Design Guide

_____________________________________________________________Landscape Dripline Design
■ General Design Parameters
NOTES:
Potable water, the most common type of water used in landscape
applications, has relatively little debris and chemical contamination.
Therefore, it only needs to be filtered with a screen or disk filter. With
other water sources, it is advisable to obtain a water analysis prior to
designing and installing the system. Some of the important parameters
are:
• Total dissolved solids (tds)
• Iron content
• Calcium, magnesium, sulfates, bicarbonates and hardness
• Chemical compounds present, bod and tss (grey water, industrial
treated water and recycled water)
• The types and amount of sediment present (irrigation district water
and well water)
Soil Types and Preparation
For design purposes, soil classifications of clay (heavy), loam (medium)
and sand (light) are used in conjunction with plant types to determine
the emitter and lateral spacings necessary to provide a uniform subsur-
face soil moisture regime for the plant material.
As with all types of landscape irrigation systems, properly prepared soil is
necessary to provide a homogenous bed for proper plant establishment,
plant growth and uniform water distribution. Heavily compacted and
layered soils should be ripped and tilled at a uniform eight- to twelve-
inch depth to improve the consistency and tilth of the soil.
Soil and water analyses are recommended when the soil texture, soil Ph
and water quality are in doubt. This is necessary in order to recommend
soil amendments and water treatment when required. If possible,
pre-irrigate the installation site when the soil is too dry to till and trench.
Plant Material Classification and Planting Layouts
Emitter and lateral spacings are determined by soil and plant material
classifications. For design purposes, two general plant classifications are
used: 1) trees, shrubs and ground cover, and 2) turf. Turf plantings have
a much more intense and compact root structure, thus requiring a closer
emitter and lateral spacing to efficiently irrigate these areas.
Planting layouts determine the size and type of irrigation design
necessary to provide uniform moisture distribution. Individual or isolated
planting areas separated by large expanses of unplanted areas or
hardscapes require individual grids that provide moisture within the
foliage canopy of the landscaped area.
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