D-Spec is a drainage data specification originally developed for Brimbank, Hume, Whittlesea, and Wyndham City Councils by GISSA International.
The specification which incorporates Water Sensitive Urban Design elements is now managed by the A-SPEC consortium.
Whilst the specification is quite comprehensive with respect to drainage asset information, it does not make any prescription in regard to the surveyed accuracy of As-Constructed drainage data. The specification for accuracy appears to lie with individual councils who may require different standards of accuracy depending upon the data source.
Accuracy options include; unproven data encoded from design drawings; data encoded from low precision surveys; data encoded from high precision surveys.
To make good use of D-Spec data for engineering purposes, (in addition to Asset Management purposes), a council may consider employing specifications for required accuracy of As-Constructed D-Spec Data.