Township of North Huron – Bridge Renovation

1. Township of North Huron – Bridge Renovation

2. Purpose - Given the need to remove, repair or replace dam with/without bridge due to state of disrepair to explore options. - To explore the possibility of rebuilding the Howson Dam with capability of hydro electrical generation in an effort to finance repairs. - To explore the power capabilities of the river. - To explore technologies for low head electrical generation to provide options for retrofitting. - To roughly estimate the financial implications. - To explore any grants available. - To determine the approvals required.

3. Existing Condition

4. Existing Condition Liabilities - Risk of falling debris and concrete pieces - Structural failure during flooding conditions causing blockage - the spillway on the west side of the dam is more recent construction and is in good shape and does not need repaired at this time – can be used to house generation equipment

5. Option “A” - Complete Removal Complete Removal of Dam and Bridge Benefits: - most economical - complete dissolution of structural liability - allows unmitigated wildlife migrations – good for native species - reduction in upstream water levels during flooding Cons: - lose scenery - very difficult to ever rebuild in the future - lose pedestrian/vehicle passage - risk of invasive specie migration upstream - lose highest potential for water power - lose oxygenation of water (increased eutrification downstream)

6. Option “B” - Rebuild Dam Only Benefits: - maintains pond levels – esthetic value - removes bridge liability - maintains possibility of hydro electric generation - allows possibility to improve flood control capacity – important due to climate change Cons: - costly - lose pedestrian/vehicular traffic - lose potential revenue from generation

7. Option “C” - Rebuild Dam with Pedestrian Access Benefits: - gives potential to continue river trail without using railroad bridge - all the benefits of option “B” Cons: - more costly than “B” - liability for public access - increased maintenance - already an access at railroad bridge – could build stairs

8. Option “D” - Complete Rebuild Benefits: - provides easy access for pedestrians and vehicles - all benefits of “B” Cons: - very costly - increased liability and maintenance

9. Options “B-D” with Hydro Gen Benefits: - value added project - generates revenue - positive community image - takes advantage of free potential energy – cost is in harnessing - provides legacy for next generation (70 year life expectancy) Cons: - will add approx $500K - $1M regardless of option selected - added liability - operational and maintenance costs

10. Potential Power Power = height of water (head) x volume of water (flow) x efficiency - head is achieved through the height of dam and controls such as operating flood gates, operating generator (using the water) or shutting off generator to store water for controlled generation. - volume of water is strictly dependant on environmental conditions and is not controllable - efficiency is dependant on equipment selected (varies from 40 – 95% efficiency) - limited amount of head and great variation in river flows which makes design more difficult Flow Duration Curve - simply the amount of time in a year that the river flows can be expected to exceed a selected value - used to size the generator and turbine There is a head pond area of approx 117,595 m2 so by managing water, can store 4.5 hours worth of water using 7 m3/sec with 1 m of water to generate during peak hours in minimum river flow periods

11. System Sizing Some operating modes need to be considered such as: - do we want to size small and safely generate continually, - do we want to mid size and generate continuous in wet seasons and manage water levels in dry seasons and generate only during peak rates, - we will need to shut completely off for dry season on average 4.5 months. - a minimum water flow needs to be maintained in the river to sustain aquatic health of the river For calculation purposes,7 cubic meters per second will be considered. We have a potential of 4 m head – 3.5 m will be used for estimate.

12. Estimate of Average Revenue At 7 cms, 3.5 m head and 85% efficiency and calculating we generate 24 hrs per day for flows above 7 cms (105 days), use storage pond to generate part days from 2 to 7 cms at peak rates (84 days) and shut off below 1 cms (176 days) we would generate approximately $138,000 annually.

13. Classic Kaplan Turbine

14. Emerging Tech – Helical Turbine

15. Emerging Tech - Cassette

16. Operational Considerations Environmental - Flood controls – automatic powered sluice gates to let go excess water to prevent upstream flooding - Ice control in winter/frazzle ice - headpond management - maintenance of minimum river flows - minimize disruption of current habitat Maintenance - access - automatic level and time of day generation controls - availability of repair personnel

17. Financial Considerations - scope of project - planning and development costs - approvals - construction - equipment - operational costs - maintenance costs - does equipment selected qualify for innovation grant of 50% - an “out there” idea - do we want to consider building something that can be used as a testing facility? This would be used by developers to test innovative, low flow equipment as there has been very little R&D on situations like ours and there are many similar.

18. Cost Estimate for a Scenario In order to give you and idea of the financial implications we will assume to go ahead with Kaplan portable power unit with grants possibly available and only retrofit spillway, repair existing dam to achieve 3.5 m headpond and remove bridge deck, rebuild dam after year 20. - equipment cost - $890,000 - design and engineering - $50,000 - removal of bridge deck - $150,000 - approvals - $25,000 - electrical connection and switchgear - $75,000 - repairs and installation - $200,000 Total installation costs - $1,400,000

19. Operational Costs - operational cost $30,000 annually - maintenance costs - $10,000 annually (average over 10 years) - borrowing costs ($1.4 M- 25 years at 5.5%) $103,000 annually - total annual cost $140,000

20. Revenue - electricity generated $140,000 annually Net Result - $140,000 - $140,000 =breakeven Influences - cost of installation – major cost is debt service - if paid back in 25 years, there should be 50 years of roi - Maitland river use changed due to landuse – more of a drainage ditch now with flashy flows - would be more feasible if grant available

21. Conclusions/Thoughts - river flows intermittent and unreliable due to loss of base flow - would be more feasible if more head could be achieved (limited) - explore more equipment and retrofit options to possibly find a system installed for under $700k? - increased liability (insurance premiums) - due to long life span, longer financial plan necessary - our generation would have to pay for it – future generation should reap benefits - probably not financially possible given current and future debt load - revenue generated would be equivalent to 25 home taxations - regardless, something needs done with existing dam and bridge - possibility of new technology being piloted here?

22. Where do we go from Here?? - is this a direction we want to head? YES, then - apply for Feed In Tariff to guarantee we can sell electricity - determine installation cost threshhold and explore more cost effective options - $750k debt service would be $55k - consider financing options – NH only, partnerships? Not attractive for investors due to low margins - select consultant to verify numbers, design retrofit - apply for approvals to Natural Resources Canada, Ontario Ministry of Enviroment, Oceans and Fisheries, MVCA, Westario - select equipment - remove bridge deck, repair existing dam, retrofit spillway to accomodate unit - install and operate No, then - decide on bridge status – replace, repair or remove