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EnerduMississippi Mills Riverkeepers respond to Enerdu expansion

Mississippi Mills Riverkeepers respond to Enerdu expansion

Enerdu recently provided its proposal for expansion of the generating station at the top of Almonte Falls on the WESA website. The proposal has been reviewed by the Mississippi Mills Riverkeepers Association who provided this response to Project Manager Ron Campbell and Enerdu's environmental scientist Pilar de Pedro. 


July 5, 2012

Mr Ron Campbell

Project Manager

Enerdu Power Project

Enerdu Power Systems

9094 Cavanagh Road

Ashton, ONK0A 1B0


Ms. Pilar DePedro

Environmental Scientist

OEL-HydroSys Inc.

3108 Carp Rd

Carp, ONK0A 1L0


Dear Mr. Campbell and Ms. DePedro:

Thank you for the Enerdu GS Expansion and Redevelopment Project Description, recently made available to the general public.

Our committee has read this document carefully and we have a number of concerns and questions, which will be enumerated below under separate headings.

 1. Affected Areas

Studies conducted in 2011 by both the Mississippi Field Naturalists and the Mississippi Valley Conservation Authority (MVCA) clearly showed that current Enerdu operating practices affect water levels to the dam at Appleton. The affected area of this project includes the river course to the base of the Appleton power station or waterfalls.

 2. Zone of Impact

 Throughout the report, only the immediate area of the new power plant is considered at risk of potential environmental impact. The drawings appear to indicate the proposed new weir structure, with mechanically adjustable gates, has a maximum height of 118.0 metres (m), Above Sea Level (ASL). Some references on the drawings show 118.0 m as Normal Operating Water Level (NOWL). We believe that level has been taken from the Mississippi River Water Management Plan (MRWMP) and is not, as we understand the intent of the plan, the normal operating level. It is our contention that 118.0 m is in fact the maximum compliance level. The water management strategy in the MRWMP calls for maintaining river levels between the range of 117.2 m to 117.7 m. The current Enerdu plant appears to operate roughly in this range, but with periods in excess of these compliance levels.

Contrary to the claim in the Enerdu Expansion Plan document, the Appleton Wetland is a provincially significant wetland designated ANSI (area of natural scientific interest) by the Ontario Ministry of Natural Resources, that follows the river from Appleton almost to Almonte. It has thrived for as long as anyone can remember and was well adapted to the normal ebb and flow of the river with high water levels during the spring flood, and low levels for an extended period in the summer. The trees tolerated the floods nicely as long as the roots had a period to dry out and breathe during the summer low water. The first evidence of dying trees in the wetland began to appear about 2006 and regrettably, the die- off continues to this day. The MVCA has attributed the rise in water levels as due, in part, to the flashboards at the Enerdu weir. (See Appendix 1)

 3. Swimming and Recreation

 The Enerdu Expansion document states that there is no swimming in the affected area, yet the riverbed immediately below the current flash boards are a popular community recreation site for walking, sunning and swimming. Indeed the popularity of this wonderful community resource has noticeably increased since the river walk project was completed. The deep water below the train bridge has been a popular diving and swimming location for town youth for generations, which makes this activity a heritage element of Almonte town culture. It is interesting to note that while swimming and jumping into this area of the river are “discouraged”, the activity does not appear to have been legislated as illegal. The beach at the fairgrounds is also impacted by water levels controlled by Enerdu . OEL-HydroSys states that water levels will increase at the beach.

 4. Boating

The report dismisses boating within the affected area. The Mississippi River is the



Motor boat near Thoburn Mill (photo courtesy of Harold McKay)

(See Appendix 2 for more on the history of boating here) 


5. Watercraft Barriers

There is no mention in the Expansion document of the water safety requirements associated with the proposed upgrade. We ask that specific plans for floating water barriers up stream, as well as any fencing and signage, required by statute, be communicated to the Almonte community. The  riparian landowners have expressed concern that the barrier locations may effectively cut their navigable access to Reach 18.

6. ANSI and Provincially Significant Wetlands

The 2011 OEL-HydroSys document claims that there are No Areas of Natural or Scientific Interest or Provincially Significant Wetlands within the affected area. This is completely incorrect as the Appleton Wetlands, affected by any water management in Reach 18, have been so designated. Past and present operating practices of Enerdu have been measured, and the high water levels can be shown to have contributed significantly to the elevated water levels in the Appleton wetland area, as well as at public access points in Almonte and Appleton. The very dry summer of 2012 is, of course, an exception to above compliance water levels within Reach 18.

7. Water Management Plan

The OEL-HydroSys document references a need for an amendment to the Mississippi River Water Management Plan but does not specify the nature of the changes sought. We request clarification and full public consultation with regard to seasonal water levels and compliance ranges, as well as proposed changes to the current water taking permit.

8. Compensation Flows

The OEL-HydroSys document specifies a compensation flow of 1 cubic meter per second. We would like further clarification on this point.

9. Run of the River

The report mentions, but does not detail amendments to the Water Management Plan. Is it the intention of the expanded Enerdu power plant to move from a run of the river generation to peak power flow management, and if so, is the intention to operate within the current compliance range?

10. Compliance range

It appears that Enerdu was granted an unusually liberal compliance and operating range, possibly based on the premise that Enerdu had no flow control structures to operate. With the proposed addition of an adjustable weir, we ask if Enerdu would consider operating under a narrower water level range so as to provide a stable upstream environment. The current compliance range of 117.2 – 117.7 m, (approximately 20 inches) would indicate the river level could change by this amount on a regular basis.

11. Mercury Contamination 

We understand that decades of wool and textile production have deposited significant heavy metals, specifically mercury used in wool felting, in the porous river rock, with elevated concentrations common in areas below rapids and water falls. We request that you share with us your assessment of this environmental risk and your risk management plan for the proposed construction phase to mitigate release of mercury and other contaminants into the river system. The 2011 OEL-HydroSys document makes no mention of this fact.

12. Bird Habitat

Page 21, the section on “Biological Assessments” discusses fish, but not birds. Why is this? There are significant bird migrations, nesting and feeding taking place by various species, and below is a photo of one of a pair of loons seen just above the weir. They have been nesting and breeding here all spring. Moreover, the descriptions of the amount of noise the turbines will cause during operation is inconsistent. Mr. Campbell said it will be inconsequential (April 11, 2012 Almonte Tonwhall meeting), but in the OEL-HydroSys report, the noise is described to loud enough to possibly drive birds from this habitat and require a bylaw amendment as the proposed power plant is adjacent to residential areas.


photo courtesy of Harold McKay

13. Lack of Contact with Riparian Landowners

Riparian landowners along the riverbank beside, above and below the project area have not been properly informed of the changes that will affect them most immediately, nor consulted, nor their interests and prior rights been taken into consideration. This cannot be cited as due consultation. Every single household in a generous catchment area should have been notified and have been invited to participate early in the process.

14. Maps and Schematic Drawings

The 2011 OEL-HydroSys document appears to contain information that is inconsistent with the facts and with representation made by Enerdu.

14a. We refer specifically to Appendix A, Conceptual Engineering Drawings. The “Proposed Layout drawing clearly shows the area in the river to be excavated at the tail race, but there is no indication of riverbed excavation in the area leading to the proposed new powerhouse water intake. Is there a more recent graphic illustration of the proposed layout that includes the areas of the river, in Almonte, to be dredged? We will appreciate receiving more relevant, recent detail of proposed dredging and dam placement than is contained in the June 2011 Project Description document.

14b. Is the sketch, “Almonte Weir” dated 2004 for Canadian Hydro Components a relevant rendering of the plans as they are contemplated for June of 2012?

14c. Sketch No. 3, “Location of the New Weir” is not an accurate indication of the proposed location. The shoreline near the Thoburn channel has been misrepresented. The Thoburn Mill channel is not a dry channel as indicated on this drawing, and has water flowing over it even during the dryer months.

14d. We noted with interest that Mississippi Mills Mayor John Levi and Town Planner Steve Stirling informed us that the latest graphic rendering of the site, recently sent by you to them, indicates an intention to place the new weir on the footprint of the existing weir. However, we remained concerned, as Sketch No. 3 appended to the 2011 Expansion Project description, is inconsistent with this statement. We ask you to confirm this location.

14e. We draw your attention to the aerial photograph, “Figure 2 Site Plan”. The labeling is incomplete with respect to the identification of residential properties that are in the immediate area of the Enerdu GS. We feel that the labeling on this photograph is possibly misleading in terms of the impact the expansion will have on the immediate neighbourhood of private residences.

14f. There are no detailed drawings of the proposed power house, but it appears from the photographic overlay of the site, and according to the sketches of the proposed power plant which include a small figure of a man for scale purposes, that the footprint will be a significant presence the river, and narrow the river considerably (approximately 2/5ths) right in the middle of our town, opposite the Barley Mow pub with its outdoor patio. It is difficult to anticipate the height of the structure, but Enerdu has lead us to believe the new structure will stand at about twenty feet above the water level, and include a floor above the turbine level. This seems an excessive intrusion into the heart of the town to be taken without public consultation and for no public benefit.

As the information in the OEL-HydroSys document is dated June 2011, and conflicting, we request a response to the several points raised herein.

We thank you in advance for your attention to our concerns.

On behalf of the members of the Mississippi Mills Riverkeepers Association,


________________________________,  Bryn Matthews

________________________________,  Mary Rozenberg

________________________________,  Cathy Blake

________________________________,  Mike O’Malley

cc Ministry of Natural Resources, Ministry of the Environment, Ministry of Fisheries and Oceans, Members of the Town Council, Town of Mississippi Mills, and Mississippi Valley Conservation Authority


Appendix 1.  A History of the Water Management Levels on Reach 18

There is a serious discrepancy between historically traditional water levels and those adopted by the MRWMP. The concrete weirs with a top elevation of 117.2 m have been in place for many decades and have set the normal summer water level on this 9 km reach of the river. Intermittently through the period of 1967 to 2004, low flashboards (probably around 6 inches high) were added to the top of the weir to increase the head of the dam. Most of the time they seemed to be poorly maintained, with many missing or leaking boards, and during low flow periods the effective water level was the top of the concrete weir. Unfortunately there appear to be no records of how the flashboards were managed through this period, but the memories of a number of local residents support the above scenario.

The rationale for the current “best management strategy” in the MRWMP has never been adequately explained. It does appear that it was primarily to maximize power output at the Enerdu plant by providing a higher hydraulic head.  In 2004 new higher flashboards (0.4 m and 0.5 m) appeared and the river level stayed high all the way to Appleton throughout the summer low flow period. That same practice has continued in subsequent years.

The Appleton Wetland is part of the Provincially Significant Wetland, designated as ANSI, which follows the river from Appleton almost to Almonte. It has thrived for as long as anyone can remember and was well adapted to the normal ebb and flow of the river ? very high water levels during the spring flood, and quite low levels for an extended period in the summer.

The trees tolerated the floods well as long as the roots had a period to dry out and breathe during the summer low water period. That however changed in 2004 with the higher flashboards, and the trees had no summer respite from high water. The result was that the first evidence of dying trees in the wetland started to appear about 2006, and more have continued to die up to the present time.



Trees dying along the inundated shoreline of the Appleton Wetlands (photo courtesy of Al Seaman)


Appendix 2.  A History of Boating on the Mississippi River near the Project Area

There were “hydroplane” and “cracker Jack” boat races on the Mississippi River in Almonte for years. They would start at the fairgrounds, and go upstream for a bit, and then downstream to the bridge near the Old Town Hall, which is within the 250 m impact zone of the proposed expanded Enerdu GS. Boating in this area of the river continues to this day.


Canoeing near the railway bridge (photo courtesy of Harold McKay)






Canoeing in project area (photo courtesy of Harold McKay





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