WEBVTT 00:00:16.000 --> 00:00:22.000 [M.C.] You guys have the great fortune today to hear from Dr. Fouad Jaber 00:00:22.000 --> 00:00:25.000 with Texas A&M AgriLife Extension Service. 00:00:25.000 --> 00:00:30.000 Fouad is one of the state's most renowned engineers and educators 00:00:30.000 --> 00:00:34.000 on green stormwater infrastructure 00:00:34.000 --> 00:00:37.000 --many of you know it as low impact development. 00:00:37.000 --> 00:00:41.000 Dr. Jaber is an Associate Professor in Integrated Water Resources Management 00:00:41.000 --> 00:00:47.000 an Extension Specialist with the Extension Service located in Dallas. 00:00:47.000 --> 00:00:50.000 Dr. Jaber received his PhD in Ag 00:00:50.000 --> 00:00:52.000 --Agriculture and Biological Engineering-- 00:00:52.000 --> 00:00:54.000 from Purdue University, 00:00:54.000 --> 00:00:58.000 with an emphasis on Natural and Environmental Resources Engineering. 00:00:58.000 --> 00:01:05.000 I love the fact that when we were reading Denis' bio, 00:01:05.000 --> 00:01:07.000 Doctor Jaber's bio, these these engineers 00:01:07.000 --> 00:01:12.000 that have that education and experience and understanding of these natural processes, 00:01:12.000 --> 00:01:15.500 these are the guys that we need out here helping with these projects. 00:01:15.500 --> 00:01:18.000 People that understand how it can all work together. 00:01:18.000 --> 00:01:26.000 Dr. Jaber has published more than 24 refereed journal articles 00:01:26.000 --> 00:01:29.000 and more than 100 conference receiving papers 00:01:29.000 --> 00:01:32.000 in addition to extension publications and government reports. 00:01:32.000 --> 00:01:36.000 He is a Registered Professional Engineer in the State of Texas 00:01:36.000 --> 00:01:43.000 and has been dealing with Nonpoint Source Pollution management since 2002 00:01:43.000 --> 00:01:48.000 with funding exceeding $2,000,000 to his research. 00:01:48.000 --> 00:01:50.000 So let's give a warm welcome to Dr. Jaber. 00:01:50.000 --> 00:01:56.000 [Clapping] 00:01:56.000 --> 00:02:01.000 [Dr. Fouad Jaber] That's good information. I provide it, of course. 00:02:01.000 --> 00:02:04.000 Well, thank you for for having me here. 00:02:04.000 --> 00:02:08.000 I came from Dallas, so I'm very grateful for the invitation and the hospitality. 00:02:08.000 --> 00:02:15.000 They drop into your room and I step here --I've never been to this building before-- so it's my first time. 00:02:15.000 --> 00:02:19.000 As I said, I'm an associate professor with Texas A&M University, 00:02:19.000 --> 00:02:23.000 Texas A&M AgriLife Extension. 00:02:23.000 --> 00:02:28.000 Who had a question about the extension? [Inaudible Audience Member] Yes, you can send for examples for $25. 00:02:28.000 --> 00:02:34.000 Just talk to your county agent, and put your soil in a bag, 00:02:34.000 --> 00:02:38.000 fill the form online, put in a $25 check, and send it, and they'll send it. 00:02:38.000 --> 00:02:42.000 If you want more information then you can pay up to $100 00:02:42.000 --> 00:02:44.000 and get information that, probably you want me. [Audience Laughter] 00:02:45.000 --> 00:02:51.000 And I do come from Dallas, but I only eat vitamins and antihistamines, 00:02:51.000 --> 00:02:56.000 so I'm not polluting your water here, in any case, 00:02:56.000 --> 00:03:01.000 I am from A&M, but I think my information is valid --seriously. 00:03:01.000 --> 00:03:06.000 We've we've heard a lot about green stormwater infrastructure. 00:03:06.000 --> 00:03:09.000 But since I'm the professor, I'm going to give you the background here. 00:03:09.000 --> 00:03:11.000 Why do we need green stormwater infrastructure? 00:03:11.000 --> 00:03:15.000 Storm is of the natural environment; Water is not a material. 00:03:15.000 --> 00:03:18.000 Why is stormwater a problem? 00:03:18.000 --> 00:03:26.000 It's a problem because humans alter the surface of the earth. 00:03:26.000 --> 00:03:29.000 That's the problem. The problem is not the stormwater, actually. 00:03:29.000 --> 00:03:33.000 It's just the the the way humans have dealt with it. 00:03:33.000 --> 00:03:37.000 Here is a fast comparison of a natural area 00:03:37.000 --> 00:03:42.000 I think it's the one acre in the world left undisturbed --this right here. 00:03:42.000 --> 00:03:48.000 and this is a typical quarter acre of land with a house and a yard 00:03:48.000 --> 00:03:52.000 and it shows the difference in terms of water volume here. 00:03:52.000 --> 00:03:56.000 When it rains here, the trees capture a lot of the water. 00:03:56.000 --> 00:03:59.000 Some of that water evaporates directly from the trees, 00:03:59.000 --> 00:04:03.000 so it doesn't actually even make it to the ground. 00:04:03.000 --> 00:04:07.000 Whatever makes it to the ground, it goes as through-fall to the ground. 00:04:07.000 --> 00:04:11.000 And then, what happens when it hits the natural area? 00:04:11.000 --> 00:04:15.000 It starts infiltrating and water starts going into the ground 00:04:15.000 --> 00:04:17.000 until either the soil is saturated 00:04:17.000 --> 00:04:21.000 or it's actually accumulating at a speed that's too fast for the soil, 00:04:21.000 --> 00:04:24.000 so it exceeds infiltration, and that's when we get runoff. 00:04:24.000 --> 00:04:27.000 Runoff as it moves in natural areas, 00:04:27.000 --> 00:04:32.000 it's hindered by rocks, topography, vegetation, root systems, trees 00:04:32.000 --> 00:04:35.000 --and so as it slows down, more and more of it infiltrates, 00:04:35.000 --> 00:04:38.000 and the majority of the water goes down. 00:04:38.000 --> 00:04:44.000 A very small portion of the total rainfall makes it to the water body over the surface. 00:04:44.000 --> 00:04:47.000 The majority of that goes into the ground. 00:04:47.000 --> 00:04:49.000 That divides into two sections: 00:04:49.000 --> 00:04:52.000 One goes all the way down to the groundwater, 00:04:52.000 --> 00:05:01.000 and that's mostly in high soils that are coarse like sand or loam 00:05:01.000 --> 00:05:05.000 In clay soils, some of the water goes to the groundwater, 00:05:05.000 --> 00:05:09.000 mostly through cracks due to dry soils. 00:05:09.000 --> 00:05:15.000 The majority of the water actually still travels horizontally in the topsoil. 00:05:15.000 --> 00:05:17.000 Some of it is caught in the coarse, 00:05:17.000 --> 00:05:20.000 but whatever makes it to the water body travels in the top soil. 00:05:20.000 --> 00:05:23.000 The benefits of that --there's two main benefits: 00:05:23.000 --> 00:05:27.000 Soils that have water in them, 00:05:27.000 --> 00:05:31.500 traveling, they have a maximum speed that cannot be exceeded 00:05:31.500 --> 00:05:33.000 and that's hydraulic conductivity. 00:05:33.000 --> 00:05:38.000 You can take the soil, test it --it tells you what the speed of water can be in that soil 00:05:38.000 --> 00:05:40.000 and that's the maximum, 00:05:40.000 --> 00:05:45.000 and that in clay --it's very, very slow-- it's probably 100,000 times slower 00:05:45.000 --> 00:05:47.000 than what would flow over the ground. 00:05:47.000 --> 00:05:51.000 In sands it's probably 100 to 1000 times slower, 00:05:51.000 --> 00:05:53.000 but it will travel through the soil. 00:05:53.000 --> 00:06:00.000 That means that the rain that fell today will just go slowly to the water body 00:06:00.000 --> 00:06:02.000 over the next three ... four ... five weeks 00:06:02.000 --> 00:06:07.000 rather than flowing overland in a very fast period. 00:06:07.000 --> 00:06:11.000 The second benefit of water being in the top soil and moving through soil 00:06:11.000 --> 00:06:13.000 is that soil acts like a filter. 00:06:13.000 --> 00:06:15.000 Sand filters are actually a practice. 00:06:15.000 --> 00:06:24.000 So a lot of the pollutants, actually the chemicals, that come from natural areas and pesticides 00:06:24.000 --> 00:06:26.000 can be divided into two groups: 00:06:26.000 --> 00:06:31.000 One type that binds to soil particles and gets immobilized in the soil, 00:06:31.000 --> 00:06:35.000 and the other is soluble like salt and sugar, and it flows with the water. 00:06:35.000 --> 00:06:39.000 When you're forcing water to flow in that topsoil, 00:06:39.000 --> 00:06:42.000 the soluble ones are absorbed again 00:06:42.000 --> 00:06:45.000 or broken down by microbes or absorbed again by plants, 00:06:45.000 --> 00:06:47.500 and the ones that get immobilized, 00:06:47.500 --> 00:06:51.000 they actually get captured on the soil particles. 00:06:51.000 --> 00:06:54.000 There's a chemical bond happening and they stay there, 00:06:54.000 --> 00:06:58.000 so that water that flows here is usually clearer in natural systems. 00:06:58.000 --> 00:07:04.000 But here come humans, they cut the trees, reducing the first defense line, if you want, 00:07:04.000 --> 00:07:07.000 one ... two ... or three are left 00:07:07.000 --> 00:07:10.000 and then they use their big bulldozers to to build this house. 00:07:10.000 --> 00:07:13.000 So they compact the soil as much as they can here. 00:07:13.000 --> 00:07:22.000 Then come back and buy 2 inches of topsoil, and put sod that they mow at least twice a week, 00:07:22.000 --> 00:07:25.000 so that the root system is equal to the height of your grass. 00:07:25.000 --> 00:07:30.000 So you have a root system that's this big compared to the very deep root system here. 00:07:30.000 --> 00:07:36.000 So not only is the water that falls on the impervious surfaces going to become runoff, 00:07:36.000 --> 00:07:40.000 Actually a portion of the water that falls on your lawn 00:07:40.000 --> 00:07:44.000 will also produce more runoff than these natural areas. 00:07:44.000 --> 00:07:48.500 Therefore, the water is going to be much faster flowing as runoff 00:07:48.500 --> 00:07:50.000 and it's going to be much dirtier, 00:07:50.000 --> 00:07:53.000 not only because it's not getting treated by the soil, 00:07:53.000 --> 00:07:59.000 but also because we are creating new types of pollutants like hydrocarbons on the road 00:07:59.000 --> 00:08:03.000 --heavy metals-- all these are picked up by the runoff 00:08:03.000 --> 00:08:05.000 and taken to the river. 00:08:05.000 --> 00:08:13.000 What you have is soil particles that move with that runoff toward the water bodies, 00:08:13.000 --> 00:08:15.000 and what's the problem? 00:08:15.000 --> 00:08:19.000 Again, sediment soil is a natural material. 00:08:19.000 --> 00:08:21.000 What's the problem if it goes with the runoff? 00:08:21.000 --> 00:08:26.000 The problem is that these soils used to be agricultural soils 00:08:26.000 --> 00:08:30.000 and through the years have been actually accumulating chemicals 00:08:30.000 --> 00:08:33.000 and pesticides that have been sprayed. 00:08:33.000 --> 00:08:36.000 We've just mentioned that pollutants are of two types, 00:08:36.000 --> 00:08:39.000 some get bound to soil particles, others are soluble, 00:08:39.000 --> 00:08:41.000 The ones that are bound soil particles, 00:08:41.000 --> 00:08:45.000 When we dig up a former agricultural land for construction 00:08:45.000 --> 00:08:48.000 and allow sediments to flow with runoff to go to the river, 00:08:48.000 --> 00:08:50.000 you're actually putting in the water 00:08:50.000 --> 00:08:54.000 pesticides that your great-grandfather had probably sprayed 00:08:54.000 --> 00:08:57.000 and we call those legacy pollutants. 00:08:57.000 --> 00:08:59.000 There's a pollutant called Chlordane, 00:08:59.000 --> 00:09:04.000 a pesticide that peaked in the Trinity River in 2008. 00:09:04.000 --> 00:09:07.000 It was banned in 1981. 00:09:07.000 --> 00:09:12.000 The highest ever recorded level of Chlordane in the Trinity River in downtown Dallas, 00:09:12.000 --> 00:09:18.000 which exceeded normal safe levels was in 2008. 00:09:18.000 --> 00:09:23.000 Why? Because it binds to soil particles. It's a sediment-bound pesticide, 00:09:23.000 --> 00:09:27.000 and the boom of construction from '80 to that period 00:09:27.000 --> 00:09:29.000 allowed that increase, and it peaked in 2008. 00:09:29.000 --> 00:09:31.000 Then it dropped back naturally 00:09:31.000 --> 00:09:38.000 because 2008 coincided with 1981 when that the use of that pesticide was the highest. 00:09:38.000 --> 00:09:45.000 Hydrocarbons: Every time it rains, if you actually run and go look at shallow water flowing 00:09:45.000 --> 00:09:48.000 -- whether it's a parking lots as run off or in small creeks -- 00:09:48.000 --> 00:09:51.000 there is this rainbow color, 00:09:51.000 --> 00:09:55.000 this film of oil that floats on top, 00:09:55.000 --> 00:09:58.000 showing that there's actually hydrocarbons going in. 00:09:58.000 --> 00:10:01.000 Even the amount of water is a big problem. 00:10:01.000 --> 00:10:08.000 Why is it a problem? Because it actually messes with the balance of nature. 00:10:08.000 --> 00:10:14.000 So rivers form based on 1000 years of weather data. 00:10:14.000 --> 00:10:19.000 They form and stabilize based on how water comes to them 00:10:19.000 --> 00:10:25.000 and so the general ball-shaped part where we think of as the channel 00:10:25.000 --> 00:10:32.000 forms to carry the flow that comes from the rainfall that happens every one to two years. 00:10:32.000 --> 00:10:36.000 That flow is based on -- most rivers in the world -- 00:10:36.000 --> 00:10:40.000 they've seen that that channel forms naturally to carry that flow. 00:10:40.000 --> 00:10:43.000 Why? It's because it's a low flow that's non-erosive. 00:10:43.000 --> 00:10:49.000 The bigger flows -- actually as the river was forming 10 million years ago -- 00:10:49.000 --> 00:10:54.000 These bigger flows, they actually eroded the edges of that channel 00:10:54.000 --> 00:10:56.000 until there's a floodplain that forms. 00:10:56.000 --> 00:11:01.000 So now the flow that comes from the two-year storm flows in the channel, 00:11:01.000 --> 00:11:05.000 -- the bigger flows, they actually have to spread on a wider space -- 00:11:05.000 --> 00:11:07.000 and they slow down as a result, 00:11:07.000 --> 00:11:09.000 and therefore you don't have erosion. 00:11:09.000 --> 00:11:10.500 That is a stable system. 00:11:10.500 --> 00:11:14.000 Low flows are in the channel, bigger flows are in the bigger channel. 00:11:14.000 --> 00:11:17.000 That includes what we call the floodplain of the river, 00:11:17.000 --> 00:11:19.000 and it's different than the FEMA floodplain, by the way. 00:11:19.000 --> 00:11:26.000 When we urbanize, we convert the pervious land to impervious. 00:11:26.000 --> 00:11:33.000 So now for the one-year event, we're getting way more water than the river is expecting. 00:11:33.000 --> 00:11:37.000 So that starts causing erosion in the stream; It deepens, it widens. 00:11:37.000 --> 00:11:43.000 Then we block the floodplain by constructing in the floodplain, 00:11:43.000 --> 00:11:46.000 so not only now, there's no space for that water to go, 00:11:46.000 --> 00:11:51.000 but also, you are raising that level of the flood plain 00:11:51.000 --> 00:11:55.000 and risking more flooding as a result. 00:11:55.000 --> 00:12:00.000 Water-quality-wise, nutrients -- specifically nitrogen, phosphorus -- 00:12:00.000 --> 00:12:04.000 even if, actually, they do not exceed the maximum contaminant level in the river, 00:12:04.000 --> 00:12:08.000 in most places in Texas at least, that water flows 00:12:08.000 --> 00:12:13.000 and it is stopped at one of the man-made reservoirs that we have. 00:12:13.000 --> 00:12:18.000 There it accumulates. At some point, the concentration of nitrogen 00:12:18.000 --> 00:12:21.000 -- or nitrate specifically, or a phosphorus -- 00:12:21.000 --> 00:12:27.000 can exceed a threshold that can cause algae growth overnight sometimes, 00:12:27.000 --> 00:12:29.000 or over two, three, four days. 00:12:29.000 --> 00:12:34.000 When you have algae growths, algae has a very short life span, 00:12:34.000 --> 00:12:39.000 and as they die off they actually use the oxygen in the water. 00:12:39.000 --> 00:12:41.000 So you start using your dissolved oxygen, 00:12:41.000 --> 00:12:45.000 your water starts smelling, and you start getting fish kills. 00:12:45.000 --> 00:12:49.000 This is Lake Granbury southwest of Dallas. 00:12:49.000 --> 00:12:52.000 They have two to three fish kills a year 00:12:52.000 --> 00:12:55.000 --and that's not unique to that lake. 00:12:55.000 --> 00:12:58.000 Most lakes have that problem in Texas. 00:12:58.000 --> 00:12:59.500 So what's the solution? 00:12:59.500 --> 00:13:04.000 The actual solution is to stop building, moving back to caves, 00:13:04.000 --> 00:13:08.000 and enjoying our [drowned out by audience laughter] but that no one's accepting that. 00:13:08.000 --> 00:13:11.000 Actually, I can't publish that information. 00:13:11.000 --> 00:13:15.000 So, low-impact development is the concept that came, 00:13:15.000 --> 00:13:21.000 meaning we can develop, or we can integrate practices in our development, 00:13:21.000 --> 00:13:27.000 that would make the water quality and quantity leaving our property 00:13:27.000 --> 00:13:33.000 equivalent to what would have left if we hadn't built at that point. 00:13:33.000 --> 00:13:37.000 With time the "low-impact development" term has changed. 00:13:37.000 --> 00:13:40.000 Some people challenged it, some people now use it as the concept 00:13:40.000 --> 00:13:46.000 that you can do development that would have no impact on stormwater, 00:13:46.000 --> 00:13:51.000 but the practices themselves are called green stormwater infrastructure. 00:13:51.000 --> 00:13:55.000 -- at least that's the term the EPA has adopted at this point. 00:13:55.000 --> 00:14:00.000 What are these? They're usually Rain Gardens, or a statement green roof, and rainwater harvesting. 00:14:00.000 --> 00:14:02.000 These are the main four categories. 00:14:02.000 --> 00:14:06.000 There are others. If you Google them, there's probably 15 or 20 others, 00:14:06.000 --> 00:14:10.000 but they're all really a version or a different form of one of these four. 00:14:10.000 --> 00:14:15.000 There's actually a fifth one that I'm going to talk about at the end, 00:14:15.000 --> 00:14:17.000 which is actually small constructed Wetlands, 00:14:17.000 --> 00:14:21.000 but let's talk about each one of those. 00:14:21.000 --> 00:14:26.000 Rain Gardens. They're another name for Bioretention. 00:14:26.000 --> 00:14:31.000 There's a little bit of confusion out there even in the engineering community 00:14:31.000 --> 00:14:33.000 of what is Bioretention, what's a Rain Garden. 00:14:33.000 --> 00:14:38.000 In my understanding it's the same thing, 00:14:38.000 --> 00:14:44.000 but some people like to use "Rain Garden" 00:14:44.000 --> 00:14:46.000 for something that's easy to build 00:14:46.000 --> 00:14:48.000 that doesn't involve too much engineering, 00:14:48.000 --> 00:14:52.000 and "Bioretention" for one that involves engineering, 00:14:52.000 --> 00:14:56.000 but scientifically they're both biologically active systems that retain water, 00:14:56.000 --> 00:15:02.000 and the reason they call theirs a garden is because it can double as a landscape feature. 00:15:02.000 --> 00:15:07.000 So this is a design -- I call it the "Home Rain Garden", 00:15:07.000 --> 00:15:09.000 some people call that a "Ring Garden". 00:15:09.000 --> 00:15:11.000 There's a specific design for it, 00:15:11.000 --> 00:15:17.000 but it involves digging a small hole that's 8 inches --at the most-- deep, 00:15:17.000 --> 00:15:20.000 Usually it's more like 6 or 4 inches. 00:15:20.000 --> 00:15:23.000 You put moss on top of it, You plant it with native plants, 00:15:23.000 --> 00:15:27.000 and you put it where runoff is leaving. 00:15:27.000 --> 00:15:29.000 Water comes in, fills it up, 00:15:29.000 --> 00:15:31.000 that water interacts with the plants, with the soil, 00:15:31.000 --> 00:15:37.000 and whenever it fills up, it will overflow exactly where that water was going before. 00:15:37.000 --> 00:15:39.000 That doesn't need too much engineering. 00:15:39.000 --> 00:15:43.000 You can actually get a couple of guidelines online. 00:15:43.000 --> 00:15:47.000 There are a few fact sheets -- there's one A&M produced -- 00:15:47.000 --> 00:15:51.000 and it tells you how to size it, how big should it be, how deep should it be, 00:15:51.000 --> 00:15:54.000 Depending on different factors in your house. 00:15:54.000 --> 00:15:59.000 You can hire a couple of teenagers to do the the digging and you're in business. 00:15:59.000 --> 00:16:06.000 The commercial type of Bioretention, you can't hire teenagers to do it. 00:16:06.000 --> 00:16:09.000 You do need to get permits for it, you're going to need heavy machinery, 00:16:09.000 --> 00:16:14.000 and the reason is, it's usually in islands of parking lots or in medians of roads, 00:16:14.000 --> 00:16:18.000 and it does involve digging down, removing native soils, 00:16:18.000 --> 00:16:21.000 replacing them with a high-infiltration soil. 00:16:21.000 --> 00:16:26.000 We usually put perforated pipe in the system, we account for overflow, 00:16:26.000 --> 00:16:29.000 so we have to direct the overflow toward the stormwater system. 00:16:29.000 --> 00:16:37.000 So these are engineered systems, where you can usually get credit from cities for reducing impervious areas. 00:16:37.000 --> 00:16:41.000 This is an example of Bioretention in the median of a road. 00:16:41.000 --> 00:16:46.000 See, the roads are sloped toward the median 00:16:46.000 --> 00:16:48.000 rather than centered in the middle, 00:16:48.000 --> 00:16:56.000 and as the water goes toward the median it will fill it up the area right here, 00:16:56.000 --> 00:16:59.000 and then at the end -- I'm not sure it's clear -- 00:16:59.000 --> 00:17:00.000 there's an overflow structure, 00:17:00.000 --> 00:17:03.000 so whenever the water is ponding at six inches or so, 00:17:03.000 --> 00:17:06.000 it overflows in an outflow structure 00:17:06.000 --> 00:17:11.000 that's probably connected to the stormwater system in that place. 00:17:11.000 --> 00:17:13.000 So this is a Bioretention area. 00:17:13.000 --> 00:17:17.000 I said we dig down around 3-4 feet 00:17:17.000 --> 00:17:20.000 and put a perforated pipe in the middle 00:17:20.000 --> 00:17:26.000 and we have a ponding area, and we can calculate engineering-wise 00:17:26.000 --> 00:17:28.000 -- unlike the home Rain Garden -- 00:17:28.000 --> 00:17:32.000 engineering-wise you can actually calculate the the pore space 00:17:32.000 --> 00:17:35.000 in that Rain Garden plus the ponding area 00:17:35.000 --> 00:17:38.000 and you can calculate the exact amount of water 00:17:38.000 --> 00:17:40.000 that would be stored in that system. 00:17:40.000 --> 00:17:43.000 Therefore, you can use it for actually getting credit 00:17:43.000 --> 00:17:47.000 for reducing a very specific volume of water in your system. 00:17:47.000 --> 00:17:51.000 Now, do these systems work? 00:17:51.000 --> 00:17:53.000 --and the more difficult question is: 00:17:53.000 --> 00:17:58.000 Do they work in the clay areas we have here in the Blackland Prairie? 00:17:58.000 --> 00:18:01.000 I'm not sure it's here, but in Texas in general. 00:18:01.000 --> 00:18:07.000 and so a lot of people actually were doubting, when I joined A&M in 2007. 00:18:07.000 --> 00:18:12.000 There was an article that one of the local large engineering companies 00:18:12.000 --> 00:18:16.000 had published in their newsletter that everybody was sending around, 00:18:16.000 --> 00:18:18.000 saying that theses systems don't work in clay areas 00:18:18.000 --> 00:18:20.000 because we don't have infiltration, 00:18:20.000 --> 00:18:23.000 so how are we going to be putting in infiltration systems? 00:18:23.000 --> 00:18:28.000 So I used that to actually get a grant from TCEQ and test these systems, 00:18:28.000 --> 00:18:31.000 so we built the Rain Garden at the Dallas center 00:18:31.000 --> 00:18:35.000 that collected from a large parking parking area. 00:18:35.000 --> 00:18:43.000 So it was a 2500 sqft Rain Garden that was 4 ft deep, and we measured data over 2 years. 00:18:43.000 --> 00:18:45.000 So here's the rainfall. 00:18:45.000 --> 00:18:50.000 The blue is the water, the volume of water, 00:18:50.000 --> 00:18:53.000 that came into the Rain Garden for each of these storms. 00:18:53.000 --> 00:18:55.000 The red is what came out. 00:18:55.000 --> 00:19:03.000 Overall, 49% of the runoff that left the parking lot never left the property. 00:19:03.000 --> 00:19:05.000 We have forced them to infiltrate. 00:19:05.000 --> 00:19:15.000 The remaining 51% was treated. It mostly flowed out through the perforated pipe. It didn't overflow. 00:19:15.000 --> 00:19:19.000 So it's water that traveled the soil after it went in, 00:19:19.000 --> 00:19:22.000 and left through the perforated pipe. 00:19:22.000 --> 00:19:26.000 So 49% never left, 51% left, 00:19:26.000 --> 00:19:28.000 but it was of a much better quality. 00:19:28.000 --> 00:19:29.500 But how can I prove it? 00:19:29.500 --> 00:19:31.000 We did a lot of studies; We measured several things. 00:19:31.000 --> 00:19:35.000 I'm only showing sediments here because it's the most relevant for parking lots. 00:19:35.000 --> 00:19:40.000 We reduced the sediment load -- the amount of sediments that left. 00:19:40.000 --> 00:19:44.000 We compared just the inflow to the outflow of that Rain Garden. 00:19:44.000 --> 00:19:48.000 90% less sediments were in the outflow 00:19:48.000 --> 00:19:53.000 than were in the inflow to the Rain Garden. 00:19:53.000 --> 00:19:58.000 As you can see here, the mass in milligrams of total suspended solids, 00:19:58.000 --> 00:20:01.000 -- which is basically sediments coming into the Rain Garden 00:20:01.000 --> 00:20:06.000 and the amounts that left the Rain Garden -- in red. 00:20:06.000 --> 00:20:09.000 So, yes, they do work very well. 00:20:09.000 --> 00:20:12.000 50% reduction in runoff. 90% reduction in sediments. 00:20:12.000 --> 00:20:18.000 All nutrients --nitrate, phosphorus-- were reductions above 7%. 00:20:18.000 --> 00:20:23.000 Even E. coli was reduced by 65% from that Rain Garden. 00:20:23.000 --> 00:20:27.000 Here's my Rain Garden collecting from the farm lot, 00:20:27.000 --> 00:20:30.000 and it's still standing. 00:20:30.000 --> 00:20:32.000 This is my car as I was coming here to take the picture. 00:20:32.000 --> 00:20:36.000 That car disappeared and does not exist, but the Rain Garden is still there, 00:20:36.000 --> 00:20:40.000 so it has a long lifetime --longer than a car. 00:20:40.000 --> 00:20:43.500 Porous Pavement. What is Porous Pavement? 00:20:43.500 --> 00:20:49.000 It's basically material that you can use as pavement for parking lots or sidewalks, 00:20:49.000 --> 00:20:53.000 but actually it's made of material that is porous, so it has pores like soil. 00:20:53.000 --> 00:20:57.000 It's strong enough to allow a car to park on it, 00:20:57.000 --> 00:21:00.000 but also and allows infiltration through it. 00:21:00.000 --> 00:21:04.000 There are several types. This is a paver block. 00:21:04.000 --> 00:21:10.000 This is actually at the Dallas center, one we built. These are interlocking paver blocks. 00:21:10.000 --> 00:21:12.000 Basically, they're similar to typical pavers, 00:21:12.000 --> 00:21:17.000 But they have a small tooth, if you want, on the edge, 00:21:17.000 --> 00:21:20.000 so when you put them together there's a minimum space that's open. 00:21:20.000 --> 00:21:22.000 You fill that with pea gravel, 00:21:22.000 --> 00:21:27.000 and when it rains, water goes between the pavers and infiltrates into the ground. 00:21:27.000 --> 00:21:33.000 Porous concrete is basically concrete that doesn't have very fine elements. 00:21:33.000 --> 00:21:38.000 It has other chemicals, as you put it together, it will have pores in it. 00:21:38.000 --> 00:21:40.000 Of course you can smooth it on the top. 00:21:40.000 --> 00:21:42.000 That's why it looks granular, like this. 00:21:42.000 --> 00:21:46.000 Porous asphalt actually looks like regular asphalt because asphalt is not actually smooth 00:21:46.000 --> 00:21:49.000 -- but it's very hard to find, by the way. 00:21:49.000 --> 00:21:53.000 You can also use these systems where you use plastic grids 00:21:53.000 --> 00:21:58.000 that you can plant with sod, or you can put gravel on them, 00:21:58.000 --> 00:22:01.000 and there's also here a Texas-made material 00:22:01.000 --> 00:22:04.000 which is just soil mixed with expanded shale 00:22:04.000 --> 00:22:06.000 that increases the infiltration of the soil, 00:22:06.000 --> 00:22:09.000 and you don't put any plastic anything on it 00:22:09.000 --> 00:22:13.000 and the expanded shale is as strong as rock, 00:22:13.000 --> 00:22:15.000 so it does allow for overflow parking. 00:22:15.000 --> 00:22:18.000 Both of those will be used for overflow parking usually 00:22:18.000 --> 00:22:21.000 because you don't want to be parking on natural grass all the time. 00:22:21.000 --> 00:22:29.000 This is a typical design so you can understand how we deal with some problems. 00:22:29.000 --> 00:22:31.000 So here we have clay soils, 00:22:31.000 --> 00:22:34.000 and since clay soils are very low infiltration, 00:22:34.000 --> 00:22:39.000 we can just put the permeable material on top of the soil. 00:22:39.000 --> 00:22:47.000 Then you would be limited with the volume that you're going to be able to retain 00:22:47.000 --> 00:22:50.000 until that water infiltrates just the pores in the porous material. 00:22:50.000 --> 00:22:55.000 So what we do is we put a gravel reservoir underneath. 00:22:55.000 --> 00:22:58.000 That helps with the stability of the system, 00:22:58.000 --> 00:23:01.000 and at the same time it works as a reservoir. 00:23:01.000 --> 00:23:03.000 As water infiltrates, it accumulates in here, 00:23:03.000 --> 00:23:06.000 and so you can probably hold 00:23:06.000 --> 00:23:13.000 -- if you're only collecting from the middle of the driveway and your parking lot -- 00:23:13.000 --> 00:23:19.000 it can probably hold a five-inch rainfall inside it, and it's pretty stable. 00:23:19.000 --> 00:23:23.000 Again, does it work? We measured the data here. 00:23:23.000 --> 00:23:31.000 These are just different types that we tested at the Dallas center: 00:23:31.000 --> 00:23:33.000 The black was the regular concrete, 00:23:33.000 --> 00:23:35.000 we had the grass pavers in green, 00:23:35.000 --> 00:23:38.000 the interlocking concrete pavers in red, 00:23:38.000 --> 00:23:41.000 and the gravel pavers in blue, 00:23:41.000 --> 00:23:43.000 and orange was porous concrete. 00:23:43.000 --> 00:23:49.500 We measured the flow coming out of each of those and compared it to the regular parking spaces. 00:23:49.500 --> 00:23:51.500 This is what we found: 00:23:51.500 --> 00:23:56.000 We had reduction of around 70-90% in volume, 00:23:56.000 --> 00:24:02.000 so it held 70-90% of the runoff from the property, 00:24:02.000 --> 00:24:05.000 and again for TSS --meaning sediments-- 00:24:05.000 --> 00:24:12.000 we had a reduction of 48-57% in the man-made material, 00:24:12.000 --> 00:24:16.000 and we had an 84% in the grass pavers 00:24:16.000 --> 00:24:19.000 -- simply because there's a soil where the pores are smaller in that system 00:24:19.000 --> 00:24:22.000 and most of it probably settled on top 00:24:22.000 --> 00:24:27.000 and reduced the sediment load leaving the parking spaces. 00:24:27.000 --> 00:24:30.000 Here's what we learned about interlocking concrete pavers. 00:24:30.000 --> 00:24:34.000 As I said, there's a designed space in between the pavers; 00:24:34.000 --> 00:24:38.000 You put pea gravel in there and water infiltrates through them. 00:24:38.000 --> 00:24:42.000 So the third practice I'm going to talk about is green roofs. 00:24:42.000 --> 00:24:45.000 It was mentioned a couple of times here. 00:24:45.000 --> 00:24:49.000 Green roofs are a little bit more complex than the other two. 00:24:49.000 --> 00:24:53.000 because they have to have the increased weight on a structural system. 00:24:53.000 --> 00:24:58.000 So you have to make sure that your building can hold it. 00:24:58.000 --> 00:25:04.000 You probably cannot put it on a single, typical homeowner's house. 00:25:04.000 --> 00:25:08.000 It should be probably on more stable buildings. 00:25:08.000 --> 00:25:10.000 This is the Chicago City Hall. 00:25:10.000 --> 00:25:12.000 This is somewhere in Japan. 00:25:12.000 --> 00:25:15.000 and here are two others from the internet. 00:25:15.000 --> 00:25:19.000 We built a demonstration. 00:25:19.000 --> 00:25:25.000 I couldn't find a building on campus that was able to withstand the extra weight of a green roof. 00:25:25.000 --> 00:25:29.000 So I built my own carport, divided it in four, 00:25:29.000 --> 00:25:37.000 and I put three types of systems that are basically different in soil thickness. 00:25:37.000 --> 00:25:45.000 So this one had 4 inches, this one had 10 inches and this one had 12 inches, and here they are. 00:25:45.000 --> 00:25:50.000 I collected the runoff that comes out of the systems, and this was the control. 00:25:50.000 --> 00:25:52.000 So I didn't put a green roof on this one. 00:25:52.000 --> 00:25:58.000 I compared the results of the three treatments to the control. Here they are: 00:25:58.000 --> 00:26:02.000 This is the control. This is the 12 inches. This is the 10 inches. 00:26:02.000 --> 00:26:07.000 I tested 10 inches and put in a drainage layer. 00:26:07.000 --> 00:26:10.000 On this one I used a commercial system. These you can buy. 00:26:10.000 --> 00:26:16.000 "Google" green roofs. You'll find commercially available systems that will be delivered to you. 00:26:16.000 --> 00:26:19.000 and they have way more than just water in mind. 00:26:19.000 --> 00:26:23.000 They have insulation in mind -- Heat Island Reduction -- 00:26:23.000 --> 00:26:30.000 They have a lot of little things that don't have any effect on water. 00:26:30.000 --> 00:26:33.000 Basically they send you 4 inches of soil 00:26:33.000 --> 00:26:36.000 that's why that's best compared to my 10 and 12 inches 00:26:36.000 --> 00:26:38.000 Here are the results: 00:26:38.000 --> 00:26:45.500 So --surprisingly actually-- the 4 inches reduced by 65% 00:26:45.500 --> 00:26:47.000 and it wasn't proportional to the depth. 00:26:47.000 --> 00:26:56.000 The 12 inches reduced runoff or captured 70-76% of the rainfall, 00:26:56.000 --> 00:27:00.000 as compared to the control, and the 10 inches 75%. 00:27:00.000 --> 00:27:06.000 So basically even 4 inches of soil on the top of a building like this one 00:27:06.000 --> 00:27:13.000 can reduce your runoff by 65% leaving the property. 00:27:13.000 --> 00:27:18.000 Gray Water Harvesting. Again mentioned a lot as a water conservation practice, 00:27:18.000 --> 00:27:21.000 but it actually is also a stormwater management practice 00:27:21.000 --> 00:27:26.000 because you're capturing the runoff coming off your roof when a storm is happening, 00:27:26.000 --> 00:27:28.000 so it doesn't flow out, 00:27:28.000 --> 00:27:34.000 and then later you can apply it at a much lower intensity on your lawn 00:27:34.000 --> 00:27:37.000 and make sure that it infiltrates -- doesn't create runoff -- 00:27:37.000 --> 00:27:41.000 so all that runoff that would have contributed to the general runoff 00:27:41.000 --> 00:27:45.000 now can be used for irrigation, later, on your grass. 00:27:45.000 --> 00:27:48.000 But no one has ever done any studies 00:27:48.000 --> 00:27:54.000 on how much, actually, rainwater harvesting can help with stormwater management. 00:27:54.000 --> 00:27:59.000 So we did a study where we measured, for different types of soil, 00:27:59.000 --> 00:28:05.000 how much can we reduce runoff -- and you can see we reduced it for silty clay. 00:28:05.000 --> 00:28:17.000 We tried different sizes. This 833 liters is around 150 gallons, 00:28:17.000 --> 00:28:19.000 but that's not what I'm advocating. 00:28:19.000 --> 00:28:21.000 This was a 10% model. 00:28:21.000 --> 00:28:26.000 So actually, for a typical home of maybe 1500 square feet, 00:28:26.000 --> 00:28:32.000 this would be equivalent to a 1500 gallon tank. 00:28:32.000 --> 00:28:37.000 So a 1500 gallon tank collecting from a 1500 square foot area 00:28:37.000 --> 00:28:39.000 watering a 2000 square foot lawn 00:28:39.000 --> 00:28:48.000 will reduce runoff in silty clay soil by 30% and in sandy soils by up to 50%. 00:28:48.000 --> 00:28:51.000 Since we had the study going, we wanted to check 00:28:51.000 --> 00:28:56.000 how much savings we can get from irrigation 00:28:56.000 --> 00:28:59.000 -- how much less city water we would use. 00:28:59.000 --> 00:29:07.000 Again, this is compared to someone who irrigates twice a week. 00:29:07.000 --> 00:29:12.000 Basically, this is based on my neighbor's scheduling system. 00:29:12.000 --> 00:29:19.000 He's retired and he loves his lawn and he watered whenever he could. 00:29:19.000 --> 00:29:24.000 When I designed that experiment in 2009 we didn't have restrictions in the Dallas area 00:29:24.000 --> 00:29:27.000 so that guy seriously watered every day in the summer, 00:29:27.000 --> 00:29:31.000 twice in spring and in the fall, 00:29:31.000 --> 00:29:33.000 and once a week in the winter. 00:29:33.000 --> 00:29:39.000 He still does that, but he's limited to two days a week irrigation now, at the most, 00:29:39.000 --> 00:29:44.000 So I used that schedule and compared it with and without Green Water Harvesting, 00:29:44.000 --> 00:29:50.000 and for our place's soil, I found that you can reduce water need by 40% 00:29:50.000 --> 00:29:56.000 if you're using a 1500 gallon tank in the system. 00:29:56.000 --> 00:29:58.000 I actually did more studies, where I tried to see 00:29:58.000 --> 00:30:05.000 what would happen if you actually watered according to irrigation recommendations 00:30:05.000 --> 00:30:09.000 using the evaporation-recommended method. 00:30:09.000 --> 00:30:13.000 If you don't know about that, check it out on the Texas A&M website -- 00:30:13.000 --> 00:30:18.000 TexasET.tamu.edu 00:30:18.000 --> 00:30:22.000 -- and it will tell you how you can actually schedule your irrigation. 00:30:22.000 --> 00:30:29.000 If you combine these two methods you can reduce water use by 90% --just using that. 00:30:29.000 --> 00:30:33.000 The last trend I'm gonna talk about is Wetlands. 00:30:33.000 --> 00:30:39.000 Wetlands are a natural phenomena that you can find on coastal areas 00:30:39.000 --> 00:30:41.000 and even inland in some places, 00:30:41.000 --> 00:30:45.000 but they have been disappearing due to urbanization. 00:30:45.000 --> 00:30:50.000 The concept, actually, is perfect for stormwater management. 00:30:50.000 --> 00:30:52.000 So here comes the constructed Wetland system, 00:30:52.000 --> 00:30:57.000 which is a little bit different in water holding times and plants 00:30:57.000 --> 00:31:00.000 than a natural Wetland. 00:31:00.000 --> 00:31:04.000 But actually it can work exactly like green infrastructure. 00:31:04.000 --> 00:31:10.000 Basically what it does is, as water goes in, 00:31:10.000 --> 00:31:15.000 it has sedimentation, it captures all the sediments, 00:31:15.000 --> 00:31:18.000 it filtrates, it absorbs the chemicals, 00:31:18.000 --> 00:31:22.000 there's microbial activity that helps with denitrification and plant uptake. 00:31:22.000 --> 00:31:25.000 This is Exploration Green. 00:31:25.000 --> 00:31:32.000 This is a golf course in Houston that is being converted into a large detention area 00:31:32.000 --> 00:31:37.000 and they hired me to actually design Wetland edges. 00:31:37.000 --> 00:31:43.000 So here from the trail to the water, we've done this as a Wetland, 00:31:43.000 --> 00:31:48.000 and so now whenever it rains water fills up the water hole 00:31:48.000 --> 00:31:50.000 very close to the trail right here, 00:31:50.000 --> 00:31:53.000 and it has to interact with Wetland plants, 00:31:53.000 --> 00:31:55.000 and then it's controlled by the outlet here 00:31:55.000 --> 00:32:00.000 that will drain that area, slowly, over the next 96 hours. 00:32:00.000 --> 00:32:06.000 So we increase the time of interaction of the water with the Wetland plants 00:32:06.000 --> 00:32:08.000 and as a result we get more treatment. 00:32:08.000 --> 00:32:10.000 This one here is MD Anderson. 00:32:10.000 --> 00:32:15.000 I designed a Wetland for them inside their detention pond. 00:32:15.000 --> 00:32:21.000 So their detention pond is this ugly pit that stands with mowed grass all year long 00:32:21.000 --> 00:32:25.000 and doesn't do anything until a big storm comes and fills it out 00:32:25.000 --> 00:32:27.000 and it just slows down the water coming out, 00:32:27.000 --> 00:32:29.000 so all it does is really reduces it. 00:32:29.000 --> 00:32:34.000 We went there and put a Wetland in the bottom of the detention pond. 00:32:34.000 --> 00:32:37.000 So now for the small events -- for the inch and two inch events -- 00:32:37.000 --> 00:32:40.000 we get treatment as a result, 00:32:40.000 --> 00:32:43.000 and it still works as a detention pond for a hundred-year event, 00:32:43.000 --> 00:32:46.000 and it's been working great. They like it. 00:32:46.000 --> 00:32:51.000 We don't have, unfortunately, a lot of data for it, because no one funded me. 00:32:51.000 --> 00:32:56.000 Again, if there's anyone who has money and is interested in how Wetlands perform, give me a call. 00:32:56.000 --> 00:32:58.000 But this is what we do. 00:32:58.000 --> 00:33:00.000 We basically take a detention pond, 00:33:00.000 --> 00:33:05.000 we design something like a meandering river, but with zero slope. 00:33:05.000 --> 00:33:08.000 A Wetland needs to fill up like a bathtub, 00:33:08.000 --> 00:33:12.000 so water comes in one end, and it fills up the whole system as a bathtub. 00:33:12.000 --> 00:33:16.000 This is probably 6 inches deep, the light blue. 00:33:16.000 --> 00:33:20.000 The dark blue is 3-4 feet deep, 00:33:20.000 --> 00:33:23.000 and this is why in dry times it keeps some wetness 00:33:23.000 --> 00:33:26.000 to keep the biological system surviving. 00:33:26.000 --> 00:33:30.000 The different animals that need water will always have water in these blue areas. 00:33:30.000 --> 00:33:39.000 The light blue is the area that fills up and then drains down slowly over the next 96 hours. 00:33:39.000 --> 00:33:44.000 The green area is the part of the detention pond that will fill up 00:33:44.000 --> 00:33:46.000 if you get a bigger storm than a one-inch. 00:33:46.000 --> 00:33:52.000 So, it's an easy design. I don't have measurement data. 00:33:52.000 --> 00:33:55.000 Again, send me a text if you want to pay me, 00:33:55.000 --> 00:33:58.000 but this is from the literature 00:33:58.000 --> 00:34:04.000 and it shows a reduction of all these pollutants -- it varies a lot -- 00:34:04.000 --> 00:34:06.000 but we have a 78% reduction in sediments, 00:34:06.000 --> 00:34:10.000 50% in heavy metals of different types, etc. 00:34:10.000 --> 00:34:17.000 So, these are measurements we did in the field, but do these work at large scales too? 00:34:17.000 --> 00:34:20.500 So, a graduate student came in and said they wanted to do modeling. 00:34:20.500 --> 00:34:22.000 I'm like OK, very good. 00:34:22.000 --> 00:34:27.000 So let's see if these systems --taking data from the field data that I just presented-- 00:34:27.000 --> 00:34:29.000 do have an impact at larger scales. 00:34:29.000 --> 00:34:35.000 So the first study we did, we compared urban density on water quality. 00:34:35.000 --> 00:34:38.000 We had high density, meaning an area that looks like a downtown, 00:34:38.000 --> 00:34:50.000 we had medium density, that is basically a 1/4 acre single home area, 00:34:50.000 --> 00:34:53.000 and then we had medium density conservation, 00:34:53.000 --> 00:34:59.000 which is basically more like townhomes with more open areas in the middle. 00:34:59.000 --> 00:35:05.000 So we ran the model to see what happens without any green infrastructure, 00:35:05.000 --> 00:35:08.000 what happens comparing these systems 00:35:08.000 --> 00:35:14.000 and so here in black you can see what happens without green infrastructure. 00:35:14.000 --> 00:35:20.000 The high density system had the lowest among the three in volume 00:35:20.000 --> 00:35:23.000 because we concentrated --this is for the same number of people-- 00:35:23.000 --> 00:35:28.000 we concentrated the people in 15 buildings and left everything else green, 00:35:28.000 --> 00:35:32.000 so as a result we had much less runoff. 00:35:32.000 --> 00:35:35.000 A lot of it infiltrated before it reached the river, 00:35:35.000 --> 00:35:39.000 compared to when you build single homes that fill up the whole area. 00:35:39.000 --> 00:35:45.000 It was actually 100 mm -- a quarter less from that system. 00:35:45.000 --> 00:35:49.000 Water quality: Nitrate followed the same pattern. 00:35:49.000 --> 00:35:52.000 It was like 1/4 less nitrate coming out 00:35:52.000 --> 00:35:54.000 because nitrate is soluble, so it follows the water pattern. 00:35:54.000 --> 00:35:58.000 Phosphorus on the other hand, was more or less similar in the three systems 00:35:58.000 --> 00:36:02.000 because it's actually soil-bound, 00:36:02.000 --> 00:36:06.000 and so even the green areas still were contributing soil particles. 00:36:06.000 --> 00:36:10.000 Then we put green infrastructures in the system and looked at the results, 00:36:10.000 --> 00:36:15.000 and actually, green infrastructure made the single homes nearly equal 00:36:15.000 --> 00:36:19.000 so it was better than the high density alone 00:36:19.000 --> 00:36:25.000 and it was nearly equal to the high density with the green infrastructure. Same thing with nitrate. 00:36:25.000 --> 00:36:31.000 In phosphorus it actually made the medium density system better than the high density system. 00:36:31.000 --> 00:36:34.000 So green infrastructure makes all these density systems equal. 00:36:34.000 --> 00:36:39.000 The last thing: This is a watershed in Austin. It's called Blunn Creek. 00:36:39.000 --> 00:36:44.000 They asked us to model it and check what would the infrastructure do to the river there. 00:36:44.000 --> 00:36:47.000 Again, we compared the shear stress 00:36:47.000 --> 00:36:50.000 -- which is the erosion-causing force in rivers -- 00:36:50.000 --> 00:36:55.000 when you have green infrastructure in all of the watershed 00:36:55.000 --> 00:36:58.000 compared to now: green infrastructure in the detention pond. 00:36:58.000 --> 00:37:00.000 That light blue is what happens 00:37:00.000 --> 00:37:04.000 when you put Rain Gardens everywhere in the watershed 00:37:04.000 --> 00:37:05.000 compared to what's happening now. 00:37:05.000 --> 00:37:11.000 So it's reduces erosion nearly to zero. Peak flow also is reduced as a result. 00:37:11.000 --> 00:37:15.000 TCEQ, Texas AgriLife Research, Texas Sea Grant, City of League City 00:37:15.000 --> 00:37:20.000 -- all these people paid me to have this data to tell you. 00:37:20.000 --> 00:37:25.000 This is me. If you are on Facebook, "like" our page. 00:37:25.000 --> 00:37:29.000 It's called AgriLife EcoEng, which stands for Ecological Engineering, 00:37:29.000 --> 00:37:31.000 which is what my program is called. 00:37:31.000 --> 00:37:33.000 ... and, end. 00:37:33.000 --> 00:37:35.000 [Audience Applause]