Please note that the date was omitted from the cover of the first print run of this guideline.
If your copy does not show the date on the cover or inside cover please note that the date for this issue is May 2020.
An error has been identified in the recently published Guidelines on Tailings Dams – Revision 1 (July 2019).
The error is in Figure 5 – Flow Sheet for Tailings Dam Spillway and Storage Design on page 33. The third box up from the bottom of this figure references Table 5 when this should be Table 6, see below.
Design spillway in accordance with
Dam Failure Consequence Category
Table 6
The full page with the correction applied can be viewed and downloaded via the link below.
Corrected page from Tailings Guidelines – Revision 1 – 04-09-19
The addendum link below now includes the correction.
[su_box title=”Please note: ” style=”soft” box_color=”#081758″]This amendment has been incorporated into copies of the Guidelines on Tailings Dams – Planning, Design, Construction, Operation and Closure – Revision 1 (July 2019) reprinted in 2020. Noted on the inside cover page as (2020 REPRINT WITH AMENDMENTS). [/su_box]
Tailings Guideline Addendum July 2019 v2
Please note: If the version you are using is dated May 2019 it won’t include this correction so please ensure it is applied.
A query was raised by one of the ANCOLD Members regarding a potential error in the recently published ANCOLD Guidelines for Design of Dams and Appurtenant Structures for Earthquake. The query related to the last sentence of the last paragraph of Commentary Section ‘C4.5.1.1 Gravity Dams’. This item has been assessed and it was found that the Guideline is in error and a change needs to be made. The error is in a single number in the sentence which instead of being 0.75 should have read 0.3. The sentence needs to be changed as follows:
Original – C4.5.1.1 Gravity Dams – last sentence
The value of the DCR should not exceed 2 for a very limited cumulative non-linear duration, and it reduces to 1 for a cumulative non-linear duration of 0.75 second. The DCR method is further described in USACE (2003b).
Revised – C4.5.1.1 Gravity Dams – last sentence
The value of the DCR should not exceed 2 for a very limited cumulative non-linear duration, and it reduces to 1 for a cumulative non-linear duration of 0.3 second. The DCR method is further described in USACE (2003b).
[su_box title=”Please note: ” style=”soft” box_color=”#081758″]This amendment has been incorporated into copies of the Guidelines for Design of Dams and Appurtenant Structures for Earthquake (2019) reprint dated July 2019. [/su_box]
The Queensland Dam Safety Regulator for water dams is now;
Queensland Department of Energy and Water Supply
Water Planning and Regulation
PO Box 15456, City East QLD 4002
Whilst the Concrete Faced Rockfill Dams Guideline (1991) was well written and representative of the state of knowledge at the time it now contains a few potentially misleading statements and some sections are now outdated.
There are now better references available for Dam Engineers involved in CFRDs.
In addition there are few CFRDs being constructed in Australia now.
For these reasons ANCOLD has decided not to update the old CFRD guideline and will withdraw it from sale.
ANCOLD suggests that the following references may be useful to refer to instead. There would also be other useful references such as more recent Chinese Symposium volumes.
A review has been undertaken into the rationale behind the change in the category of two orders of magnitude for ‘Medium’ Severity of Damage and Potential Loss of Life from ≥1 to <50 with a subsequent change in Category from High C to High A. The review concluded that there was justification for the threshold of PLL ≥5 to <50 and within the range 5 to 10 with ‘Medium’ severity of damage, that the category could be reduced to High B. For PLL ≥ 10, the category will remain at High A. The revised Table 4 and associated notes below should replace the existing Table 4 and Note 1 of the September 2012 Guidelines on the Consequence Category for Dams.
TABLE 4 – (As revised October 2015)
CONSEQUENCE CATEGORIES (based on PLL)
| Potential Loss of Life (PLL) | Severity of Damage and Loss | |||
| Minor | Medium | Major | Catastrophic | |
| <0.1 | Very Low | Low | Significant | High C |
| ≥0.1 to <1 | Significant | Significant | High C | High B |
| ≥1 to <5 | (Note 1) | High C | High B | High A |
| ≥5 to <50 | High A(Note 2) | High A | Extreme | |
| ≥50 | (Note 1) | Extreme | Extreme | |
Note 1: With a PLL equal to or greater than one (1), it is unlikely Damage will be minor. Similarly with a PLL in excess of 50 it is unlikely Damage will be classified as Medium.
Note 2: Where PLL is in the range ≥5 to<10, the Category level can be reduced to High B.
[su_box title=”Please note: ” style=”soft” box_color=”#081758″]This amendment has been incorporated into copies of Guidelines on the Consequence Categories for Dams (2012) reprinted in 2020. Noted on the inside cover page as (2020 REPRINT WITH AMENDMENTS). [/su_box]
PLEASE NOTE: The 2014 ANCOLD publication titled ‘Regulation and Practice for the Environmental Management of Dams in Australia’ has been produced that supplements these ‘Guidelines on the Environmental Management of Dams (2001)’.
The 2014 document extends and complements the scope of the 2001 Guidelines by focusing on current investigation and regulatory approval processes. Additionally, it provides a series of Practice Notes in Section B that document current knowledge on a range of key environmental issues of concern to dam owners/operators.
The new document does however supersede and/or update some of the material in the 2001 guideline. The significant relevant areas are as follows:
• Section 2 (2014) expands and updates Section 3 (2001)
• Section 3 (2014) supersedes Section 5.6 (2001)
• Section 4 (2014) supersedes Section 5.5 and Appendix E (2001)
• Section 5 (2014) largely supersedes Sections 5.2 and 5.7 (2001).
Please note the following corrections to the guidelines:
“Reasonably practicable” is a narrower term than “physically possible” and seems to me to imply that a computation must be made by the owner in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed on the other, and that if it be shown that there is a gross disproportion between them – the risk being insignificant in relation to the sacrifice – the defendants discharge the onus on them.
This is the quote from the judgement in the Edwards versus The National Coal Board case of 1949 in the United Kingdom.
ANCOLD is an incorporated voluntary association of organisations and individual professionals with an interest in dams in Australia.
