MORE STUFF ON CHASE RIVER DAMS
Lawrence Rieper : jULY, 2013
In 1903, the following city reservoirs were listed, along with their capacities:
- #1= 8 million gallons (after 1910 = 14 million gallons);
- #2 = 11 million gallons;
- #4 = 71 million gallons;
- #6 = 22 million gallons
(City of Nanaimo, Finance Department, Series 6, Published Financial Statements 1901- 1932, Nanaimo Community Archives)
#1is currently the city reservoir, and #2 is the Upper Colliery Dam on the other side of
Nanaimo Lakes Road. #4 is now known as Morrell Lake or Power Line Dam.. It is believed that #6 was until not so long ago on the Chase River, south of the Rifle Range and north of the Fish & Game Club (It supplied water to the City by a 10-inch pipe).
In 1976, the following reservoirs are listed, along with their surface areas:
- #1 = 3.83 acres (Sect. 1, Nanaimo Dist. & Sect. 4, Range 8, Mountain Dist.)
- #2 = 5.89 acres (Sect. 3 & 4, Range 8, Mountain Dist.)
- #3 = 6.34 acres (Sect. 1 & 2, Range 7, Mountain Dist.)
- #4 = 18..64 acres (Sect. 7 & 8, Range 9, & Sect. 7, Range 8, Mountain Dist.)
- #5 = 7.05 acres (Sect. 1, Nanaimo Dist. & Sect. 5, Range 8, Mountain Dist.)
(Taken from a Certificate of Encumbrance dated 26th August 1976, NCA)
Again, #1, 2 and 4 are straightforward. #3 appears to be #6 renumbered. #5 is an oddity, an allocated space between #1 and Middle Colliery dams (Harewood Improvement District, 1970 Water System Map, NCA) .Some present day covered reservoirs are numbered too: #2=Lost Lake; #3A/B=College Park; #4 = Rod Glen; #7 = Tanya Drive.
From the above, there is historical evidence of a number of extra dams feeding into the Chase River. The older ones would originally have been wooden structures.#1, which dates from 1887, was rebuilt with concrete in 1910. #2 was rebuilt after collapsing in 1921. #4 was rebuilt in 1985.The last two are earth berms.
I surmised in my, “Deny. Deny, Deny” that dotted line shown in the 1963 Chase River Inundation Study, from Morrell to Westwood Lake might indicate water flowing from Westwood into Morrell. Having looked more closely at the topography, I believe the opposite is true. If the two dams at the north end of Morrell Lake were to break, water would flow towards Westwood Lake, but possibly dissipate en route.
In 2004, Morrell Lake was drained in about two weeks using a 12 inch pipe. The water flowed southeast along the power line, then east at ‘MC’ gate, under the Yew Trail bridge and under Nanaimo Lakes Road into the Chase river. It filled up within the first winter.. It is now necessary that the lake be drained again soon.
There has been consultation with the city of Nanaimo and Dam Safety Branch regarding timing so as not to affect water flow in the Chase River and Colliery dams. Quite soon, the Western Toads (Anaxyrus Boreas) will develop from tadpoles and move from the lake into the woods, an optimum time for draining Morrell Lake. Whether or not the water in Morrell Lake can significantly affect the downstream, CON and DSB seem concerned about the possibility.
There are Red-Legged Frogs (Rana Aurora) at Morrell Sanctuary. The 1980, “An Ecological Survey of the Harewood Colliery Dam Park”(NCA) lists Red-Legged Frogs at Colliery Park.
Like the Western Toad, these amphibians are listed under Canada’s Species At Risk Act, Schedule 1-Special Concern. Since there is a waterway linking Morrell and Colliery lakes, it isn’t much of a stretch to anticipate Western Toads at Colliery Park too. There is also the possibility of the herb Beggarticks, another Species of Special Concern and Townsend Moles, an endangered species, at Colliery Park.
Not very long ago I was asked about a waterway flowing from Westwood Lake, through Nanaimo Military Camp to Chase River. I didn’t think it very likely. However the 1944 map of the camp (NCA) shows an un-named creek running from the old ammunition bunkers nearest to Westwood Lake through the southwestern section of the camp, under Nanaimo Lakes Road and into the Lower Colliery Lake. It is also partly shown on more recent city maps. It is not clear whether or not water could flow from Westwood Lake.
In the Nanaimo Daily Free Press for April 28th, 1960, under the heading “Harewood Buys Park For $24,000 Over 20 Years,” was the following, “………Colliery dams, covering 60 acres, which have been acquired this month for $24,000 from the Canadian Collieries after being leased for three years……….Improvements at the dams include stocking with fish, construction of truck bridge and floodgates to regulate flow, development of a gravel pit, trails, diving boards, beach and other facilities to improve the area” The park had been leased for three years previously. It has been rumoured that special considerations were placed on the deal when the dams were purchase, or when they were handed over to the City of Nanaimo at amalgamation. The A.F.Buckham Papers at BC Archives contain a number of correspondence files that might have some mention of the sale. The question remains whether or not the safety issue that staff have been pushing, would trump a legal responsibility to maintain the dams in perpetuity, always supposing such a document exists, or could some compromise be found?
It has been shown that some of the speculation in the 2010 Seismic Hazard Assessment Middle & Lower Chase River Dams was flawed, particularly regarding lack of rebar in the concrete and not being attached to bedrock. However it is the 2012 Chase River Dam Breach Flood Inundation Study that is the problem. It assumes that the dams would collapse very quickly by earthquake or flood and a huge surge of water would flow down the Chase River killing over a hundred people. I suggest thoroughly analyzing the 1963 Chase River Inundation Study and the 2002 Chase River Incremental Damage Assessment in comparison to the 2012 study. Only the maps of the 1963 (and BC Archives does not permit me to publicize it) and 2002 studies have ever been seen (City website -Hazards). We must demand the full reports be made public. They both model breaches of more dams on the Chase River system with the release of more water than the 2012 study. We need to know what conclusions were drawn from these earlier studies. If they are radically at odds with the latest study, then serious doubts must be cast on the findings of the 2012 inundation study. I have also shown in my “Is Nanaimo Safe?” that there is reason to question the 2012 Population At Risk and subsequent death toll. What was done at Westwood Dam could be done for the Lower Colliery Dam to slow the release of water to a manageable level, along with other mitigation options.
Lawrence Rieper: July, 2013
Posts and Comments on Nanaimo Governance 
Lawrence, I have a feeling you are confusing #2 (South Forks Dam) calling it Upper Colliery Dam. Surely Upper Colliery Dam is nowhere near 5.89 acres. Upper Colliery Dam is much smaller than the #1 Reservoir, which you have shown as being 3.83 acres. The 1921 dam breach was #2 (South Forks Dam) on Nanaimo River, and building of a new concrete arch dam at that site was completed in 1931 at a cost of 105,000. I sure would like to see those 1963 inundation maps.
Thanks Lawrence for the excellent research.
“……. the 2012 Chase River Dam Breach Flood Inundation Study ……… is the problem.
It assumes that the dams would collapse very quickly by earthquake or flood and a huge surge of water would flow down the Chase River killing over a hundred people.”
It is important to understand that the “Inundation Study” is a strategy to rationalize future actions, i.e. the award of a demolition contract! The public response has been one of shock at how poorly we are served by civic employees and elected officials. Colliery Dams Park is a public asset owned by the community, it is not a “corporate asset” that can be disposed of through secret “in camera” decisions. The question remains, how to best ensure the future of Colliery Dams Park.
Hi Tom, Actually, I don’t feel that I’m confused. I first wrote about the 1921 flood in November 2012. My comments are available on this web site as “Some Observations on the Decision to Remove Colliery Park Dams”. I have just revisited the Nanaimo Free Press for 29th October 1921, and can see how South Forks Dam could be confused with #2 Reservoir, but they are quite separate locations. Water is piped from South Forks to #1 Reservoir (across Nanaimo Lakes Road from #2 Reservoir. The road bridge carries the pipes. Both South Forks Dam and #2 Reservoir were damaged by the flood in 1921. I invite you to re-read the story. Furthermore, I am quite confident from all the references and maps that I have seen in the last nine months (and longer) that #2 Reservoir is Upper Colliery Dam. It is slightly larger in area than #1 Reservoir, although over more than a century its surface area and volume has changed a bit. For comparison, Westwood Lake is well over 130 acres, and its volume is slightly more than South Forks Dam. I cannot find a surface area for its lake, but I suspect it is similar. I hope this clears up the matter for you. All the best, Lawrence.
Thanks, you definitely cleared things up for me. The main reason I was mistaken was because I was unaware #2 reservoir (upper colliery dam) was damaged in the flood, and the numbering of dams and resulting reservoirs don’t correspond. I draw a great deal of knowledge from your posts, keep up the good work.
http://www.theglobeandmail.com/news/british-columbia/nanaimo-city-council-abandons-plans-to-remove-popular-dams/article13658543/
Press Release:
The Colliery Dam Park Preservation Society would like to thank the City staff and Council for developing a plan which will provide immediate risk mitigation and give the City and other concerned stakeholders time to discuss and develop long term mitigation solutions. We are optimistic that we are on a progressive path towards a constructive plan for preserving the heritage value and social benefits of having these dams in the park for the future.
The short term risk mitigation developed for the dams is a very thorough plan and one that may produce the added bonus of being a template for an emergency plan for the whole city. As any event that would be of a scale that would cause the dams to fail would also be one that would cause wide spread devastation in the city, creating a city wide emergency preparedness plan would be a sensible move. We are grateful that the people in Harewood will have the benefit of this plan but we think all of Nanaimo residents should also have the same consideration.
As we move forward the Colliery Dam Park Preservation Society is hopeful that common sense and cost effective methods will be pursued, while keeping residents safe from actual and real risks as a priority. As there is new information regarding the status of the dams, which should decrease the consequence rating, common sense would indicate repairing the dams could be a fairly straight forward and cost acceptable option.
The Colliery Dam Park Preservation Society has attempted throughout this process to support the efficient use of tax dollars. We are hopeful that this will be a goal that we all work towards as we develop a plan for the future of the middle and lower Colliery dams. Our community has worked tirelessly and without cost to the city to provide research information that would assist City staff and we look forward to combining our resources with those of the City to find solutions. The Colliery Dam Park Preservation Society supports the safe upgrading of the middle and lower Colliery dams in a manner that uses practical methods and is not only mindful of tax dollars spent but also considers other important factors such as the values and needs of other major stakeholders.
The Colliery Dam Park Preservation Society +1