stormwater wetland project creekview case study

creekview stormwater wetland urban conservation practices

the creekview project is an innovative initiative that redirects a large amount of stormwater drainage from the city of ankeny to a designated area of fourmile creek. this effort aims to boost the natural environment and water quality by expanding the greenway park system and integrating wetland features.

the city of ankeny, polk county, the fourmile creek watershed management authority, and snyder & associates, with a local developer, collaborate on this project. the developer donated the land, while the county is leading and financing the design and construction. the city will own and maintain the site, expanding the growing greenway park system covering nearly 1,000 acres of floodplains along fourmile creek. the site will include wetland features, riparian restoration, and educational signage.

during a discussion, steve klocke, p.e. and nichoel church, pws, with snyder & associates, along with john swanson, water resources supervisor for polk county, shared insights into the partnership’s origins and the significant impact of an unusual permit that made it all possible.

 

 

podcast agenda

• background information for stormwater wetland site (01:16)
• design and permitting services offered by snyder & associates (03:58)
• acquiring regional permit 39 (09:05)
• ensuring effective communication with the army corps of engineers (11:02)
• flexibility in making design adjustments (12:51)
• creating a roadmap for future projects (15:10)
• creekview stormwater wetland project update (16:48)

creekview stormwater wetland

steve klocke (00:18):

hi there. i’m steve klocke. i’m a civil engineer in the water resources group at snyder & associates. i’ve been here with snyder for a little over 20 years, and with me today are john swanson with polk county and nichoel church with snyder & associates. and we’re going to talk about our creekview project. john and nichoel, do you guys want to give a little introduction of yourselves?

nichoel church (00:38):

yeah. so again, nichoel church. i’m an environmental scientist here at snyder. i’ve been here for about 11 years, and my role and my discussion for this podcast is going to be talking about this project from an environmental standpoint and how we rolled through with permitting.

john swanson (00:55):

yep, and my name’s john swanson. i’m the water resources supervisor with polk county 世界杯足球比赛预选赛 works. i’ve been working in the area for about a dozen years with a variety of different roles, and currently, with my job at the county, i oversee all of our water quality, flood control, and general water resources projects, and all also help provide assistance to all the communities of the des moines metro through our watershed management authorities.

background information for stormwater wetland site

steve klocke (01:16):

all right, thanks, guys. so, the creekview stormwater wetland project is something snyder is currently working on in the design phase right now. it takes its name from creekview drive on the eastern side of ankeny, iowa. the site’s located along little fourmile creek, and the watershed that flows to it is about four 50 acres, more or less fully developed at this point with the mix of residential and commercial properties. so, this was identified as a great site for a stormwater wetland. it receives the runoff from that developed area, and we can take that flow, run it through the stormwater wetland, get some detention and some treatment, and remove some pollutants. so i guess, john, do you want to discuss a little bit how you guys landed on this site and how it came into being?

john swanson (02:02):

yeah, for sure. it has kind of a unique history in that it’s currently owned by a local landowner and developer, and part of his property was in the flood plain. he kind of had the realization that it wasn’t really a good use for his development goals. he actually first reached out to our county board of supervisors because we’ve done a lot of land acquisitions along fourmile creek and the floodplain and in the development of a greenway system. and before we know it, we were sitting down with the landowner and our conservation department and talking about potentially acquiring or donating that land to the county.

long story short, there wasn’t great connectivity. it’s a little bit further north than the rest of our greenway properties, but as my team got involved, one of the first things we noticed was this tributary coming to fourmile creek from the west, from the city of ankeny. again, right off the bat, we saw a relatively large drainage area. most of those areas are older developments that were built prior to stormwater requirements. we’ve had this constant effort in fourmile creek, where we have a lot of flooding and water quality concerns, to try and intercept water and slow it down. and so the story kept going.

we brought on snyder & associates to do some feasibility for us to perhaps divert that water onto this property and build a stormwater wetland. and being within the city of ankeny not having good connectivity to county property, we again quickly realized that there was some good connectivity to ankeny property. as the conversation continued, we looked at, okay, let’s not just donate the property, but let’s see if we could build a wetland on it. and, low and behold, the site worked. feasibility was good for a stormwater wetland.

polk county began doing some fundraising, and as we sit today, polk county has fundraised about 1.5 million, and we’ve worked out a deal where the county is going to come in and construct the wetland and oversee the construction and the funding of it. and the developer and landowner are going to donate the land to the city of ankeny, who is then again, upon completion of the wetland, they’re going to actually own and maintain it. so truly, it is a partnership between the city of ankeny, polk county, and this local landowner and developer.

design & permitting services offered by snyder & associates

steve klocke (03:58):

yeah, thanks, john. that’s a great description of how things kind of came into being. and i know early on, one of the things you asked us to do was look kind of high level, do a real conceptual design, and screen the site. and that’s something that we had done early on, and we very quickly realized this looks like a really promising site. and then, as you said, you guys kind of took over again and started doing the fundraising and getting things going in the background before we really got going on the engineering side. then we kind of got the green light to get started on the design after that. so, once we got rolling on the design, we started working on a kind of conceptual layout and started working with nichoel on the environmental impacts as well. we started looking into, okay, you know, this is going to require permitting with the corps of engineers and also some floodplain work as well. and so, we did an initial layout. and nichoel, do you want to talk a little bit about what you were finding on the site, what the challenges were there, and how we did some coordination with the corps early on to try and identify what the challenges were going to be?

nichoel church (04:58):

yeah, then the real fun began.

steve klocke (05:00):

yeah, that’s right.

environmental permitting

nichoel church (05:01):

we moved forward with environmental services, and that included a wetland delineation and an ordinary high watermark delineation along the stream. what we found were a couple of ditch wetlands feeding into the stream, but it didn’t actually have wetlands along the channel, which was good for our project because we were looking at an off-channel wetland. any wetlands that would have been there today, we would’ve had to make sure were improved and remain so through this whole process. this wouldn’t have been a problem. it’s just something we would’ve had to make sure of. so, we didn’t delineate any wetlands along the channel. but we did find that stream, and it was really important for us to know what the impacts to the stream would be both in acres and linear feet. so, we worked with our design team and our engineers and figured out, okay, here’s what we’re thinking for a location as far as this inlet and outlet for the stormwater wetland.

well, i had some initial concerns. so rolling into permitting, you know, we were going to need a permit for this project, a section 404 permit from the us army corps of engineers for under the permitting activities to jurisdictional waters of the united states and just ensuring that we’re offsetting impacts that are proposed. so we worked with steve, and we also had discussions with john, just trying to understand where we could be at impact-wise and what we were looking at for a permit. we thought that we were probably going to have to modify our design a little bit to meet some regional permits. but it was really working collectively with our client and our design team to make sure that everybody was on the same page.

john swanson (06:35):

and i think it played out well. i think from the initial feasibility, steve and his team looked at doing a diversion structure because of the large drainage area and not actually placing the wetland. and that side characteristics set that up well. trying to divert water out of that tributary and getting into the wetland and then as it flows through the wetland and then eventually out letting back into that tributary, i think helped with that next phase, the permitting.

then also, like thinking about this site, specifically it being in the floodplain, we also knew that filling or building berms higher elevation than there were currently was not going to be a realistic option for permitting. so again, from that early onset, the plan was a diversion structure to get it out of the trib and then gain our stores through excavations. then, it kind of all fell back to that partnership where the landowner plans to use those spoils on adjacent properties for fill. so we didn’t have to truck it very far. so i think from step one, like kind of understanding those site characteristics and then understanding the next step of what we’re going to have to achieve for permitting, pointed us in the right direction, which panned out very well, i think.

nichoel church (07:38):

oh yeah.

initial design & constraints

steve klocke (07:39):

yeah. i think from our initial design, we had laid out, you know, our initial concept and had proposed some things that, as we were talking to the corps, we were discovering really that was pushing us in the direction of having to do a lot of potential mitigation. and then, as we looked at it, we’re like, well, can we tweak some things on the design to minimize those impacts and realize that without a lot of compromises here on the design, we can really make some changes to how our design was set up.

ultimately, we ended up eliminating the need to do any kind of mitigation. i think we were looking at, you know, potentially more than a hundred thousand dollars worth of stream mitigation, and by making some minor revisions and moving some things around a little bit, we were able to completely eliminate that requirement and satisfy the corps requirements.

i know we also had some constraints. john, you mentioned the floodplain. so we did have some limitations on placing fill out there. we had some challenges as far as meeting all the design requirements we’d like to meet with complying with the stormwater management manual. but ultimately, i think we were able to hit most of those key points that their stormwater management manual identifies for stormwater wetlands, and we also worked with the property owner to make sure that they were satisfied with the final design. you know, adjusting our design as needed to satisfy them and make sure that they still have a site that is developable and valuable to them. so ultimately, you know, it’s all about communication and cooperation between everyone and coordination.

obtaining regional permit 39

nichoel church (09:05):

yeah, and i one hundred percent agree. i feel like had we not been in communication with the corps of engineers with what we were thinking from very early onset and then through design and those changes and why we made those changes, i feel like things would’ve gone very differently. so, in talking with the corps, we did pursue a regional permit 39 (rp 39), which is actually a pretty rare permit. they don’t authorize that permit very often for projects. the reason why is because not a lot of projects have off-channel wetlands. usually, you know, the berms are placed on the stream, and that backs up water, and that creates a wetland. so, these off-channel wetlands, not only do they add value, you know, they’re a water quality treatment facility reducing nutrients in our waterways, but they also provide flood storage capacity. it’s just a huge benefit. i feel like the corps really saw value in that.

once we figured out basically where we wanted to outlet the structure for the wetland back into that channel so that there wasn’t that much of an impact to the stream at all, i think we had 140 feet or something of a loss. i feel like once we figured out their requirements, we were able to tweak things just a little bit, and communication was the key. the landowner was happy with it. our client was happy with it. we were happy with it, and just a win all the way around.

john swanson (10:23):

it almost sounds cliche, but the common theme of this project was partnerships and communication. i think when we got through the initial designs, we’re thinking we’ve got to get into this permitting. we all sat down and were like, there’s this regional permit 39, which includes involvement with the iowa department of ag and land stewardship (idals), which they’re predominantly using for agricultural wetlands. and so we just simply called a meeting with idals, they were one of the funders, we did get an urban water quality initiative grant for this wetland, and we said, hey, we’d like to discuss, would you be supportive of us pursuing this? and i think the response was an excellent response. they’re like, yeah, if it works for you guys, we’re strongly supportive. like, we just want to see more projects getting done, and if that’s an avenue that works for the corps, we see the value.

john swanson (11:15):

although when you think of nutrients, you’re generally thinking of agricultural settings, but we know there are nutrients coming off this sub-watershed into this wetland. and so with that support from idals, again, we want to communicate with them like, “hey, are you guys support of this?” and they gave us the full go-ahead.

clear communication with the army corps of engineers

john swanson (11:02):

and then being kind of proactive. nichoel, could you kind of walk us through your approach to bringing the corps in, sitting down, and talking to them about this specific project?

nichoel church (11:22):

yeah, so we really thought rp 39 would be applicable for this project, but again, they don’t authorize this permit very often. so i think they were really hesitant to even consider it. and had we moved forward with our prelim design or our concept the way that we had it, there definitely would’ve been mitigation, and we probably would’ve taken another year to get a permit because it would’ve been thrown into the individual permit category, which nobody wanted. and so i feel like when we were talking about this and john, you were flexible, you know, you weren’t hard and fast on this wetland has to outlet here and it has to do this. that flexibility really allowed us to move forward with the conference call with the corps and setting the stage for communicating with them. like why are we doing what we’re doing? what is the purpose of this project? what is our overall intent, and how are we going to accomplish that? and then talking through what we were proposing for design and then to their suggestion, they were like, if you could scale this outlet higher and along the channel so that there wasn’t as much of an impact to the stream, you know, stream loss, they were willing to work with us on it. i feel like that was like the golden ticket, and everybody was on the same page and understood. but without that conference call, you know, just emailing back and forth, you’re not going to get the answers that you want. you really need to pick up the phone or set up that meeting and know what you’re asking for. i feel like once we knew what we were asking for and we could elaborate on how we were going to accomplish it. they were much more open to this permit and authorizing it.

design adjustments & flexibility

steve klocke (12:51):

yeah, i agree, nichoel. i mean, from the design side and the engineering side, having that call finally gave us the direction that we needed to know in order to adjust our design and, you know, start looking towards minimizing the potential for mitigation and trying to work away from the needs for an individual permit. and as we did that, we kept finding, oh, we can actually, you know, reduce this impact more and more and found ways to make that happen until we were ultimately able to get below the mitigation threshold and get permitted without any need for mitigation.

nichoel church (13:20):

that’s right. and it really took flexibility on john’s part and your part because, you know engineers, once you have a set outlet, it’s hard to change it because you already had the elevation, you already knew where it was going to outlet to, and how that was going to affect fourmile and all of those considerations. and then it was, okay, what if we were to outlet it where we ended up doing, like what does that mean and what other considerations should we have?

john swanson (13:43):

so, we have the diversion to put water from the tributary into the wetland, and then the water flows through the sinuous wetland and goes through the stormwater wetland. that is outlined pretty traditionally in iswm. so, it seemed like the big meeting in the middle with the corps was moving that outlet as close as possible back to where the inlet was. so we’re impacting the minimum amount of stream, which was, again, a rather significant change. not to downplay what we originally had outlined. but moving it back there didn’t take that long to re-figure out, but it seemed like the corps was like, “yep, that’s exactly what we wanted.” that’s what they shared with us, and we did it. and they’re like, “yeah, that’s a great design. let’s move forward with not only minimal mitigation but no stream mitigation requirements.” so i think we’re all maybe a little bit surprised even about how smoothly that went. but common sense for me as a non-engineer was like, yeah, that makes sense. that’s a good way to minimize stream impacts with this wetland.

nichoel church (14:31):

yeah, and i definitely don’t want to oversimplify the fact that we were in clear communication because, i mean, i remember steve and i discussing this project in february, and we had our call with the corps in march, and then we submitted additional information back to them in may, early may, and then we got our permit at the end of may. so it was just kind of one of those projects where we worked hard to get to where we did. and i definitely don’t want to undersell that by any means because everybody was flexible. there were changes made. i mean we had to go back to our design and fix our outlet. it’s just what had to happen. but that cost or that time was worth it in the end.

steve klocke (15:09):

absolutely.

creating a roadmap for future projects

john swanson (15:10):

and then, as a team, we have funding going as well from the iowa finance authority, from idals, from polk county, the urban conservation is overseeing the design on behalf of idals, ankeny who’s going to own and maintain it. i think, just being clear, when we shared communications, we tried to make sure all those key players who have some type of involvement in the design were on board. we set that stage at the very beginning, and now it’s almost the expectation that everyone knows what’s going on. and again, i learned a lot from this, like how can we apply this to other projects we’re doing. a big part of it was just knowing who needed to be aware of these changes and get everyone’s approval at the same time. this was an example of it moving rather smoothly. not that anything was perfect because there are always little hiccups, but overall, for how complex this one was or is, it’s been really fun to kind of see this good partnership pull through it.

steve klocke (15:54):

i think this definitely is going to be the roadmap for future projects like this how. that coordination and cooperation goes through permitting and just being able to be flexible with the design. and i think, hopefully, we can do the exact same process on future projects, and they’ll go just this smoothly.

nichoel church (16:10):

and from the environmental standpoint, i agree. now we know if another off-channel wetland comes through, we know exactly how we’re going to permit it. you know what i mean?

john swanson (16:19):

yeah. and it was kind of fun and difficult in that we discussed this, and really, there were no examples for us to work off of. like, there was some almost relevant agricultural examples, but it was kinda like this was a first crack at how do we do this diversion stormwater wetland and get it back into the channel. it was a little bit of a learning curve, but it was interesting to see you guys work through that and come up with a unique diversion structure that like, as far as we could find, it hadn’t really been done anywhere else.

nichoel church (16:42):

good job, steve. yeah.

john swanson (16:43):

good work, steve.

steve klocke (16:44):

well, it was fun to see everything kind of fall into place.

nichoel church (16:45):

i love it when a plan comes together.

creekview stormwater wetland project update

john swanson (16:48):

so, as we sit today, we’ve come a long way. we’re sitting at about 90% design, where we’ve really gone through all the big design hurdles. we’ve got a lot of our permits in place, especially the 404 working through floodplains. to be honest, probably for me, the hardest part of this project is that it has turned into a 35-page development agreement between polk county, the developer, and the city of ankeny, just again to really clearly outline everyone’s roles. so we’re just finishing getting that approved by all the different parties, and our hope is to get this project bid out here and get it built this fall. and for us to have a beautiful wetland, growing some natives by spring is what we hope to see.

steve klocke (17:22):

yeah, this really has been an exciting project to work on. well, john, nichoel, thanks for chatting here. really appreciate your time, and thank you for listening.

john swanson (17:32):

thanks, everybody. thank you.