capabilities insures that landscapes
will survive under mandatory
water restrictions.)
- Shrubs and flowers should be selected from
native and adapted plant list
approved by the LCRA or _________ County/City.
(Using native and well adapted plants in the landscape reduces
the need for supplemental
water and chemicals.)
- Invasive plants listed in this document shall
not be used. (“Problems
caused by invasive plants cost billions to the global economy
every year, mainly from loss of grazing land and reduced crop
productivity due to non-native weeds. The cost to the
United States alone is an estimated $137 billion a year in management
and missed economic
gain. Ecologically, they can disrupt ecosystem services and disrupt
communities by being spacedominant
or through impacts on keystone native species. At their worst,
invasive plants have the
ability to degrade whole ecosystems, both terrestrial and aquatic.” Source:
Wikipedia)
- Landscape companies providing maintenance on all common
areas and individual landscapes must only use integrated pest management
(IPM) to
minimize exposure of storm water runoff to chemicals (fertilizers,
herbicides and
pesticides). IPM prohibits routine and “preventive” broadcast
application of
broad-sprectrum chemical pesticides in the absence of evidence
of active pests.
IPM techniques include the following:
- Accurately identify pest or disease problem before considering
treatment
- Explore cultural or mechanical controls (i.e. modification
of irrigation, pruning, etc)
- Look for biological control options (i.e. predatory insects
for pest control, Bt
for caterpillar control, etc)
- Consider chemical control only if other options fail
- Utilize least-toxic and targeted chemical controls
- Baits are preferable to broad-spectrum chemical application
- Follow instructions on chemical labels exactly
- Perform periodic monitoring for early detection of potential
problems
- Landscape companies providing maintenance on all common areas and
individual landscapes must only use the following fertilizer
practices:
- Fertilization of turf areas shall not be required
- In turf areas that are to be fertilized, natural or certified
organic fertilizers
with less than 4% phosphorus shall be used.
- Fertilizer shall be applied at a rate of ½ pound
of nitrogen per 1000 square
feet, not to exceed a total of one pound of nitrogen
per 1000 square feet per
year. (Phosphorus accumulates in alkaline Central
Texas soils, and there is generally not a need to add
large amounts of phosphorus in the form of fertilizer. Nitrogen
is limited in Central Texas soils and
does not accumulate. Although adding small amounts of nitrogen
can be beneficial to plants, excess
soluble nitrogen runs off or leaches through the soil as a potential
pollutant to ground and surface
water.)
- Builders or property managers must present guidelines
for IPM plans and
fertilizer practices meeting the deed restriction requirements
to home buyers at
the time of closing.
(These guidelines are contained in Grow Green fact sheets available
from LCRA)
- As passed by HB 645 in the 2003 Texas Legislative
session, the homeowners or
property owners association documents (including declaration
of covenants, articles of incorporation, bylaws, or any other
document of the association which
binds members of the association) shall not restrict the property
owner from:
- implementing measures promoting solid-waste composting of vegetation,
including grass clippings, leaves or brush, or leaving grass
clippings uncollected on grass;
- installing rain barrels or a rainwater harvesting system;
or
- implementing efficient irrigation systems, including underground
drip or
other drip systems.
- The homeowners or property owners association documents (including
declaration of covenants, articles of incorporation, bylaws,
or any other
document of the association which binds members of the association)
shall not
require:
- a defined irrigation schedule specified by the association except
if that
defined irrigation schedule is mandated by the association’s
water supplier in order to curtail outdoor water use.
- maintenance of the landscape to a specified level that
requires the
property owner to irrigate his or her landscape.
- installation or maintenance any specific variety or limited
choice of
varieties of turf grass.
- the homeowner to install a minimum percentage of turf
in the landscape.
(Homeowner association rules should not be in conflict
with water conservation
measures)
- A minimum of two inches of mulch shall be maintained in all shrub
and bed
areas.
(Mulch helps retain soil moisture, moderated soil temperatures,
and helps prevent soil
erosion)
- Encourage rainwater gutters sized appropriately to
catch rainwater from the
rooftop.
- Encourages galvanized metal roofs to facilitate rainwater
storage.
- Encourage installation of water efficient toilets, dishwashers
and clothes
washers.
- Encourage incorporation of treated effluent/rain water/storm
water systems to
meet certain irrigation water needs, including common areas.
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