Clean Water Works
CLEVELAND, OHIO: From the Northeast Ohio Regional Sewer District, an in-depth and fun conversation led by Donna Friedman and Mike Uva on any and all topics related to clean water, wastewater treatment, stormwater management, and the people, projects, and programs serving Lake Erie and our local waterways and communities.
Clean Water Works
Warmer, Wetter Weather: Tackling Urban Stormwater Problems
Cities with aging infrastructure face an uphill battle with regard to stormwater management, a challenge underscored by recent calamitous weather events. Sewer District engineer George Remias illustrates how a warming atmosphere acts like a sponge, soaking up more moisture and leading to intense rainfalls.
Given the potential for the weather's damaging impacts on urban centers, we discuss the vital role of monitoring tools in forecasting rain events and planning resiliency projects, and the value of collaboration among agencies to safeguard our communities.
I was thinking about ants earlier this weekend.
Speaker 2:Thinking about ants.
Speaker 1:Yeah, I was walking and I almost stepped on one and I was like, oh boy, can you imagine if you were about to be stepped on all the time? I don't know. Just things that we don't really think about.
Speaker 2:Yeah Well, they don't think about it. Nobody ever thinks about the ants. They have one task, right.
Speaker 3:They just do it.
Speaker 1:Follow the chemical trail Rinse and repeat Digging tunnels and Taking names.
Speaker 3:All right, so is this the podcast? This is it. This is all we need. We got another 50 minutes to fill.
Speaker 2:You are an engineer.
Speaker 3:I am an engineer.
Speaker 2:Specifically, you are the manager of stormwater strategic support in our watershed department. Yes, Watershed programs department. Yes, we should probably introduce you, huh, george Remus.
Speaker 3:George Remus.
Speaker 2:Yes, is that how you pronounce it, remus?
Speaker 3:You can go Remus or Remus. We've got history on both sides which we could talk about some other day.
Speaker 1:I feel like we asked Andrea to pronounce it once. Andrea also works at the sewer district and is also an engineer.
Speaker 2:George's wife.
Speaker 1:George's wife. They pronounce it differently. I swear you guys say your last names differently. We did it on purpose. That's so mean it starts from?
Speaker 3:I guess we'll get into it right. It starts from Youngstown area and our church. There's a big Remus presence in Youngstown. There was different sides that called it remus and remius. It really came down to the the family member, my parents, for my grandfather's side how they he pronounced it versus another person from his family what pronounce it a different way?
Speaker 1:what um ethnicity is it?
Speaker 3:slovak slovak. Okay, so it would be Remiosh if you're coming from Slovakia. Maybe we should just stick with that, and it was like some of them went Remus, others went Remius, and so, depending on who was your grandparent at the time in the same church, remus and Remius, and so I was totally entertained by this as a child.
Speaker 1:So let's talk about the weather. How do you feel when people say that talking about the weather is small talk? Do you get offended?
Speaker 3:Usually someone asks me about the weather. Andrea holds her breath.
Speaker 1:That is so funny Because it's all about careful what you wish for.
Speaker 3:It's like, how much do you really want to talk about the weather?
Speaker 1:So tell me something. Tell me something about the weather.
Speaker 3:Well, I was looking at one of these interesting statistics and this was someone who presented from us. It's someone that we're partnering with, from MIT. They're from the National Center for Atmospheric Research, and they have come to an agreement that the increase in the frequency of heavy precipitation events will be nonlinear with more warming and will be higher for rare events, and they agreed that about 7% of the maximum amount of moisture will be increased for every one degree of Celsius of global warming.
Speaker 1:Can you break that down for me? What does that mean for?
Speaker 3:So there was someone from National Weather Service in Cleveland. He used this great description of this Think of the atmosphere as a sponge. Okay, as a sponge. As a sponge, okay. And so the warmer the climate is, the bigger the sponge is. So the bigger the sponge, the more moisture it can hold. And so if the planet is warming, it's got a bigger sponge. Or if you think about the summertime, it's a bigger sponge. And so if you can start holding more and more moisture, then there's more and more water that's in the atmosphere that you never know how it's going to get squeezed as well. So if there's more water, slash moisture in the atmosphere, a bigger storm could come along and it could be more rainfall over a longer period of time, or it could be a lot of rainfall in a shorter period of time.
Speaker 1:And you said it was 7% for every one degree of Celsius.
Speaker 3:That's right, that the maximum amount could be held. So some of the things that they're predicting as they're looking at it is it could increase by as much as four degrees Celsius, and so that translates into close to 30% increase in maximum amount of precipitation, which becomes a big deal when you start thinking about how we've sized things before. Pipes are not easy to replace and if you assume the certain rainfall amount before now, you're going to say, well, increase it by not only 30% of maximum amount, but that intensity is one of the biggest pieces. How much more of that moisture can get squeezed into a shorter period of time? You can do the most damage around here.
Speaker 2:How does this tie into your work here at the sewer district? What is your job here?
Speaker 3:So one of the primary responsibilities I have is we have what we call these stormwater models. Our stormwater models include this hydrologic model which kind of takes all this rainfall, applies it over a surface. Trying to understand what the rainfall is, how that gets distributed across our service area, then translate that into what are the flood risks is a big part of what I ultimately are looking at here at the district.
Speaker 1:So we hear people say all the time 100-year flood. Can you just, in your own words, give us a breakdown of what that stems from?
Speaker 3:So the 100-year is they kind of switched it over to maybe the probability is the new way they call it the annual exceedance probability and that's the 1% chance of any given year that kind of storm can happen. That's why they kind of turned it into a 100-year storm. Is really that 1% chance in any given year that storm can happen?
Speaker 1:And so for our area, it's 5-ish inches of rain in 24 hours.
Speaker 3:Yeah, about 5.3 inches over 24 hours.
Speaker 1:There's a 1% chance. Currently, with the given model, there's a 1% chance in a year that we'll have a 24-hour period with 5-ish inches of rain.
Speaker 3:Yes, in any given year. Now, that was based on NOAA.
Speaker 1:National Oceanic and Atmospheric.
Speaker 3:Administration Sure.
Speaker 3:It's one of those national weather services. Under that it's part of NOAA Right, so we'll leave it at that. And so they developed something and published it back around 2004, this NOAA Atlas 14, that said all these different storms for all the different regions across the country, and we've been using that information to this day to help size pipes and assess flooding. But the problem with that publication is, as you can tell, it's over 20 years old now and so when you start thinking about a lot of these big storms everyone's kind of reporting about, none of that is factored into their projections.
Speaker 1:Right, so you're saying climate change isn't really factored in?
Speaker 3:Most of the hottest recorded months on record have happened over the last five or so years. So those are those chances for all that moisture to be held up in the big sponge and then squeezed across wherever. And there's been some really bad storms that have happened worldwide. And there's been some really bad storms that have happened worldwide. There's been places where dams have failed and completely devastated certain populations and there's been massive storms. If you cross the country and think about Houston, when they had their big rainfall, it was like 50 inches of rain. And then Carolina, when they had one of their hurricanes, it was over 30 inches of rain. And then Carolina, when they had one of their hurricanes, it was over 30 inches of rain. So I mean you start thinking about going back to our 1% chance of a little over 5 inches and you start seeing 30 inches here and 50 inches there. I mean it's a big deal of when one of those storms happens, just how devastating it can be to the population. Devastating it could be to population.
Speaker 1:And it should be noted that, like for the Cleveland area, the 100 year storm is that 5.3 inches, but it's different depending on what region you're in.
Speaker 2:So you know.
Speaker 1:LA their 100 year storm looks very different. You know it's not 5.3 inches, it's a lot less than that.
Speaker 3:Yeah, florida's is even significantly higher than our 5.3 inches, to put it into perspective, right, because I think Florida it's a lot warmer, right? Then there's a lot of coastal areas where that water can come from. In terms of sources of rainfall, back in 2006, if I remember, we had a near 100-year storm that devastated Cuyahoga River main stem.
Speaker 3:I think that was the closest I've seen to a hundred year storm. I think Lake County maybe is the Grand River where they had a rather significant amount of rainfall as well. I'm trying to remember was it seven inches in 11 hours or 11?
Speaker 3:inches in seven hours it was cars and couches flowing down the river because it just, you know, there's so many unfortunate um locations where you're there's a floodplain. You know that's the area where the water, you know I like to call a stream has three pieces. There's a channel and two floodplains. People think of the channel, forget about the floodplains, until a really big storm when it's supposed to go out and spread out in those areas and there's a lot of homes and businesses that are in those floodplains. That's the part that I think is one of the areas that we're most at risk of. Bigger storms require bigger floodplains and the more you have within that floodplain, that's one of the areas that can certainly be at risk.
Speaker 1:And most of our infrastructure is not built for a 10-year storm, let alone a 100-year storm.
Speaker 3:Yeah, the older communities. A lot of the stormwater management regulations we have today, like sizing pipes to handle a certain storm, putting in stormwater control measures or detention basins whether it's for flood control purposes, water quality volume purposes, these riparian stream setbacks, the FEMA All that stuff didn't happen really until like the 80s in terms of sizing a lot of this stuff. So you think about all the infrastructure you had to build to support a society At that time. That best in technology at the time was combined sewers and we didn't have the kind of storms that we have today when you size that infrastructure. So that's one of the biggest challenges that we have is when you have older infrastructure like combined sewers, particularly if you start thinking about Cleveland and Cincinnati were two of the top 10 cities in the country at that time none of the regulations we have today were really met.
Speaker 3:So the stream back setback ordinance, you know, keep away from the stream because it's going to move. There's the fema floodplain that you're trying to consider is stay away from the deep waters because that's where the water should go. We're talking about outside of the channel, the floodplains. Start thinking about all the detention basins that are required today to handle all that increased impervious area and then thinking about the bigger storms that we have today, none of that was factored into all that infrastructure. So we have, from Ohio's perspective, since our population is very modestly increasing versus some of these other states where it's much more aggressively increasing their infrastructure factors, some of those standards for the new infrastructure, but ours is, because of the older population, the standards that were there before. You know that's part of the burden that we have. Streams were filled in with pipes. You know we call them culverted streams. Here we have a lot of that. There's a lot of structures that are within that 100-year floodplain.
Speaker 2:These older cities are just not prepared because of the lack of standards when they were built.
Speaker 3:Yeah, it's tough to get out of the way of water when you have your society built right where it wants to go.
Speaker 3:We saw some pretty heavy storms last summer of water when you have your society built right where it wants to go. We saw some pretty heavy storms last summer. Yeah, yeah, Unfortunately, I want to say in the very beginning of the year we had what we'd call a drought, yeah, and then it completely flipped on its side. You know where the July and August storms. We had three significant storms I can think of a July 2nd storm, there's a July 20th storm and an August 23rd storm and different parts of the service area got hit from different parts of those storms. Some of those were those really intense storms that hit a small pocket but caused a lot of devastation and one of the unfortunate challenges I think I'm thinking about the one on the west side where we had a near 100-year storm.
Speaker 1:Was that Westlake that got hit really bad?
Speaker 3:Westlake and Brook Park got hit really bad as well, and that led to a lot of flooding. Portions of Brook Park and Cleveland got hit really hard and the shoreway kind of over in the Lakewood area there was a lot of standing water. A lot of cars either had to stop or very slowly wait for it to recede and proceed on the highway. So we've got an interesting capture of that.
Speaker 3:And then there was a lot of railroad underpass flooding that kind of came to our attention, both on the west side and on the east side, depending on the different storm that we got experience and that you know. Those are the ones where they had to have emergency rescue to evacuate people from cars because the water was so deep and dirty and it was there for so long that they actually had to close off the road and then evacuate some people from cars. And those are the kind of concerns that any community would have. And just seeing those storms that we just experienced and the intensity, those are the ones that, with what we're talking about, with warmer temperature, bigger sponge, those intense storms can cause a lot of damage here in the surface area.
Speaker 2:What are some of the tools that you use to keep track of the amount of water and the speed of water in our stream system and our tunnels?
Speaker 3:I know the district as a whole. We've got 30 rain gauges that we manage. We've got 30 rain gauges that we manage and we've contracted with the United States Geological Survey, usgs, for 11 additional rain gauges to support kind of understanding what's happening in our service area. And there's others like Ohio EMA they have. I think they were going to deploy 160 rain gauges across the state and maybe another 100 more in a phase two Emergency management agency. Yes, that's right. And so there's all these different rain gauges.
Speaker 3:I want to say there's over 60, maybe that cover this big span that we're looking at to help understand what is the measured rainfall on the ground. And then you blend that with this radar rainfall data that NOAA slash National Weather Society helps produce and we blend that radar rainfall with the gauge is the heavy rain, where is it coming, where is it going and if there's any areas of interest that we need to be aware of for either notifying people or tracking it from a rainfall perspective. From the monitoring side, you know, just measuring levels, water levels, discharge levels we have, I think, over 140 monitors in the ground, that's a lot.
Speaker 1:Do you look at every single one every day?
Speaker 3:Not every day, but during big storms. I will track them all.
Speaker 1:Day diary the Cuyahoga River gauge at River Mile 16.
Speaker 2:That's it. Are they in the stream? Are they in the water?
Speaker 3:Yeah, I mean they're alongside the bank and they're measuring the water elevation. We have all those monitors along the Cuyahoga River in our service area to help figure out how high the water gets.
Speaker 1:Why is that important?
Speaker 3:Some of it is just to give people notification of the water. It's reached a certain flood stage, so water is getting out of the channel into the flood plane, getting some advanced notifications of when that happens so people can take action. Sometimes rows simply need to be closed because the water has gotten so high. The other part that we're doing with them is they're developing these flood inundation maps based upon different stages, because obviously the floodplain of the Cuyahoga River is very wide, and so understanding who could be impacted from those different stages will give us a list of people we might need to notify.
Speaker 1:Okay, some of this is paid for through the Regional Stormwater Management Program through the sewer district. But you definitely mentioned a lot of different partnerships there between the USGS Ohio Emergency Management Agency the National Weather Service.
Speaker 3:National Weather Service, yeah, yeah, I mean the district is definitely paying for a number of these monitors, but they're not the only ones that are paying for this. You know some of these were there before the stormwater program was formed right, because the Cuyahoga River at Independence obviously Cuyahoga River very big river there's a lot of potential impacts for if the river gets out of its banks and starts flooding other places. But we are definitely one of the partners trying to understand where it floods and who to notify and how to respond and then how to mitigate any of those activities. Moving forward, national Weather Service is a great partner. The USGS has been a great partner.
Speaker 3:Some of our local communities obviously we're partnering with across the board of you know where do you have flooding? How can we help? Do we need to put in a monitor? Would you like to get some notifications when we think heavy rainfall is in your neck of the woods? Or put a monitor there to give you notification when, say, a basin might reach its emergency spillway or if there's flooding taking place on a road? So it's been quite helpful. And then these research universities that we've been working with over the past few years has been really helpful as well.
Speaker 1:So we use a lot of this data to inform our current construction design and construction projects for our stormwater projects. So our basin designs, our stream restorations, trying to understand how we can better mitigate flooding. But we also share that data across the board and I think that that's a really big deal because we are collecting money from our residents, but the more we can work with others who are also trying to create benefit in the area, probably the better that money is spent.
Speaker 3:Yeah, I think anything we produce here at the district we're always happy to share with whomever, and people come to us and say, hey, I'm going to do some work in a stream of our interest. Hey, do you have a stormwater model? Maybe we can use.
Speaker 3:And so here's the model. Feel free to use it, and if you're going to do any updates to it, can you share it with us so we can have a more updated version of the model for the next project? What do you like about the work? I think there's been real problems that have translated into that. We've either made them go away for the storms that we've experienced or at least lessen their burden. Right, you know, public safety Ressa was talking about those river underpass floodings those are kind of one of the things that we're trying to better understand and help those real problems get addressed. So there's no emergency rescues, if we can get to right, you know, and sometimes it's just trying to solve problems that someone woke up today and they didn't realize that their road will be flooded or their basement will be backed up.
Speaker 3:So I think being able to help get to the answer, get to the what is the right project, and then where do we want to do projects first, is, I think, important for us, because we talked about that Older community, a lot of population, a lot of infrastructure. Where do we invest to help resolve those issues that were not thought of back in the day because they didn't realize they were coming. Who would have thought that the temperature was going to rise 100 years ago? When they're like, how do I build to support Cleveland? And he's in a rigged suburb? So I think it's the realization that these are real problems. The science is saying they're only going to get worse. And you know we've got this program that is really meant to help where to put what and who to help with it. So I think that's there's always a reason to get out of bed and work on it.
Speaker 2:That's nice. How did you get into this, such a?
Speaker 1:civil servant. I love it.
Speaker 2:When you were embarking on a career as an engineer? What led you to?
Speaker 3:So I was in the civil engineering track, got a civil engineering degree out of it, and when there is a whole bunch of different ways you can go with civil engineering right. There's geotechnical and structural, to think about a couple of them. To me it was always the water resources that I was most interested in. Going back to my Youngstown days, I can always remember there was one or two storms during the summer that the road in front of us would back up and, depending on how big of a storm, sometimes there would be a car that would travel through and get stuck. So there's always those kinds of projects like well, when is that going to go away? And it never did.
Speaker 3:Sometimes it was rainfall that would get into our basement from surface runoff coming from backyards that were just. We were at the low point and the water would find its way over there. So I think, just being mindful of the discomfort of flooding, whether it's through a basement, or the flooding of watching cars get stalled, you know it just when I started thinking about things that I've always found interesting and then wanted to be able to solve, it was one of those tracks that I just seemed to have a natural interest for, very mathy, which just so happens to be something I like to do and seem to be pretty good at. So it's just all these data points, this whole data-driven business decisions that we're trying to apply with what rains, where and how does that translate into flooding, and how to call that a risk and prioritize that Do you have any general recommendations for municipalities in this area?
Speaker 3:There's lots of things we can say. I think one of the ones that I hope is these a term that was passed on to us a year ago, almost to this day about these microbursts. Right, they call them rain bombs. Those are real problems and I think it's tough to accommodate how to handle a rain bomb. Right, they showed an example A rain bomb. A rain bomb, it's a convective storm, one of those where it has enough rainfall in a short period that it can just open up. It's like the sky opens up and all that sponge that I was talking about. That's when they squeeze the sponge and it all falls down.
Speaker 1:We had one in Parma a few years ago.
Speaker 3:Yeah.
Speaker 1:It was like a 200 year, but it was only 15 minutes. July 5th 2019. 30 minutes, it was insane.
Speaker 3:Yeah, I call that the equivalent of the laser beam of destruction. Yeah, you know, that was just a lot of flooding in a short area, but anything that got impacted by that was significant. But, going back to the question, you know where are your weak points, right, where do you have the most significant flooding in the shortest, with the smallest storm? We call it over here the probable annual risk score, so understand where is your most frequent probable annual risk or the most likely area to flood. Just be mindful of that so you can track from a rainfall perspective or from a monitoring perspective. You know where to go. Sometimes a big storm rolls through, and things that we've been learning over time is where to go and, equally important, where not to go because you have limited resources. So make sure you're focused on those areas and then those are the ones that you need to focus your projects on, ones that you need to focus your projects on. My general recommendation to anyone going back to that whole society most of our infrastructure was built before today's regulations is where can you retroactively meet today's standards? Sometimes includes property acquisition. Sometimes it includes, you know, retrofitting existing basins or adding basins. Sometimes it's, you know, providing enough space for where the water wants to go, because the water will tell you where it wants to go. One of the things we've learned is you know being mindful of where it wants to go and essentially get out of the way wherever you can. One of the things we're also learning about is you know, from a surface perspective, you know some areas we have, have a pretty have, have a fair amount of topography, and so when you start thinking about sizing streets and you put in what we call catch basins right, collect the water on the side of the street, intercept it and put it into the storm sewer pipe, the steeper the road and the more intense storm, the less percent of that storm is actually going to get captured in those catch basins. So if it misses where it was supposed to go, it keeps racing down to the next one. You can just start seeing the cascading point where it gets to the low point and unfortunately those railroad underpasses are some of those low points that you can see. The more area that can race down to that underpasses are some of those low points that you can see, the more area that can race down to that underpass and then those catch basins that were there can quickly get overwhelmed by the volume and you start thinking about the stuff that gets collected because it's not clean water can start clogging those catch basins, then you've got the double whammy of all that stuff. So that's the beginning for me, to start looking at sites that are low points.
Speaker 3:Where can you offset some of that runoff? Is there a place for doing green infrastructure? It's not like you want to put in a bigger pipe everywhere, because now you're going to push the problem downstream. So where can you hold the water back? Where can you absorb it into the ground? And then when can you release it downstream the ground? And then when can you release it downstream so you're reducing that flood risk wherever possible?
Speaker 3:Anywhere you can take that impervious area and manage it, on site or before it gets below ground, the better. You know, from the stormwater side they kind of defer to the below ground system as the minor system For the very reason it's just a small pipe in many regards and the part that's on the surface is the major system. So the more you can hold it back, I think the better off, because those pipes were not meant to handle the storms of today. They're not meant to handle the storms of tomorrow if they can't handle the storms of today. So where can you hold the water back so it can handle that?
Speaker 3:I think finding those opportunities is going to be key to our future and you know part of our program is to uh, you know, encourage green infrastructure. Um, it doesn't have to be green per se, but you know anything you can do to hold the water on site, on the surface, because once it gets into the system, whether it's the pipe or the stream, that general knowledge of get out of the way is, I think, something to be mindful of. George Remus or Remius.
Speaker 1:Or Remius.
Speaker 2:Thanks for joining us today.
Speaker 1:I'm Clayton Waterworks.
Speaker 2:A podcast.
Speaker 1:About.
Speaker 2:Water.
