The habitat extension consists of two components, the Marsh Street Habitat which contains the ponds and the Southern Frog Corridor which connects the Marsh Street Habitat to the existing habitat of the Arncliffe GGBF. See the page WestConnex, Design of Habitat Extension for more detail.
Progress on the habitat extension must obviously be measured against the conditions with which the project has been approved. Some sections of screenshots from the WestConnex New M5 Instrument of Approval are below:
What this means is that the Marsh Street Habitat, which is mentioned in both plans, must be completed within one year of construction (of the new M5) while the Southern Frog Corridor which is not mentioned in the second plan has no specific timing requirement on it although it is probably fair to say that the New M5 project could not have been considered complete until the Southern Frog Corridor has been established.
As the end date for establishment of the Mash Street Habitat is defined in terms of the start of construction of the New M5, we need to establish when construction actually started. The Sydney Motorway Corporation Annual Review 2016 which in the section "The year in review - highlights" under "July 2016" lists as one of the hightlights: "WestConnex New M5 construction commenced". Below is a section of a screen shot I took from the PDF document.
WestConnex considers New M5 construction to have started in November 2016. I looked at area around the RTA habitat on June 29, 2016. It was clear that New M5 related work had already commenced. But WestConnex considers all work prior to November to be site preparation work. I find this distinction unconvincing because it doesn't make any difference to the frogs whether they lose habitat to site preparation or to construction. Here is the relevant text from an email I got from the community relations team on January 23, 2017:
Construction of the New M5 started in November 2016 (please find attached a notification to that affect).
Activities undertaken prior to this were part of site establishment in preparation for the start of construction (see site establishment notification attached).
Construction of the ponds are scheduled to begin in the first quarter of this year.
Two documents were attached which I saved: Arncliffe construction update notification and Site establishment - Arncliffe notification FINAL The documents are not explicit about when construction started and in any case refer to site preparation and construction activities in Arncliffe. The required completion time is defined in terms of the start of construction and not the start of construction in Arncliffe.
But even going with what WestConnex said, the Marsh Street habitat needed to be finished by no later than November 2017.