Ann: Mardie Project Update, page-149

Just coming back to you now as promised @MrCK re the mention of the considered 'design changes' in the 7th July announcement, 'Mardie Project Update'.

Got a bit distracted with the follow-up announcement. This is a bit longwinded, but bear with me.

As a reminder, this second paragraph was, for me, the main aspect of this announcement -
"Mardie is experiencing significant cost increases due to well publicised market conditions. In addition, BCIexpects some aspects of the Project design to change, in order to comply with third party approvals, and isconsidering some additional design changes to improve long term resilience of the Project to extremeweather events."

So clearly, this indicates to me that both BCI and their 'third parties' (?) have developed some learnings from the recent rain events and are now seeking changes to"improve long term resilience of the Project to extremeweather events".

So back to your post -
"Correct me if I'm wrong but the entire design is that all water entering the ponds will either be pumped from seawater, or rainfall. The outside walls of the ponds may see tidal flows but, short of a tsunami, no water will enter or leave these ponds. If this is correct then the only uncontrolled addition to the pond water levels will be rainfall..."

As I originally said, I agree to a point.

As we know, the western Pond Walls will ultimately be built to become one long 'sea wall', providing protection from (starting south) Pond 0/1 up to the northern part of the project, to Pond 9, mainly against tides and storm surges, etc. I don't believe these walls are the potential problem for BCI.

On the eastern side (inland) the ponds are essentially open and just finish with the rising land mass. On this eastern side of the ponds, roads will be built and there are also plans in place for flood mitigation purposes, to direct potential flood waters through the designed drainage channels, between the ponds and out to sea, but also around the project, again essentially to divert flood waters.

It is this area and aspect where I believe BCI will be focussing their 'design changes'.

Firstly, their are a multitude of 'third parties' that could potentially be involved, emanating out of these rain events. Having spent a fair amount of time reviewing a multitude of Mardie documents I've been able to cull them down to what i believe are the principal participants in this regard.
* EPA - Western Australia Environmental Protection Agency
* DWER - Western Australia Department of Water and Environmental Regulation
* PPA - Pilbara Port Authority
* PMPL - Pastoral Management PtyLtd (MardieStation)

Clearly, as a result of the heavy rains over the May period in particular, reviews have been conducted on planned flood mitigation plans and it would appear, based on the 'real life' experiences of these rain events, that further flood mitigation planning and design changes are required.

I would expect that, like me, you will be most surprised to learn that this 'flood risk' actually comes to the eastern side of the project, from the Fortescue River, which flows in a parallel direction to the Mardie layout, from South to North and empties into the ocean, about 15klms to the north east of the Mardie Projects NE boundary.

The specific areas I've identified as 'potentially' requiring further design changes are -
* The Flood drainage channels between Ponds 3/4 and 5/6 for potential overflows of flood water build-up into these ponds
* The Primary Salt Crystalliser Ponds,
* Mardie Rd, which runs alongside the Crystalliser Ponds and above Pond 9 and up to the proposed port,
* The causeway between Pond 9 and up to the proposed port.

See below map of Optimised layout.

So to support my theories, here below are just two hydrology flow maps from the vast stock of Mardie documents I have. There are so many of these maps I have simply chosen the most recent, best and worst modelling scenario positions, given their size and detail, based on the completed project modelling.

Please remember these are 'modelled' situations showing the potential impacts on a 'completed, (optimised) Mardie Project'.

1. Mardie Minimum Flood Model Example

2. Mardie Maximum Flood Model Example


Note the extensive, potential flooding coming from the Fortescue River, flowing westward towards the eastern flank of Mardie. Note the high dark blue flows around the areas I've identified above.

Now, remembering once again that these maps are of 'modelled flooding', and also taking into account Koi's allegation that there were reports of '5 inches of rain' falling in the Mardie Creek in late May (Mardie Creek is located on the coast, just to the west of the Port Causeway Road, shaped like a fish hook with a tail, just to the northwest of Ponds 8 & 9) it is quite possible that some of that heavy rain fell into the Fortescue River catchment area to Mardie's north east and flooded back onto the land of the 'undeveloped Mardie Project'.

If all this did occur, it would be very handy research and reference material for review, to implement changes to both existing road and flood mitigation designs.

In this 'hypothetical example' above, the survivability of the Port Causeway Road (given its relatively low design profile) could be, without doubt, of great interest to BCI and the PPA, in particular.

Be interested in your thoughts.

Cheers.