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Discussion: Wetlands for Flood Mitigation

posted on February 5, 2009 at 5:32 PM

There are examples in the state where work is being done on watersheds through the development of tracts of wetlands.

In addition to the Port Louisa project we just saw there is the Iowa River Corridor project between Tama and Amana.  Both projects began after the 1993 floods when frustrated landowners were tired of dealing with repetitive flooding. 

So, the question is does it take a disaster, like major floods, to motivate landowners, the public and politicians to look for long-term solutions?  Also, what percentage of wetlands or other conservation efforts such as grassland need to be restored in order to be an effective tool for flood control?  And is it practical to look for solutions in the landscape or should more emphasis be placed on planning and zoning where communities can build? 

To address these questions and more is Marty Adkins with the USDA's Natural Resources Conservation Service.  The NRCS administers a large number of conservation programs for landowners, many of whom are farmers.  Mr. Adkins also manages the NRCS watershed planning and operations work in Iowa.  Jack Riessen is with the Iowa Department of Natural Resources.  Among his many responsibilities, one of them is working on floodplain management for the state. 

Gentlemen, welcome to The Iowa Journal, glad to have you here tonight.  Let's first start with the big question -- we know that there really couldn't have been anything to do to prevent the flood of 2008 but when we talk about wetlands would a wetland program, expansion program have made any difference on this flood?

Jack Riessen: I don't think so.  If you look at the 2008 floods there was such a tremendous volume of water that all the depressional areas on the landscape were already filled up when the critical rains came in June.  That was a pattern we saw in '93 as well as 2008.  You had a number of rain storms moving across the landscape beginning in April and May, it saturated everything, you had the critical rains in June and so wetlands, that type of thing, even if you had more landscape they already would have been filled up.  And so the tremendous volume of rain is just something that really, really would be hard to control through wetlands or small structures like that.

Paul Yeager: So, we just know that we had a monumental task.  Do you agree with that statement there?

Marty Adkins: Yes, I think 2008 was a special case.  2008 we had a very wet year but the year before that we had record snowfall, we had cold temperatures and then we had a lot of rain both in the spring and the summer and so 2008 was really one of those outlier years.  I think when we're talking about wetlands and flood plain areas being in use for flood storage maybe we need to be talking more about how they fit into flood damage reduction and maybe how they fit into the kind of storm and rainfall events that maybe aren't quite at the level of 2008.

Jack Riessen: I think there's a key point there.  Are we talking about reducing floods or reducing flood damages?  Floods occurred long before we came here and they'll continue to.  When we develop in the floodplain, grow crops in the floodplain, put buildings there, that's where the damage comes.  So, we really have to be looking at a combination of strategies.

Paul Yeager: And you talk a little bit about crops and we've got more than 50 million acres in production on the ag side in this state, it's a big part of our economy, a big part of our heritage.  When you start looking at targeting areas, maybe some of those farm acres, where do you begin on trying to balance out what can be taken out of production to help in some of these mitigation efforts?

Jack Riessen: I think that becomes a critical issue is where you place these on the landscape.  Small dams, wetlands can help on the localized effort, there's a lot of good things, water quality benefits, habitat diversity, where you place these things in the landscape become very critical as to how much they can help actually flooding especially in the smaller streams.

Marty Adkins: I was just going to say the landowners themselves maybe have a way of helping to answer that question because as economic damages become more than they are willing to put up with that's where we really get interest in enrolling in programs like either the Wetlands Reserve Program or the Emergency Watershed Protection Program.  They kind of vote with their feet and in administering those programs we can also maybe help direct those dollars to the places that have the greatest impact.

Paul Yeager: You hit on something there when you talk about the Emergency Wetland Program, we're going to show you a map here in a moment.  Since the floods there has been, to my understanding, 711 applications for landowners wanting to enroll some 66,000 acres in the Emergency Wetland Program and you have tentatively approved about 100 of those for those 16,000 acres.  Marty, what has that criteria been to pick, as we see the map there, those dots when we put those dots and take them out of production and put them in the program, what is the criteria to make that decision?

Marty Adkins: Well, there have been kind of two rounds of that funding.  The first rounds were really aimed at sites where we could maybe reduce expenditures for other kinds of flood damages.  So, if we had an opportunity say to open up a floodplain in an area where we might be able to reduce an impact on rural roads, that kind of thing, that was the first round. 

The second round of approvals was really aimed at lands that were not eligible for the Wetlands Reserve Program for one thing because that was another option for other landowners and so they tended to go to those places where farmland was most heavily damaged. 

There was a consideration in the ranking process given to the extent of sand deposition damage and many of those offered pieces of farmland that were most heavily damage and kind of floated to the top.

Paul Yeager: So, that doesn't sound though like there may be at the top of the watershed area.  There's a lot of those dots farther downstream maybe where rivers had come together but how important is it and does it weigh geographically as well where you put those?  Say it is on that northern tier of counties whether it's in Mitchell County or Allamakee County or Cerro Gordo, somewhere in there.

Marty Adkins: Well, the heaviest damages are going to tend to be down in the lower part of watersheds and the river basins that maybe experience some of the most severe events this year were actually in the northern part of the state.  So, there are quite a few selections that have been made in the area of the Turkey River, the Yellow River, some of those rivers in the northeastern part of the state.  Work in the other parts of the watershed though maybe has to focus on other practices other than just easements.

Paul Yeager: Jack, where do we go with those other practices or do we need to extend this program that the USDA is already doing?

Jack Riessen: Well, I think before when Marty and I were talking about some of the projects, what they call PFI66 watershed projects, what you do is they take a medium sized watershed and you look at the entire hydrology and a lot of times that ends with siting smaller flood control structures, reservoirs, that type of thing integrated with land conservation into the upper reaches of the watershed.  

In small to medium sized watersheds these types of priorities can have a very favorable effect, Soap Creek is one that's being built right now.  When you look at larger rivers, though, the Cedar River at Cedar Rapids drains over 6500 square miles.  If you look at the total amount of the water that went down the Cedar River for the three months of April, May and June it was over 14 inches for the entire watershed.  So, if you can imagine trying to store the type of flow you need to actually significantly reduce that type of a flood it becomes very difficult.  It's a matter of scale. 

Some things work very well on smaller watersheds and the upland treatment certainly has a role in that.  But when you get to larger rivers I think you kind of have to accept the fact that you're going to continue to have these very large floods and we need to better plan around those large floods to reduce the damages.  Maybe that includes staying out of the floodplain, maybe it requires a higher level of protection for what you do there. These are some of the questions we're asking right now.

Marty Adkins: And there are other benefits to doing work up in the watersheds.  I think we're talking about flooding but there are a lot of good things that people are already doing and there's certainly room to make improvements in what we're doing and if we're talking about the way farmland is managed it is partly about managing water but it's also partly about preserving the soil resources. It's partly about maintaining a place for wildlife on the landscape, for managing water quality, for improving water quality so there's a lot of really good reasons to do good watershed management, flooding is just one of those.

Paul Yeager: I think there is a term that goes with what you’re saying, you call it hardscape landscape or maybe the planning and zoning end of these things.  Some of these are more immediate, some of these are longer term.  Which one of those works best in an immediate situation that we can do right now?

Marty Adkins: I'm not sure we would do one without the other.  I think they're both really important.  The planning and zoning, good floodplain management is so important for the large low frequency events.  But the ones that we seem to have more often than we think we are going to have or should have the work up in the watersheds, they have greater impacts on localized areas, they have greater impacts on the more usual kinds of storm events that we have and they also provide kind of a series of other benefits.

Paul Yeager: My understanding is that there is a flood mapping, it's a $15 million project, that would be the lowest estimate to get that, a minimum to get that started.  Tell me about what a flood map would mean in this discussion and helping us decide what type of treatment we need to do to whatever area.

Jack Riessen: Well, one of the things that flood plain management -- to stay out of the flood plain you obviously have to know where the flood plain is.  Approximately a third of our counties in the state don’t' even have a rudimentary floodplain map.  Cities like Cedar Rapids, Iowa City, Waterloo, they have had fairly good floodplain maps for a number of years. 

That's not to say there shouldn't be some improvements there and I think there are some things that we should be showing on there we don't currently do.  The $15 million you're talking about was primarily intended to provide maps where there currently aren't any flood maps or where the maps are very, very cursory and rudimentary to provide a better degree of mapping for those.

Paul Yeager: So, is there a certain area of the one out of three counties that doesn't have one?  How do we target who should -- say we didn't have the money to do it statewide where do you pick to say if Cedar Rapids already has one, Linn County already has one let's go to Benton County where they don't?

Jack Riessen: I think first of all you have to steer to probably where it would do the most good, where there's development pressure, that type of thing.  Most of the areas that don't currently have maps are the western counties, the western third of the state. 

But that does raise an interesting question.  If you're going to have a statewide mapping program do you do it on a county by county basis, do you do it on a river basin basis which makes a little more sense?  Those would all be issues that still would have to be decided.

Paul Yeager: Do you want to weigh in on that one at all?

Marty Adkins: I think Jack makes a good point.  The places where the most development pressure are that's the place where we're going to have the most immediate impacts.

Paul Yeager: We also talk about when you talk about planning and zoning there's been urban sprawl in certain counties.  You go anywhere below where they're having a flood and they'll say it's that town above that has all the concrete now.  But that's another discussion for another day.  But we did talk about farmland and we talk about tiling purposes. 

There are some environmentalists that will say tiling is the worst thing that you can do for any wetland protection.  Then you've got the ag interests who will say yes but we are feeding the world in what we're able to do on this ag land.  Where does that balance fit into this discussion?

Marty Adkins: Watersheds are complex systems and the use of agricultural drainage is one factor in how you manage a watershed.  Artificial drainage certainly has had big negative impacts on wetlands and on wetland wildlife and things over the course of Iowa's history. 

Artificial drainage has also made possible the cultivation of many millions of acres that have contributed a lot to Iowa's economy and Iowa's way of life and has meant a lot to the world.  There are things that we need to think about with tile drainage or with artificial drainage generally about how we manage those systems and how can we mitigate some of the negative impacts of them whether it's nitrate loss or whatever the issue is.

Paul Yeager: I've got only two minutes, hard to believe and this discussion flies by, but I want to briefly talk about levees and dams and those types of manmade structures.  When we saw the piece we talked about the Louisa County area.  There's levees, there's dams in there.  Where does that play in this discussion right now?  Do we need to be making repairs to these things that apparently didn't work in keeping back flooding?

Jack Riessen: I think the question is should we make repairs to some of these things.  I think the answer some places is yes, some places it's no.  Some places it doesn't make economic sense to do that.  Structural flood control will still remain a significant tool to reduce flood damages.  But I think most of those major projects have already been built that show economic viability. 

So, I don't think we're going to see a lot of new major flood control, structural flood control works.  We're going to have to look more at things like upland treatment, floodplain management, other things like that.  Flood insurance is another thing.  Very few people carry flood insurance.  I don't understand that.

Marty Adkins: I think Jack hit the nail on the head.  Levees are one tool, one way of managing floodplains.  There are places where they are appropriate where you've got high value assets there and you don't have other choices.  There are other ways of managing that risk.  Sometimes it makes sense on farmland but there are times where the history of maintenance on a levee may tell you that it's time to do other things as was the case with Levee District 8.

Paul Yeager: It's an old enough levee, it's been repaired 12 times, we just can't keep doing it any more and it hasn't worked in the past.  Okay, I see what you're saying.  Very good.  That's Marty Adkins, he's with the U.S. Department of Agriculture's Natural Resources Conservation Service and Jack Riessen is with the Iowa Department of Natural Resources.

Tags: agriculture conservation Energy/Environment erosion floods Iowa USDA water weather wetlands


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