WEB EDITOR'S NOTE: The first of two letters from Peter Cronin regarding the need to restore the St. John River by looking at the present impact of the Mactaquac Dam was previously shared in an ASF Webworks. Below is a second part.
CLICK HERE FOR PART 1
Peter Cronin wishes to acknowledge the assistance and input of John Bagnall in preparing these letters.
Mactaquac Commentary by the New Brunswick Salmon Council – Part 2
In our first installment of this commentary, the NB Salmon Council addressed arguments presented by Mr. Larry Jewett, President of the Friends of Mactaquac Lake, for maintaining the Mactaquac Dam and headpond. Now for our arguments for removing the dam.
We think that is a valid question as to whether Mactaquac’s power is now even needed. Many industrial enterprises such as mines and pulp mills have closed down in the province, and power for these operations is no longer needed. If Mactaquac’s power is needed, the proposed Grand Falls expansion project, which would have no effect on sea-run fish, would be more environmentally acceptable than a restored Mactaquac Generating Station (GS). The Grand Falls project was envisioned to export power to New England, but we have since learned that the rapidly-increasing supply of solar and wind power capacity there means that New England may not need Grand Falls’ power (TJ, Nov. 10, 2015). The Grand Falls alternative could replace Mactaquac’s lost power for domestic consumption and provide “Black Start” capabilities.
Mr. Jewett brings up Mactaquac’s value as a storage facility for generating power on demand. This is true. But again as explained in the first part of this commentary, Mactaquac is a poor hydropower site, and will need a huge investment to rehabilitate. Why doesn’t NB Power, like utilities in New England, encourage private solar and wind power generation, and invest the money saved on Mactaquac in one or more closed-loop pumped-storage facilities? A river site is not needed for pumped storage, only make-up water to replace evaporation. Pumped-storage sites are chosen based on their available generating head. In pumped storage, a reservoir is established at the rim of the receiving basin. Dual-direction turbines are installed in the pits. When the sun shines, excess power is used to spin the turbines to pump water from the pit into the reservoir. When the power is needed water is released through the turbines to generate power. Pumped-storage technology is greater than 80% efficient (Energy Storage Assoc., 2016) for a single pass. This is only one suggestion for storage. Improved battery technology is also on the horizon.
Finally, the environmental costs of the Mactaquac development are not being fully considered. For example, there is massive mortality incurred by Atlantic salmon smolts and spawned-out adults during their downstream passage through the upper St. John River. Fisheries and Oceans Canada (DFO) studies in the 1990s demonstrated that salmon smolts travelling from the Tobique River returned from the ocean as adults at a rate approximately 50% lower than those originating from downstream of the head-of-tide at Mactaquac. This was interpreted as a ~50% in-river mortality rate for headwater St. John River (Tobique) salmon smolts. A follow-up study determined that this rate is even greater than this now. For comparison, the mortality rate for smolts travelling from the Miramichi River headwaters is in the order of 10%. The additional mortality among the upper St. John River smolts is strongly suspected, and in some cases proven to be the result of power generation or infrastructure associated with it.
The St. John River Atlantic salmon are a component of the Outer Bay of Fundy (OBoF) salmon population, which is currently being considered for listing as “Endangered” under the Canadian Species at Risk Act (SARA). As part of the SARA listing process, a Recovery Potential Assessment (RPA) is performed by a committee of DFO’s Science Branch with advice from various interest groups. This is a direct quote from the RPA for the outer Bay of Fundy salmon population (DFO, 2014): “Based on available information, hydro-power generation dams (hydro dams) are considered to be the most limiting threat to OBoF salmon population persistence.” St. John River hydropower production may be renewable, but it is not “green”.
Recent Rivers’ Institute work has also determined that salmon smolts, during their downstream migration, are delayed on average for two weeks in the Mactaquac headpond, where they are subjected to abnormally elevated rates of predation. Because of reversing current directions in the headpond, these smolts spend much of their time swimming upstream, away from their ocean destination. OBoF salmon smolts are in a race to reach the Labrador Sea before warm water engulfs the Scotian Shelf and the thermal window for salmon migration closes. A two-week delay in the headpond in a warming climate is a big deal.
Just to be clear as to where our organization stands, the NB Salmon Council is in favour of a restored St. John River through the removal of the Mactaquac Dam and headpond. We have no vested interests other than our concern for the Atlantic salmon and the groups that use them for recreational, food, social or ceremonial purposes. The preference for river restoration also applies when Option 4, which should really be termed Option 1A, is included. River restoration is the only option for the Mactaquac facilities that produces a restored “sense of amenities” (Jewett, TJ, May 5, 2016).
DFO. 2014. Recovery Potential Assessment for Outer Bay of Fundy Atlantic Salmon. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2014/021.
Energy Storage Assosciation. 2016. http://energystorage.org/energy-storage/technologies/pumped-hydroelectric-storage .
References for other statements made in this commentary are available on request.
Peter Cronin, President, NB Salmon Council