BC Hydro: Puntledge River Operations Update

May 17, 2018

Via Stephen Watson, Stakeholder Engagement Advisor at BC Hydro:

May 17, 2018 Update: Generator out of service - higher flows at Nymph Falls and Stotan falls

"Our Puntledge River generating station went out of service early Wednesday morning. We are investigating the cause and anticipate the powerhouse may be out of service until the end of next week. To maintain downstream river flows for fish habitat, and to control the upstream reservoir level and the snowmelt inflows into the reservoir, we are bypassing flows from powerhouse and releasing that extra water below the Puntledge River diversion dam. This is a public safety advisory of higher flows at Barber’s Hole, Nymph Falls and Stotan Falls sections of the river and to please stay out of that area of the river through May 27.

The current water release down the Stotan Falls section of the river is about 24 m3/s, or about four times the base flow. The rest of the Puntledge River is at typical flow levels.

On Friday night we will release up to 90 m3/s from Comox dam through the system to control the reservoir level and provide ideal flows for kayakers.

Then on Monday the river flow will be back to the typical flow, with the exception of the Nymph Falls and Stotan Falls section of the river which will remain high and up to 40 m3/s. 

In the evening of May 25, we will increase flows again from the dam for the annual Puntledge River Paddle Festival on May 26-27.

BC Hydro asks the public to stay away from the Puntledge River on May 19-20 and May 26-27, and that people stay away from the 5 km stretch of the river from the Puntledge River diversion dam to the powerhouse, including Nymph and Stotan falls, from now through May 27."

May 15, 2018:  Puntledge River operations update - another kayak flow event this weekend

"The snowmelt continues at a fairly high rate so BC Hydro, in working with the kayaking community and to control the reservoir level, will provide another weekend of ideal kayaking conditions on the Puntledge River.

The Comox Lake reservoir dropped down to 134.58 metres from last weekend’s kayak flow release, and is currently at 134.71 metres. The reservoir level will continue to rise as the weekend approaches. BC Hydro’s goal is to keep the reservoir from free-spilling over the dam at 135.3 metres.

We will increase the water discharge from Comox dam to up to 90 m3/s on Friday night. Experienced kayakers will be able to take advantage of the water abundance on Saturday and Sunday.

For public safety we ask the public to stay away from the Puntledge River on Saturday and Sunday. Danger safety signage will be in place by Friday evening.

The Puntledge River may be at normal flow rates on Thursday and Friday, and during the week days next week, for swimmers and river users.

BC Hydro will provide the annual Puntledge River Paddle Festival flows, up to 110 m3/s, on May 26-27.

And a reminder that our annual Puntledge River siren system test is today and tomorrow."


Previously May 10, 2018: BC Hydro: Puntledge River operations update - kayak flows this weekend

"The rate of snowmelt is significant and the rate of rise in the Comox Lake reservoir level continues at about 10 cm per day. The reservoir is now at 134.8 metres and is half a metre from beginning to free-spill over the Comox dam. We plan to keep the reservoir below 135.3 metres.

The average water inflow from the rain and snowmelt into the reservoir yesterday was 77 m3/s, and we are forecasting the daily inflow to be about 60 m3/s over the next five days.

To control the reservoir we will be doubling the water discharge from the dam to about 80 m3/s on Friday night. We are targeting a flow rate that controls the reservoir level and also benefits a water use interest – kayakers. Experienced kayakers will be able to take advantage of the water abundance, and given the current flow rate from the Browns River of about 11 m3/s, they will see about 65 m3/s at the Puntledge/Browns confluence, and over 90 m3/s in the river below the powerhouse.  

For public safety we ask the public to stay away from the Puntledge River on Saturday and Sunday. Danger safety signage will be in place by Friday evening."


Previously: May 8, 2018

"Water supply forecast

BC Hydro has a water supply forecast that’s developed each year for the February to September period. This considers the year's precipitation and snowpack, as well as historical inflows over the same period. The forecast provides a guide to our operations in how we may need to conserve water supplies as we go through the summer and into the early fall.

The February to September forecast is updated each month, though the May updated forecast provides us with the best reading of what the water abundance may be like this summer. That’s mainly because snowpack normally peaks around the end of April.

The overall February to September forecast is for 85% of normal. However, the residual forecast or the water supply from May to September is 91%. February and March were very dry, though the snowpack is about normal, so this reflects that nuance.

We have been running the 24 megawatt (MW) generating station at about 17 MW and recently increased to full capacity given the current water abundance in the system from snowmelt, which is in full force. We also slightly increased the flow below the diversion dam down Nymph Falls and Stotan Falls. The reservoir level is currently at 134.6 metres and rising at about 10 cm per day. A full reservoir is about 135.3 metres. The range of reservoir operations is generally from 131 m to 135.3 metres. BC Hydro will manage downstream flows as needed to manage the water storage through the summer for fish, domestic  water supply and power generation.

Puntledge River system siren system test

Public safety is very important to BC Hydro and we communicate as much as we can when river flows may not be normal. Flood risk management, kayak flows and summer fish migration flow requirements are common reasons for needing to spill water downstream, but those events are planned operational changes where BC Hydro can provide notice. There are other situations where river flows can adjust quickly and be unplanned either from the powerhouse or the two dams. To test and ensure our siren system is working should an unplanned event take pace, we will be doing actual water flow test in the Puntledge River on May 16.

Whether planned or unplanned, quick river flow adjustments can be a public safety hazard, so the BC Hydro warning sirens placed along the river from the Comox Dam to Puntledge Park should initiate during these flows tests. Permanent river safety signage is in place, but the siren system provides the real-time flow event in advising people to get out of the river.

We will be manually testing the siren system on May 15, from 8:00 am to 4:00 pm, prior to the actual flow tests on May 16. On the 16th, the first process involves slowly ramping down the generating station from 24 megawatts to a shutdown, and shifting the water over to the diversion stretch of the river, and increasing that flow from about 6 m3/s to about 20 m3/s. This flow redirection is to keep fish habitat fully covered and limit any potential impacts to fish from the test. After 8:00 am, there will be a quick pulse release from the Comox dam to increase the river flow by an additional 20 m3/s. This flow should initiate the siren at the dam and as the water surcharge moves downstream, with the other sirens initiating in sequence. For the last part of the testing, the flow out of the generating station will be increased quite rapidly to test the siren just downstream of the station.

Unlike other system tests when the sirens are initiated individually, this test is to determine that they work as anticipated during an actual river flow change. We have made numerous changes to the system, including a new siren sound that’s a slow whooping sound that’s becoming the standard sound for all hydroelectric utilities across Canada. The strobe lights, angled down or up the river corridor, are to initiate and are intended for night time warnings. The water low test is done once a year.

The normal discharge from the Comox Dam is about 32 m3/s. At various times on May 16 the flow release will drop down to 20 m3/s and hit a peak of about 40 m3/s. 

The public is advised that on May 15 and 16 you will hear the siren sounds and to not enter the Puntledge River until after 4:00 pm. Temporary caution and danger safety signage will placed along the river from Comox Dam to Condensory Bridge. Staff will also be along the river to monitor the warning system.

This is also an educational exercise to remind people that there are hydroelectric facilities on the river and unplanned water flow rises can take place. Enjoy the Puntledge River this summer and please be reminded of general water and river safety considerations, and this information can be found at http://www.redcross.ca/what-we-do/swimming-and-water-safety/swimming-boating-and-water-safety-tips. With the warmer weather, people will begin to gravitate to water to cool off and enjoy the summer. About 500 people have been counted throughout the Puntledge River system at one time.

The Puntledge River hydroelectric system includes the Comox Dam, which impounds the Comox Lake Reservoir, where the water released travels 3.7 kilometres down to the Puntledge River Diversion Dam. From there, a minimum fish habitat flow is provided down the river and the majority of water is directed down a 5 kilometre penstock to the generating station, where the water is then discharged back into the river. River flow hydraulics and under-surface currents can be dangerous. Only 15 centimetres of fast flowing water is enough to knock a person off their feet.

Puntledge River Paddle Festival

About 150 white-water enthusiasts will take on the Puntledge River on May 26-27. The event is a condition of BC Hydro’s water license with the Comptroller of Water Rights, as agreed to by BC Hydro’s community-based water use planning consultative committee. The kayak releases target a river flow at the Puntledge River/Browns River confluence of 65 m3/s and then 85 m3/s on Saturday, and 110 m3/s on Sunday. The event it well timed to the snowmelt period and good water abundance.

BC Hydro advises the public to stay away from the Puntledge River from May 26-27. Only people registered in the V.I. Whitewater Paddling Society event should be on the river. Public safety signage will be placed along the river system.

The V.I. Whitewater Paddling Society and Fisheries and Oceans Canada have coordinated the event timing, as they do each year, in tandem with the Puntledge River Hatchery’s chinook salmon smolt release for a better success rate of the out-migrating fish reaching the ocean.

Summer Chinook migration and spawning flows

This is the time of year for the summer Chinook salmon migration flows to enable them to move up the 5 kilometre stretch of the Puntledge River from the generating station to the Puntledge River diversion dam, and ultimately into the Comox Lake reservoir. There will be five, two-day releases, starting June 12 and 13 and then taking place each Tuesday and Wednesday until July 12.

From June 12 through to July 12, on each Tuesday and Wednesday, a public safety caution advisory is in place for the Barber’s Hole, Nymph Falls and Stotan Falls stretch of the river as flows will be more than double the normal. River flows at this location will go from about 6 m3/s to up to 17 m3/s. Temporary safety signage will also be in place."