HomeMy WebLinkAbout8.2 Attch 4 Comments on Draft Ord Water Efficient Landscape Ord Comments on the City of Dublin's
Draft Water Efficient Landscape Ordinance
Comment from Jeff Lawrence of Braddock & Logan:
"The only item which we would request that the ordinance allow the use of subsurFace
irrigation for sod and plantings."
Response: The draft Ordinance does allow, without restrictions, the use of subsurface
irrigation for turf and shrub areas.
Comment from Jeff Lawrence of Braddock & Logan:
"Line 1.a.18 from heading G(Irrigation Plan) in the Landscape Documentation Package
(8.88.040) states "Narrow or irregularly shaped areas, including turf, fess than eight feet
in width in any direction shall be irrigated with subsurface irrigation or low volume
irrigation system." Braddock & Logan proposes future Positano neighfaorhaod parkway
strips contain lawn and low accent planting irrigated with subsurface irrigation.
Parkways and front yard landscape would be on the same irrigation system."
Response: This is allowed by the draft Ordinance provided hydrozones comply with
Section 8.88.040.G.1.b.
Comment from Jeff Lawrence of Braddock & Logan:
To fulfill the City's Maximum Applied Water Allowance requirements Braddock & Logan
proposes a design in which lawn makes up a maximum of 25% of the total front
landscape area per residence. The total landscape includes front yards as well as the
parkway strip area directly in front of each property. See attached diagram for sample
layout.
Response: There are no restrictions to the amount of turf to be used providing the
Estimated Total Water Use does not exceed the Maximum Applied Water Allowance
calculation as required by Sections 8.88.020 and 8.88.040.D. Turf is not allowed on
slopes greater than 25% where the toe of the slope is adjacent to an impermeable
hardscape as required by Section 8.88.040.F.1.a.4.
Comment from Aaron Ross-Swain of Standard Pacific:
still make the point that recycled water systems should be exempt from this
ordinance, as the goal of using recycled water is to use as much of it as possible to
avoid having to dump it into the Bay. North Marin Water District has exempted the use
of recycled water from their ordinance. The restrictions on having ta use low water use
plants should be lifted for recycled water, as the higher water use plants are more
adaptable to the high salt levels in recycled water. Lawn is the best, and most
successful, plant to use with recycled water."
Response: Recycled water is a limited resource and shoulcl be used efficiently. Areas
irrigated with recycled water qualify as Special Landscape Areas per Section 8.88.020
allowing use of full referenced evapotranspiration in the Maximum Applied Water
Allowance calculation per Section 8.88.D.3. Areas irrigated with recycled water are not
exempt from tF~e State Mode! Ordinance. North Marin Water District Ordinance does not
exempt use of recycled water as referenced.
There are no plant restrictions based on water use providing the Estimated Total Water
Use does not exceed the Maximum Applied Water Allowance calculation as required by
Sections 8.88.020 and 8.88.040.D. There have been many studies throughout California
ATTACHMENT 4
on selection of plants for recycled water and none suggest that higher water use plants
are more adaptable. See the hyperl'rnks below:
State Of Calif0l'llla - http:/lwww.water.ca.qov/wateruseefficiency/docs/recyluse.pdf
University of California Davis -
http://slosson.ucdavis.edu/Landscape Pfant Selection Guide for Recycled Water Irrigation/
City of SBnta ROSa - http://ci.santa-rosa.ca.us/doclib/Documents/ut rw PlantList.pdf
Clty Of Santa Bal'ba1'a - http://www.santabarbaraca.qovlNR/rdonlvres/F1 EDB7DG5dAA-4614-A6DC-
CC7C7ED561 CB/O/Recvcledwaterplantlistandsummarv.pdf
Comment from Aaron Ross-Swain of Standard Pacific:
"Pushing the use of subsurface drip tubing, or even surface drip, is problematic,
because of the high levels of suspended solids and high levels of salts and other
elements in recycled water, which tend to clag the systems, and require the use of
sophisticated and costly filtering systems."
Response: Filtration of low volume irrigation, covering the irrigation emiss'ron devices
with soil or mulch, and automatic flush valves limit the tendency of clogging. Filtratian
and flush valves are recommended and typically useci on such systems.
Comment from Aaron Ross-Swain of Standard Pacific:
"Requiring the use of 3" of mulch will cause stem and crown rot in the plants, and will kill
them. This has been observed on several installations, and some agencies have
reduced their requirement back to 2", as it has always been. Every horticultura!
consultant I have talked to agrees with this. Why would the City require something that
would kill what they are requiring to be installed?"
Response: The current City Ordinance requires 3 inches of mulch in pfanted areas.
Bay-Friendly Landscape Guidelines recommend 3 inches of mulch. Alameda
Countywide Clean Water Program G.3 Stormwater Technical Guidance Appendix L
requires 3 inches of mulch.
The benefits of mulch includes: reduce moisture evaporation; reduce of soil erosion; can
improve soil aeration; improve soil eonditions; minimize weed competition; keep soil
cooler in the summer and warmer in the winter; and reduce soil compaction caused by
precipitation. Mulch shauld not be allowed to come in contact with a plant's trunk and
kept away from the root crown to prevent collar rot.
Prepared by: Brian Dutchover
Dutchover & Associates
March 24, 2011