The rubber dam on the west end of Tempe Town Lake will be replaced with a hydraulically-operated steel dam, with work starting this summer. On April 23 at the Tempe Center for the Arts, the city will give the public information about the dam replacement. Jeff Kulaga, assistant city manager for Tempe, will discuss the issue.
Ted Simons: The City of Tempe is ready to begin construction on a new hydraulically operated dam on the west end of Tempe Town Lake. Work on the new dam is set to begin this summer. Here to talk about the project is Tempe assistant city manager Jeff Kulaga. Good to see you again. This is, this summer, when this summer?
Jeff Kulaga: We look to begin site preparation probably in mid-June or so to begin construction of the west dam on Tempe Town Lake. So we are right now on the cusp of that construction project, $40 million project. It's an exciting time in the City of Tempe for us.
Ted Simons: This is a different dam than the rubber dam before. How does the new dam work?
Jeff Kulaga: Absolutely. It is a different dam. First of all, the materials are different. It is a steel-gated hydraulically operated dam. Our present dam is rubber bladders, essentially big inner tubes. This big dam will be a combination system of eight steel gates operated to move up and down by hydraulic cylinders.
Ted Simons: We are seeing kind of fast motion here. This is of the dam going down. In case like we have a major rainfall or flood? Correct?
Jeff Kulaga: That's what's very important about this dam and the need for the gate. One question we always get is, why don't you just build a concrete wall? Well, that is fine during most of the year when the lake needs to operate like a lake, and the dam on the west side here is there to keep the waters in Tempe Town Lake. But during those events, storm events where the flow is coming through the Salt River, up from Roosevelt lake and Roosevelt dam where there are releases, our Tempe Town Lake has to transform into a river. And that river has to convey the waters through the lake. Therefore, those steel-gated dams need to move up and down. They will operate on a hinge much like, I guess a drawbridge, eight drawbridges through the lake and the river bottom. And when they move down, the water is able to convey through the river channel.
Ted Simons: We saw a speed up motion camera there. How long does it take all the way up to all the way down?
Jeff Kulaga: Probably a couple of hours.
Ted Simons: OK.
Jeff Kulaga: When there's, we get a good -hour notice from SRP when they are releasing waters up at Roosevelt dam. So we get notice. We start lowering the dams to whatever level need be to pass that water, to convey that water through the river channel and then as those storms and storms subside we raise them back up again to collect the tail waters and bring back Tempe Town Lake safely for everybody to use.
Ted Simons: How long is this new dam expected to last?
Jeff Kulaga: It is steel and concrete with proper maintenance of the hydraulics, good preive maintenance, we are looking at 50 years.
Ted Simons: Is this same kind of dam now in operation elsewhere?
Jeff Kulaga: We looked at Oklahoma City -- has three or four dams using this same system. They're smaller. As far as we know right now this will be the largest steel-gated hydraulically operated steel-gate the dam in the world.
Ted Simons: By a long shot?
Jeff Kulaga: By enough, I guess. We haven't really compared but we know it's larger. We haven't really compared by how much. It is large, though. But the fabricator of Oklahoma City's dam, steel fab, they did those. They are designing ours. Schuff Steel is building and designing it. Gannett has begun the engineering and the Tempe contractor will be doing the construction. So there's a hometown organizations here designing, building the dam.
Ted Simons: This is going to be built 100 feet west of where the old dam was? Is that correct?
Jeff Kulaga: That's absolutely correct, Ted. The existing dam is under the pedestrian bridge which is enjoyed by a lot of people recreating around Tempe Town Lake right there at the door of Tempe center for the arts. The new dam will be feet west of there. We did that for three reasons. One, simply needed a little bit more space to convey the water with the new dam. So that was achieved moving it feet west. Secondly, we're able to use the existing rubber bladder dam to hold the waters in of Tempe Town Lake so the new steel-gated dam is built on dry land therefore saving money and time. And lastly, once it's complete, the waters of Tempe Town Lake will extend another feet west. So if you are walking across, riding your bicycle across the pedestrian bridge, you have water on both sides now.
Ted Simons: And when you mention the fact it's going to be built on dry land, does that also mean that the lake doesn't have to be drained, doesn't have to be messed with?
Jeff Kulaga: Absolutely correct. When we are building this new dam, the existing rubber bladder dam will be there protecting the construction site and project from the lake waters.
Ted Simons: How will construction impact the lake in general?
Jeff Kulaga: Well, it's going to, you know, moving the lake feet west is going to be a little bit bigger. The construction itself during construction over about the next months, minimal impact to the lake itself. However, we do need to relocate a storm drain pipe so the pedestrian path right there at the Tempe center for the rights will be detoured around the center for the arts for a period of time. Our goal is to keep the bridge open.
Ted Simons: OK. So minimal impact. Bird watching you are not going to be many birds.
Jeff Kulaga: Surprisingly those herons, they don't like to movement they are pretty tough.
Ted Simons: They seem to be always. For those who are relatively new here, why is this new dam necessary? Give us the story if you can quickly of the old dam.
Jeff Kulaga: Very quickly, about years, in , almost four years ago we would a rupture of one of the balloters. It drained the lake on a Tuesday night on July th. Since then, we have an agreement with bridgestone the manufacturer of the rubber bladders, essentially they are rentals. We have them for a five-year period. After that five-year period we are looking at a permanent replacement. The permanent replacement is the steel-gated dams.
Ted Simons: This is the west end. What about the east end?
Jeff Kulaga: The east side of the lake is managing, managing the water as well. There's not an issue there right now. We are focusing all our attention on completing this west dam for the community and for the city of Tempe by December of .
Ted Simons: How does it work on the east end? Is there a dam?
Jeff Kulaga: Is a dam -- there is a dam but the waters essentially hit a shoreline there. Because the river bottom is higher on the east end than on the west end, about 20 feet or so plus or minus. So we collect the waters on the west end and much like a shore of a lake or the ocean, it just fades to a couple of feed feat on the east end.
Ted Simons: As far as it could go?
Jeff Kulaga: Yes.
Ted Simons: You mentioned $40 million here. How is this going to be paid for?
Jeff Kulaga: We are using bond funding, some cash, cash that we have as part of the project. It's all in our five-year capital improvement program. It's been planned for, budgeted by our city council through their leadership. And again the goal is to get it done by December 2015.
Ted Simons: That's all the budget has all been ready?
Jeff Kulaga: Right. We have been planning for this since prior to 2010.
Ted Simons: We have about seconds left. The importance of Tempe Town Lake to Tempe.
Jeff Kulaga: It had three purposes. Flood control, recreation and economic development. A good example of the economic development right now is the state farm complex on the south shore there near ASU.
Ted Simons: All right. Good luck on it.
Jeff Kulaga: Thank you.
Ted Simons: We will be watching the construction and the birds and the whole nine yards and it's exciting times. Should be finished by the end of next year?
Jeff Kulaga: December of 2015, yes.
Ted Simons: Good to have you.
Jeff Kulaga: Thank you.
Jeff Kulaga:Assistant City Manager, Tempe;