Difference between revisions of "Planters: Sizing"

From LID SWM Planning and Design Guide
Jump to navigation Jump to search
m
m
Line 29: Line 29:
|-
|-
| Pipe diameter reservoir
| Pipe diameter reservoir
| Is equal to underdrain pipe diameter
| Is equal to underdrain [[pipe]] diameter
| 0.4  
| 0.4  
|-
|-
| Pipe bedding (''d<sub>b</sub>'')
| [[Choker course|Pipe bedding]] (''d<sub>b</sub>'')
| 50 mm (although commonly omitted altogether).  
| 50 mm (although commonly omitted altogether).  
| 0.4
| 0.4

Revision as of 17:58, 19 March 2018

A flow-through planter comprises a ponding zone, mulch layer, filter media for planting, and a supporting gravel drainage layer

This article is specific to Flow-through stormwater planters, vegetated systems that do not infiltrate water to the native soil.
If you are designing a planted system which does infiltrate water, see advice on Bioretention: Sizing.

The dimensions of a stormwater planter are largely predetermined according to the function of the component. As they do not contain a storage reservoir the planters rely more upon careful selection of materials. Both the filter media and the perforations of the pipe play critical roles for flow control.

Component Recommended depth (with underdrain pipe) Typical void ratio (VR)
Ponding (dp) ≥ 300 mm 1
Mulch 75 ± 25 mm
  • 0.7 for wood based
  • 0.4 for aggregate
filter media (dm)
  • 300 mm to support turf grass (and accept only rainwater/roof runoff)
  • 600 mm to support flowering perennials and decorative grasses
  • 1000 mm to support trees
0.3
Pipe diameter reservoir Is equal to underdrain pipe diameter 0.4
Pipe bedding (db) 50 mm (although commonly omitted altogether). 0.4


Calculate the maximum overall depth[edit]