Timaru District Council

Source Documents

These are the council documents used to build the TDC calculator. If a link is broken, the document may have moved on the council website.

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Stormwater Management Acceptable Solution No. 1, Version 2 (Feb 2024)

PDF Primary Source

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TDC Stormwater Information Page

Council website - may contain updated links if documents above have moved.

Calculation Methodology

Retention

25% of tank volume

Method

Table lookup. 4 rows covering 30-250m2 roof. Sub-locations: Timaru, Geraldine, Temuka/Pleasant Point with different orifice sizes.

Design Requirements

• Tank must be above ground (slimline or round)
• Leaf diverter required on downpipe to tank
• Overflow must NOT connect to main stormwater system
• Overflow must discharge to visible overland flow path
• Total site impervious surface must be less than 70%
• Orifice diameter and height per Table 1 exactly
• Residential development only

Submission