Episode 10: The flood factor

Show Notes

In the spring of 2017, creeks and rivers and Okanagan Lake all spilled their banks during the worst flooding to hit the region in decades. The City has done a lot to manage spring freshet since then but as temperatures climb and snow melts, it’s a good time to think about flood preparedness. In this episode of Kelowna Talks, Bob is joined by Rod MacLean, our utility planning manager, to talk about freshet, floods and what we learned from 2017.

What is Kelowna Talks?

Welcome to Kelowna Talks, a podcast presented by the City of Kelowna that explores the "why" behind the decisions that shape your city. Tune in for weekly episodes with host, Bob Evans, Partnerships Office Director with the City of Kelowna, as he welcomes guest subject matter experts to explain the processes and decisions that influence the lives of the citizens.

Kelowna Talks - EP10
Rod 0:00
As an engineer, we're always looking quietly at what bad things can happen. The worst cannot happen. We can withstand just about everything, but there are going to be stressful times.

Zoe 0:11
Welcome to Kelowna Talks where we explore the why behind the decisions that shape your city. Together, we open the curtain and dig deep into current issues, plans and policies that come out of City Hall. Thanks for joining us as we talk about Kelowna, and the topics that matter to you.

Bob 0:36
Hi, everyone, I'm Bob Evans, partnership director at the City of Kelowna and host of our Kelowna Talks podcast, I acknowledge that our community is located on the traditional ancestral unceded territory of the Syilx Okanagan people. Well, today we're talking about freshets. That's the fancy name for the spring snow melt that usually occurs between April to July in British Columbia. It's not just about snow, though, there's several variables that determine whether that snow melt turns into flooding downstream and how much snow is in the mountains, temperatures rainfall on and on. Some folks may remember back in May 2017, we saw significant flooding in Kelowna. The highest inflow ever recorded to Okanagan Lake, Mill Creek, spilled its banks, many homes and businesses were flooded. It was crazy, perfect storm, so to speak. Since then, the city has done a lot to prevent that sort of devastating flooding from happening again. We're going to find out a little bit about that today. Welcome Rod McLean, our Utility Planning Manager to our chat today.

Rod 1:35
Good afternoon.

Bob 1:36
Well, Rod, we like to always start this off with just getting to know who you are a little bit and bringing more of a personality not that we need to in your case, but to the listeners to let them know who you are. And when you're not working utilities, what do you like to do for fun?

Rod 1:52
I've been living in Kelowna for about 17 years now. And I started with the city about four years ago. And right after this Freshet business happened in 2017. Basically, I've been an engineer for most of my working life, whether in design or in project management, and always dealing with something water related, started off in agriculture now more into water supply and municipal municipal works. What comes with that is a lot of camping, a lot of fishing. I absolutely love, love fishing. We go as a family, we go and look for as many opportunities like that as we can. And with that, of course, comes the left turn to go see a dam or go see some museum pieces. So we enjoy the traveling part.

Bob 2:43
Yeah, I can relate to that. It's whenever we're traveling with our kids. I'm kind of an architectural nut. So we have to see something of significance in every city. It's like Oh, really? Do we have to do that? How long is this gonna take?

Rod 2:53
That's the way it works.

Bob 2:55
So tell me a bit more about fishing. What's the biggest fish story? How big, what variety, where?

Rod 3:02
The best fishing I've ever done is in west of Lethbridge, actually, and mostly bull trout, and fly fishing. So essentially, the way I like to do it, if we drive up to a point, I find a horseshoe in a creek and walk for four kilometers, take my day and well, finish it off and hopefully have something to eat at the end. Try not meet any bears on the way.

Bob 3:25
That's probably a good idea. Well you're in the right province for that then forr your fishing habit. Could take us back to me 2017. What happens? Was it literally a perfect storm. Are these things you want to remember even?

Rod 3:39
Well, freshets are not made from storm events. They're made from long term water accumulation in some way. So as an engineering consultant to the city, we had been we've been working and looking at different flood options on Mill Creek. And of course, at that time, the things were very dry in 2016. And the snow accumulation during the winter of 2016, and 2017 kind of showed up where there wasn't a lot of worry, in fact, there was worry about filling the lake and province manipulates the lake, they can move water in and out or at least control it in some way. And in this case here, they were anticipating that there was going to be a drought. Well, what happens is there's a lot of, there's a lot of measurement going on in the hills, Okanagan Lake is is over 150 kilometers long. Actually, I might have my numbers wrong there, but it's certainly 90 kilometers long. It's a couple of kilometers, three kilometers wide in some locations. And it has it has a fairly narrow watershed to it. And so whatever falls on there, basically the water is controlled in the lake and the outlet. The province started controlling the outlet in early early 1950s. And basically it's like a big bathtub and it's controlled by the top, not by the bottom, there's no, there's no way to empty the lake, the only way you can do is skim off the top. And that's how they control floods now. And what they did was they allowed a certain amount of water to disappear. But they didn't allow enough through. And that's because they thought that they were meeting they were going to be able to meet their targets of a drought year to make sure that the lake was full enough, unfortunately, from about March 10, for the next three months, it rained either a lot or a little bit every day. And what is rain down here ends up as snow up top. And so for those skiers out there, Big White was wonderful, it was a wonderful ski year and they wanted to extend the year and what have you, because it was the the snow was just so good. But as with any snow event that comes to an end. And of course, the it was a hot May. And immediately that snow started to melt and came down the hill. And there was no way to stop it. And so that's when things started happening. It continued to rain through May. And you could see you could see the water starting to rise and there was nothing they could do. They couldn't open the gates up fast enough to allow water through. It wasn't made to do that. And in the end, the lake continued to rise.

Bob 6:19
Okay, so hate to linger too long on this, but it took weeks and months and millions of dollars to clean up. What what do we learn through that event? As a city that we can now take into forecasting either future initiatives or just even how we treat the waterfront? What, what kind of takeaways do we have?

Rod 6:39
Well, one of the big messages that needs to come out is that Kelowna is built in a floodplain. And in the 2017 storm, we were unfortunate to be flooded by creeks, and then also by the lake itself, the lake was a little bit more unfortunate in that maybe if we had better information earlier in the season, if we knew that it was going to rain for the extra three months that it did that we wouldn't, maybe not be in not much of trouble. So that is what we've been focusing on for the last four or five years now has been how do we get better information at our fingertips and better modeling and better understanding of the flooding? And and what happens.

Bob 7:19
Well, I like your comment that we're built on a floodplain. I think many of us, probably most of us forget that. Or don't even think about that on a daily basis. We love how flat our city is how easily accessible the lake is, you know, all the great attributes of being on a floodplain. But it sometimes rears up its natural course, so to speak, and we pay the price for it. T

Rod 7:40
That's right if you look through the history books, there's history of flooding here. There's history of flooding throughout interior BC and we found that out in 2021.

Bob 7:50
Well, I'm looking at Calgary here but you know, like as another comparable or Winnipeg. A lot of major cities across Canada have similar issues. So we're not alone in that. So it's about management. And we try to manage it as best we can, given the fact that we're dealing with nature and who can really truly predict drought or you know, a month of rain at the same time. So my understanding, my notes tell me the city spent close to a million dollars along mill creek after that event after the flooding event. Can you tell me what that money did? Why did we spend that and what do we get from it.

Rod 8:24
So once a flood event starts happening, the planning is out the door, this all becomes operational, and we do things like unplug culverts, we have staff on standby. We have a number of bridges and floodplains that require close monitoring, we look at things like tiger dams are basically temporary diking systems along to try and keep water contained within the creeks when where possible. We also have to do quick fixes whenever something does fail or something erodes and breaks like a bridge or, or watercourse. We're also looking at the outlets of the creek. And we're also trying to where possible, looking at the residential areas that might be getting hit as well and doing some temporary works in there. So it's not hard to spend a million dollars, right. It's not hard to spend $10 million, right, if you're not careful.

Bob 9:15
Right? Okay. And what are those little things, the sausage, orange sausage, things we saw on the beaches, that's part of that mitigation as well.

Rod 9:22
Yeah, those are part of booms basically. And that's to manage debris. So floating debris that's going along the lake. It can also be used to keep people out of there, similar to the tiger dams that they have along the edges. It's also to keep people out and just manage debris and make sure that things are contained as much as possible.

Bob 9:41
Also, what are some other things that maybe the average person average system doesn't know about? My understanding is that you use sensors in the creeks to monitor either flow or, or height or volume or whatever the metrics are.

Rod 9:54
So for the last 30 to 40 years, there have been what they call manual flow measurement and the feds have done some measurements along a couple of the creeks. But in 2017, we, we stepped it up and we started monitoring, we engage the Okanagan Nation Alliance and a couple of other consultants to improve our hydrometric network and do better flow monitoring. So now we have flow monitoring year round. And we also have better information and better access to, to the past information where we can kind of compare it to previous years, we're not trying to model a future we're trying to compare it. Okay, what does this event look like to something that's happened in the past?

Bob 10:37
Okay, as you're talking, I'm thinking to myself, how does it impact your hobby fishing? So this is just maybe a little bit off script for your professional, you know, knowledge perspective, but again, we look at bio systems and the health of the lake from a water quality and environmental perspective. How does it impact the Kokanee in the spawning and creeks and so on? Is it factored into these natural cycles and that's just what happens but it still maintains a healthy environment?

Rod 11:08
Water is water, whether it storm water, wastewater, drinking water, irrigation water, you name it's groundwater, it's, it's all water, essentially. As utility planning manager for the city, we look at water in terms not only of supply but of water quality. And one of the biggest issues with flooding, of course, and stormwater and drainage is water quality, and our impact that the city puts on Okanagan Lake. I always remember and I always remind people, that Okanagan Lake is the source of our drinking water. So whatever we put in has the ability to come back. And so right now we rely very heavily on the size of the lake. And the water quality is so high in the lake right now, add depth, that is our drinking water is good, but we have to monitor that. Right? And we've got things like stormwater, we do put our wastewater effluent we treat it to the highest degree possible, we actually discharge that back into Okanagan lake. And then of course, we have the stormwater and drainage events that happen around, we have salt on roads, goes back in all of these are all factors that go into and they all end up in the creek and then eventually end up in the lake. So we have to keep an eye on all these facts.

Bob 12:23
Okay, that's good to know. So you're you're monitoring all of this, and it's a complete healthy ecosystem is our goal, right? And that's what we have so far. What can the average Joe the average citizen do to protect themselves during during freshet? Sort of hope and a prayer? Or are there things we can do here?

Rod 12:41
Well, I think what we do is we pay attention to the messages that are coming out and we pay attention to the information that we have. I'm an average Joe too just as much as you are, as much as anybody else who looks at the news and looks at the data. But really, if you're in a floodplain, that's the first problem is that you got to protect your house, you got to protect your property in whatever way you can. But you're not always going to be flooded every year. Whenever we're talking about floodplain. We do have risk mapping out there, which kind of identifies what kind of event can impact you. And we do have some of that mapping. And we're getting a lot better with some of the modeling. So these are the this is the kind of information that everybody has, in terms of around your property itself becomes a little bit more operational. The city has sandbags, they have booms around they have they have different tools at their disposal. But basically, we're always targeting something that's greater than a 50 year event or something where we really get concerned.

Bob 13:40
Right. Okay, so you mentioned sandbags, booms, and so on. If something did happen, let's hope it doesn't in the next little while. Is there a resource page on the city website? Like where do people go to find out about this?

Rod 13:55
Yes, we have the Emergency Operations Center kicks in, at this stage here, and this is a group with the Regional District, the city and other and provincial employees, and there becomes the communication level quadruples, right over time, all of a sudden you start hearing things on where to go on the news and such, the city does have its own emergency webpage and has a lot of directions and a lot of frequently asked questions and, and responses to questions like this.

Bob 14:25
Okay, good. Well, so keep your eyes open, ears open. We talk quite a bit on this podcast about the city budget and money and an impact on budget. So it's hard to say what our citizens really think about the impacts of these major climate events on our city budget, we've had fires, we've had storms, we've had flooding, we've had drought, and we made strides on climate change as a city as a province or are we going to keep having budgetary challenges, how are we dealing with that? I know it's a big huge question.

Rod 15:01
There's a couple of questions in there. And a couple of ways of going. The budget side, I'll leave alone at the moment. Essentially, it's, it's what capacity do we have to manage water in the city. And we use, we use things like pipes and sewers and catch basins. That's the drainage component, we call that the minor system, right, and minor system flows. And then we have the natural systems, we have the creeks, we have creeks and lakes and, and larger creeks, let's, let's say, and these are the conveyances into the lake, which then take flows down to the ocean or wherever, wherever it's gonna go. And, and it's in these natural areas where you get habitat, right. And frankly, over the last 30 to 50 years, we really haven't paid enough attention to our natural systems. And we've allowed the city to develop closer and closer and closer to the creek. And this riparian area coupled with the width and the channels and allowing things to grow and such has caused some concern to be able to pass flood flows.

Bob 16:08
Can you tell us what riparian areas I know what it is, but a lot of listeners don't know

Rod 16:12
Riparian areas, essentially, the green around the creek, creek itself will consider of the channel you always see the channel, but the riparian area is actually the area that floods naturally. And it might flood on a on a weekly basis or, or not. But it's also habitat for where fish reside. Fish don't just live in the channel, they actually try and they end up in the grass and in the protection basically and under trees. And so this is all part of the natural ecosystem of the of the lake. If that gets under pressure, then the more water that goes into it, you start seeing changes in it. And it might be things like more sediment, right. And so all it takes is if you have added sediment in a system, you have a little bit of water, it breaks it free, it looks like erosion. But really what it is, is sediment and poor water quality going down the stream. So now we are impacting the fish, and we see that in the numbers of the numbers of fish in the in the creeks. We have work to do, right?

Bob 17:19
Yeah. And the other thing I think about these riparian areas is just the ability to have larger swaths of green open space for absorption. So again, we're not just channeling everything, we're actually having absorption capability in the soil to go into the water tables.

Rod 17:36
That's right. And that's and that's the ability, that's our ability to make the water as clean as possible going into our, to our streams. But back to back to climate change. So climate change is really, that piece in between most of the money and most of the budget that we spend is between the systems. We're not spending money on the creeks. We're not spending money on the pipes and the sewers and stuff. But it's, it's how the water gets from one point to the other. And climate change, we're seeing higher flows. So all of our sewers may be under sized one day, but doesn't really matter. They'll overtop it's a question of where it goes after that has to go somewhere, it has to go somewhere. And a lot of what we call our major systems are things like roads, we design, overland flow routes, we'll get this problem when with housing and development up in the hills, that water has to go somewhere or in channels, or some of the works that we have that lead into the lake, climate change is impacting us there. And then of course, if we infringe too much on the creek and the natural systems, then climate change can hit us there as well.

Bob 17:36
Okay, Rod as a follow up to, to climate change what we can do, you know, I live here, and I'm in the city. And I know there's been quite a bit of work done on Mill Creek. So can you help our listeners understand what historically the city has been doing at Mill Creek and how that has impacted the situation we're referring to?

Rod 19:01
Yeah, so Mill Creek is a key creek that runs through the old downtown historical area of of Kelowna, lots of pictures of it over the last 120 years or so, of all the different impacts. So Mill Creek has always been an issue, the development that's occurred around it over the years has basically tightened it so that it's not easy for water to overflow its banks. There's also been roads driven down the center of it, buildings built inside it, we haven't been really kind to it. And there's also a rail trail that goes right down, right, pretty much down the center of it. And so we've been looking at different ways, especially with climate change upon us. There are diversion structures and infrastructures that was installed by others in the past and as recently as 40 years ago. And what we need to do is we need to look at different options to kind of prevent some of the flood spikes that do occur in the city because there is a diversion. That was built 40 years ago that tide diverted some water over to Mission Creek. And everybody assumes that is what protects the downtown. Well, there's a lot of different factors that go in. So we went after a federal grant back in 2017. And we're successful in 2019, by the end of it to do some major works to improve our flood protection abilities.

Bob 20:25
Good. Well, tell me a little bit more, but just a couple sentences on what was the value of that? And what what did that money buy us?

Rod 20:32
Right, so we got a $22 million grant, which buys us $55 million worth of value. Yeah, that's nice. There was a matching grant kind of thing, and essentially, what we're doing now is we're looking at four sectors to reduce the impacts of any creek flood that happened. So we've established what we think is the new 200 year level, which is kind of the official level that everybody likes to know about. But essentially, we've thrown a lot of really bad scenarios into our modeling and into our design. And we've identified areas downtown where we're going to do some improvements, and we're going to do it in public places. Real time, we are looking, for example, at Parkinson to do some improvements through there. The big project, which is going on right now is changes to the diversion. Basically, we're doubling the capacity of everything there. Okay, and slowing the water down. As with floods going through it right now. It's it's a very unsafe environment for our staff. And then after that, we are looking at some major diversion work along Brandt's Creek as well.

Bob 21:33
Yeah, there's a lot of different elements that feed into climate change. And you're confident that we're in your particular area of responsibility that we're doing the right things?

Rod 21:41
Well, we're starting to do the proper things we need, we need to look at the risk, we need to look at this more as a risk based approach. Infrastructure is at risk all the time. So what we're doing now is we're taking a look at things that might be impacted, things that we care about more, or things that have more value, or more importance to city infrastructure, we're definitely looking and trying to prioritize that as best as we can.

Bob 22:06
And we don't have unlimited funds as a city. And that's where we're gonna, we're gonna direct those funds to have the most impact.

Rod 22:12
That's absolutely the challenge. And so we watch what's happening outside of our community, and we see what impacts they've had. And we try to learn from those occurrences, let's say.

Bob 22:21
Okay, and that's good to know. Well, we're getting close to the end of our time. Rod, I like to ask you this question as well. You're standing on top of Knox Mountain, you're looking around, it's spring. Let's see, it's now it's spring. And you pull out your crystal ball, the rod crystal ball? What are we looking at for spring? 2022? Fresh it? Are we in good shape? What do we have two, from an expectation standpoint in the next month or two? You can refuse to answer that question.

Rod 22:48
But no, no, I always I never refuse a good discussion. As an engineer, we're always looking quietly at what bad things can happen. As a member of the community, there's always positives. The worst cannot happen. We can we can withstand just about everything. But there are going to be stressful times this year. We've taken a look, we're actually very similar, believe it or not to 2017 right now in where the snowfall is and where the rainfall as we always expect, we know from the history that our March's and April's are typically what the challenges now is making sure that we know that it hasn't rained that much. We know that the snow quantities have not risen that much. So we're cautiously optimistic that we're in an average year. You know what those rains happen, and we want that rain to last, 2021 was an extremely dry year.

Bob 23:46
Yes. Yeah, I think we can all attest to that. Well, thank you for your time today. It gives me solace that we have professional engineers like yourself and the rest of your team, looking at these key aspects of our city to ensure that we're all making the best strategies and efforts towards balancing out this this fragile environment that we call water. So thank you for your time today, Rod and I look forward to many stable years ahead of us.

Rod 24:14
We look forward to it as well. Thank you very much.

Zoe 24:19
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