BrownPelican_Vortex_Young_John_AustinTX_8December2023_Reel4182.mp4

John Young [00:00:01] Down in the Pharr district in Cameron County on State Highway 48, there are two bridges down there, that when the roadway was first built in the '30s and '40s, the road was built up and basically cut off water flow from the Rio Grande into what was known as the Bahia Grande Wetland Complex. And it dried that up for 60, 70 years.

John Young [00:00:35] And I think it was late '90s, early 2000s, when Fish and Wildlife Service and others decided to undertake and try to restore water flow to the Bahia Grande Wetland Complex.

John Young [00:00:47] And they approached TXDOT at the time, asked if TXDOT would raise these two locations, raise the road level, and put bridges in so that Fish and Wildlife Service and others could dredge a channel and return water flow and tidal flow to the Bahia Grande Wetland Complex.

John Young [00:01:07] And so, TXDOT accommodated that, and one of the largest wetland restoration projects ever undertaken was able to move forth.

John Young [00:01:18] Well it was probably, I don't know, a number of years ago, but there started to become reports that during winter storm events, brown pelicans were falling out of the sky when they would fly over State Highway 48, specifically when they would fly over one of these two bridges.

John Young [00:01:38] And so, when TXDOT heard about that (and I think I had just started), ... they looked at what can we do here? And our first thought was to borrow from Florida, where we added Pelican Poles, right? Because the pelicans are flying over the roadway just about ten, twelve feet in the air. So we got these Pelican Poles, put those on the bridges to see if we could get the pelicans to fly higher, thinking if they started to fly higher, they'd be able to make it over the road.

John Young [00:02:07] And that helped. We stopped getting direct collisions between delivery trucks and semi-trucks and pelicans.

John Young [00:02:16] But it didn't really fully resolve the issue with pelicans falling out of the sky.

John Young [00:02:22] And literally, these pelicans look like sometimes somebody shot them. They just, they don't, they don't come down gentle, they crash. They just drop like, like you pulled the rug out from under somebody.

John Young [00:02:35] So, there was a lot of speculation that went on about what was causing that. And I got involved with it because I had an interest in looking at what effect the concrete traffic barriers were having on wind flow. And so, we worked with the Texas A&M Texas Transportation Institute. We did a wind tunnel study and found out that, yeah, definitely concrete traffic barriers were affecting the wind. We took that information from the wind tunnel, we used it to inform some computer fluid dynamic models so that we could try to manipulate wind.

John Young [00:03:16] And long story short, we found out that the concrete traffic barrier that was there was funneling the wind, making a faster wind. So, if the wind speed was 30 miles an hour, the wind would hit that concrete traffic barrier and it would roll up and actually increase in wind speed. And then it would do that to about 15, 20 feet in the air. And then, as it leveled off and started to flow again, it had a downdraft.

John Young [00:03:47] And basically the concrete traffic barrier was creating a vortex where the pelicans would be flying along. If they managed to get through that increased wind speed, then they hit a soft spot of air where the downdraft in the wind would basically push them down onto the roadway.

John Young [00:04:06] So, after we identified that that was the issue, we looked at a bunch of different rail types that we could potentially use, and we had to be careful because we have to maintain safety on that bridge. And so, we had to have a rail type that would meet specific safety standards.

John Young [00:04:24] And we identified one and did more modeling and noted that we reduced that wind speed. We eliminated a lot of the downdraft.

John Young [00:04:33] So, we went ahead and put new rails on the [Carl "Joe"] Gayman bridge.

John Young [00:04:39] The Pelican Poles seemed to resolve the issue on the other [Jaime Zapata] bridge where the birds were falling out.

John Young [00:04:45] But we replaced the bridge rails and the approaches on the causeway around the Gayman Bridge, and that seemed to help as well.

John Young [00:04:54] Now we have multiple pelican events during the course of the year. It's only been two or three years now since we put the new rails in.

John Young [00:05:03] And pelicans still fall out of the sky. We still have pelican downings and landings in the road, but we feel that they're reduced from what they were.