Conceptual and Feasibility Design Study

One of our most common tasks at the outset of a whitewater park project is to initiate the effort with a Conceptual and Feasibility Design Study

My name is Dusty Stinson—owner and founder of Coosa Outfitters in Gadsden, Alabama.  Our outfitter’s store has the distinction of being the best place to buy whitewater boats and equipment in the “Store not near Whitewater” category.  We are located just off of interstate 59 and have a thriving business in spite of the fact that there is no whitewater in this town today.  I believe that our existence alone showcases the opportunity to create whitewater in this town.  We already know that whitewater people come to Gadsden; I want to build a whitewater park here so that they will stay.

Gadsden is a former steel-mill town.  We’re the type of place in which you would least expect to find a whitewater park.  People here are traditional and our economy has historically been based on traditional means.  Now that the steel mill is gone things are changing in Gadsden—we are proud of our heritage as a manufacturing center but would also like to evolve our economy to the realities that now surround us.  One of the ways I’d like to do this is to develop a whitewater park that showcases our Town’s history and that draws people into town to learn a little bit about us and maybe drive our economy a little by staying in a hotel or eating in a restaurant.

I worked with my Town to try and find funding options for the project through a number of differing avenues but, to be honest, a whitewater park is a new concept for most folks here and it was hard to gain traction.  In the end I read about Scott Shipley at S2o Design in a magazine and began to work with them to see if they could help our project develop a vision and get off the ground.  Gadsden was willing to foot the bill for a site-visit and concept design study and Scott flew out to meet with myself, the Town Mayor and Town Manager, and the local Tourism Director.

Within six weeks S2o had identified a site, developed a concept design, project cost, and report that described the challenges and opportunities for the project.  This information mapped the way-forward for our project by giving me something I could speak to—here is what the project looks like; here’s what it does; here’s what it costs; and here’s how we get it moving.  This was something that we could use to get the project off the ground.

The design that S2o used was also highly innovative.  S2o chose a site that was at an existing dam and created a design that would leverage the energy there while providing for fish passage and improving navigation on our creek.  The site also had ready-made raw materials to create access, parking, and streamside amenities.  My favorite part of the project was S2o’s suggestion—and architectural rendering—that utilizes the old pump-house located at the dam as a possible future vendor operation.  This was exactly the kind of design that would drive visitors to come of the Interstate and experience both the whitewater and a piece of the town’s steel working history.

The in-stream design was also innovative in that it uses adjustable obstacle systems to tune the wave for varying flows.  I needed a park in town that would work at low flows for tubing and lessons and at higher flows so that people would come here to boat when the surf was “up”.  This high-tech solution met all of these requirements and more.

Dusty Stinson

Coosa Outfitters


Work with your local town or city to get these things started.  Its something that is going to benefit everyone and having your City on board from the start is going to avoid a lot of heartache later

Your first objective is to get this Conceptual Design Study done.  The last thing you want to do is be in the Mayor’s office or a town council meeting trying to sell a project that is completely abstract—you need a plan, a cost, and a route to completion.

Understand your users and design to them—S2o did a great job of this, they understood our Town and so leveraged our Steel-mill Dam and Pumphouse to showcase our history, they understood that we would draw people from the highway who were not yet boaters so designed for tubing and rafting, and they understood we wanted whitewater for the expert as well as beginner so innovated an adjustable design.

Loving a Whitewater Park

Whitewater Park User
Whitewater Park User

A write-up from one of S2o Design’s happy whitewater parks users.  We’ve heard from many different users who ended up loving a whitewater park:

I’m Michelle Kvanli, one of the founders of Red River Racing in San Marcos, Texas.  We are a non-profit organization that works to get people into kayaks—some for the purposes of going on to be champion racers, some for the joy, challenge, and therapy (yes therapy) of being in a kayak.  We run trips around the country and internationally, but base out of San Marcos.  Our property abuts the San Marcos river just downstream from downtown.

The Rio Vista dam has always been a high-point of our program.  It was a simple single drop structure until it failed in 2006.  We called our friend Scott Shipley, now of S2o Design and Engineering to come work with the City to fix the dam and preserve our best whitewater.  S2o did more than that and created an all-access whitewater park that is used by thousands of people every year.  These folks swim, wade, inner-tube and kayak at the site on a daily basis.  In fact, the new park was seeing so much additional usage that they added lights so we could paddle at night.

The park has had a tremendous effect on our program and on our town.  We now have slalom gates at the Whitewater Park year round.  This has allowed us to host national-level slalom events such as the 2008 Olympic Trials qualifier.  It has also supported a growing group of active racers that use the site.  We also have play boating and surfing at the park.  The draw from this park has had a tremendous effect on our town.  Talk about economic impact!  The park is used by so many people that the City hired additional rangers to help monitor the crowds.

The park has also allowed us to play a key role in the Wounded Warrior Program.  Red River works with returning vets who have been injured or who are still working to integrate themselves back into being home.  We work with them to get them into boats and challenge them—both on the water and off—in an effort to help them find some stability in their own lives.  This is a very exciting program both for our City and our Country so I am excited that the San Marcos Whitewater Park allows us to make this happen.

–Michelle Kvanli, Co-Director, Red River Racing


Bring in a designer like S2o who will think of your park holistically—not just as a whitewater park.  Scott’s work to remove the concrete walls and create access for people of all ability levels adds a lot to how this park is used.

Design for all types of visitors—not just top level kayakers.

Create spaces for events and for programs—these are what provide the most impact to your “dry side” community!

Welcome everyone to your park including the inner-tubers and waders and BBQ’rs.  This is not just about top level niche athletes!


Physical Modeling of Hydraulic Structures


Physical Modeling
Physical Modeling of the London 2012 Whitewater Park

Physical Modeling of Hydraulic Structures

S2o specializes in the physical modeling of whitewater parks and the Physical Modeling of other Hydraulic Structures.  Here is a summary from one of our clients about the Physical Modeling of the London 2012 Olympic Venue at the Lee Valley Whitewater Centre:

Physical Modeling of the London Whitewater Canoe Slalom Venue

I own and operate an engineering firm in the United Kingdom.  Ostensibly, I would be a competitor to S2o as I also plan, design, and implement whitewater parks.  Instead, however, we tend to partner on projects around the world.  S2o’s business model, much like my own, is unique.  We are engineering firms that are formulated to fit seamlessly within a larger design team.  On many of our projects we team with local site/civil engineers as well as contractors, electrical engineers, architects or whatever the case may bring.  Our role—and one that S2o manages very well as well—is to make that larger team stronger and to bring unique expertise in white water design.

S2o and I have worked together on several projects including the London Olympic Park located in Lee Valley near London.  The London Park was a rush project as, by the time we became involved, construction had already started and design work had lagged.  What was needed was a two-part team, one to manage the project from the UK side—going to meetings, understanding client needs, and coordinating deliverables.  From the other side we needed hard data and we needed it quickly.  We needed computer and physical models that would substantiate our design and design changes and we needed tools that would convince the Olympic Development Authority and its stakeholders that these whitewater channels would meet, or exceed, their specifications.  What we needed was a professional design team that was going to get this job done, and done accurately and quickly.

As a team we hit the ground running and worked seamlessly to create what has been universally called the “best, and most modern, whitewater park in the world”.  S2o’s design process, advanced software, and modeling techniques meshed seamlessly with our own such that, though we live on opposite sides of the Atlantic, we were able to collaborate effortlessly.  Within three weeks we had created the necessary computer models to show the client that we needed a physical model, within six more weeks we had designed and built the world’s largest physical model ever constructed for a whitewater park.  It was a 1:10 Froude Scale model constructed at S2o’s facility in Boulder, CO (USA) and it gave us a place where the British Canoe Union, the Olympic Delivery Authority, and other stakeholders could wade into the future Olympic Channel and measure and evaluate the velocities, the waves, the eddies, and other whitewater characteristics with their own hands.  That one model was all it took to move a project from stalemate, to approved design by all parties.  Within 12 more months we would paddle on that same course as it was being approved by the International Canoe Federation for competition for the next games.  This was a project where the Physical and Computer Models—and the professionalism with which they were made—defined the project.


Start with the best design team you can find—one that has completed projects accurately, on time, and to the expected standard.  You don’t want to change mid-stream and expect a rush job.

All great whitewater parks are team efforts.  You need to pick a whitewater design team that works well as a team.  The best metric of this is “how many projects have you finished recently?”  If they’re getting projects done, they are good teammates.


Designing Whitewater Parks

Whitewater Park Design
Whitewater Park Design

Part of the process:  Michael Williams, Design Process

A quick discussion from Michael Williams about the process of Designing Whitewater Parks.

Liquid Design was the project lead for the design team on the Charlotte Whitewater Park.  We were directly responsible for the project management and coordination of over 24 various consultants and specialty consultants for the design and construction administration of the U.S. National Whitewater Center located in Charlotte, North Carolina.  We were also the master planner for the 350 acre site and the architect of record for all building structures.

These projects are mammoth undertakings.  Project management is the key element.  You must have someone efficiently guiding the process that has experience in leading it and you need team members that can work as a part of that team—doing their part on time and helping the remainder of the team to do their parts.  The reality of this project type is that not everyone truly knows what the end result will be.  For example the Pump consultant is good at what they do on a daily basis—they move the water from the bottom pond to the top.  However, they really don’t understand what that means when you have to use the pump system to move over 1,000 people on rafts.  That is why experience in this project type is so critical.  This process is about understanding the holistic design solution and ensuring that the client gets what he’s paying for that is so important.

One consultant that you do not want designing in the dark is the whitewater engineer.  That is why S2O was a key part of the process and a part of our lead design team.  They understood the holistic design solution and exactly how the whitewater components fit into it.  From day one they helped shape and mold design decisions that made the product better.   Their high-tech team provided not only drawings that actually could be built but their design solutions worked, critical for clients who are ready to start producing revenue.  Also, their use of state-of-the art and industry standard software allowed us to share design documents so that final assembly was easy, accurate and timely.

I was so impressed with S2O’s work ethic and creative vision that when they ask me to join their global team I signed up without hesitation.  It didn’t hurt that I love this unique project type and working with S2O allows me to work with talented individuals who share this same passion.

Michael Williams

Liquid Design / S2o

The Future for Whitewater Parks, both in-stream / river diversions and man-made “superparks”, is bright.  The following is a small list of what I think will be key elements for future whitewater park development;

  • Incorporation of Green Technologies / Sustainability into the design—this is the wave of the future.
  • Interwoven in the Existing Urban Landscape to create a lifestyle park that accommodates outdoor enthusiasts in an urban setting.
  • Adaptable and updateable innovation:  The technology of the sports themselves will evolve and become more dynamic.  Systems like the new Rapidbloc ( system allow for state-of-the-art channels far into the future.

Uniqueness:  Just by the nature of competition the parks will have to have the longest, fastest, and biggest of something for customer retention.

River Corridor Master Planning

Uncompahgre River
River Corridor Master Planning

Discovering the Uncompahgre River Corridor as a community amenity

S2o has led, or has been a team member, on a number of river corridor master planning efforts.  These projects serve to plan a corridor respecting the river’s natural morphology, and the habitat that it fosters, and serves to integrate the community with this river in a way that allows for recreation, access, smart development, and the preservation of beautiful natural areas, amongst other priorities.  This is the story of one of our projects as told by the team we worked with:

The City of Montrose is located along the Uncompahgre River.  Historically, this City supported agricultural and industrial land uses. To this day, gravel mining, for example, remains a significant source of income, supporting the growth of surrounding mountain towns and resorts.  Over the past decade, commercial and residential housing developments have in-filled closer to the river, largely isolating the river from public access. Montrose responded to community interests in protecting and enhancing the Uncompahgre as a public amenity by investing in planning with the support of Great Outdoor Colorado lottery funding. Currently, the river is only occasionally floated due to limited public ownership of the adjacent property and lack of access points. Montrose is just a pass-through for those visiting the famed M-wave on the Gunnison River outfall. Our project was tasked with improving public access and usage along this river corridor.

As a landscape architect and principal with DHM Design, I led the effort to prepare a master plan that describes a vision for the future of the Uncompahgre Riverway through Montrose by building on the existing natural characteristics, urban connections and broad community support. I hired Scott Shipley to examine the potential for the river to host whitewater activities. Scott found that the river characteristics support a variety of potential features and that the flows regulated by releases through the upstream irrigation system and reservoir provide consistent levels late in the season when many other rivers are low. Our team was also augmented by Walsh Environmental for ecological assessment and RPI Consulting for community input facilitation.

Scott provided a well attended presentation of whitewater parks around the world and the benefits they bring. The Montrose community showed tremendous interest in having their own whitewater park, not only for their own recreational use, but for events and spectators. Montrose supported the idea of a whitewater park drawing tourism and awareness of the larger river corridor as part of their identity. After examining the corridor with us, Scott described a number of possibilities ranging from family friendly tubing features to a competition worthy challenge course.

Master planning for a community is not easy—it can be especially difficult when including a dynamic amenity such as a whitewater park.  These parks have the potential to host extremely well-attended events.  As a potential draw to many people, each chosen location must fit within the community infrastructure, anticipating the need for vehicle and pedestrian access, parking, and restrooms. River banks can be enhanced to provide paths, hardened points for access and informal seating through the deliberate placement of boulders. Within the larger community, Montrose is particularly interested in providing a draw that supports river oriented cafes and retail shops.

With many features possible, the challenge is bringing them within reach of tight budgets. Our team identified an ideal opportunity by selecting an existing park to include our future Whitewater Park.  In this way, with relatively low investment, whitewater elements could be introduced without re-investing in infrastructure and parking.  This locationquickly gained the benefit of greater visibility and increased tourism that would in turn support additional investments. As part of a collaborative effort, the master planning process started discussions with the water district, Bureau of Reclamation, City engineering, and other agencies that have the potential to partner for the replacement of aging structures in a way that weaves whitewater features into a solution that will have many benefits for this little City that reach far beyond the scope of creating a simple play-wave.


Design of whitewater parks must consider potential impacts to the surrounding community in terms of traffic, access, parking, and public access.

By drawing attention to the whitewater features, awareness of the entire river corridor is gained, supporting investment in the overall health of the river system.

Partnerships hold great potential to bring whitewater elements within reach with cost sharing.

Collaboration with the widest range of river stakeholders is critical to gaining support for a successful project.



Economic Impacts of Whitewater Parks

economic impact table

I initially contacted S2o Design and Engineering about helping me to create a vision for a pumped Whitewater Park in the Southwest.  We accomplished this task with such a large degree of success that it has opened a tremendous can of worms down here.  The site plan created by S2o is so attractive that we literally have people from the surrounding Towns and Cities trying to get us to move our project to their location.  S2o identified our customer base and designed a profitable concept around our target audience—this is a project that everyone in our region believes is a clear success.

We are now in the process of working with our local City to try and solicit funding for the project.  We are targeting funds from a variety of sources including local government support, state and federal grants, and investor financing.  We expect our final funding portfolio to be a mixture of these options.

As a part of the process of soliciting funding we have needed to know three key elements related to the economic impacts of whitewater parks:

The first question was, “how many people in our area like to raft and how many of these folks are likely to come visit our site if we build this thing?”  In order to understand the answer to this question we commissioned a Market Analysis from S2o Design and Engineering.

The second question we needed to know the answer to was, “If the expected number of people show up, will our venue be profitable?”   In order to understand the answer to this question we commissioned S2o to undertake a Business and Market Analysis.

The last question we needed answered is, “how will the visitors that come to my park affect the economy of the surrounding city and region?”  Our host City wanted to understand these effects so that they could judge how much they were willing to contribute to making this project happen.  In order to address this question we had S2o undertake an Economic Impact assessment.

We had a lot riding on the results of these studies and were being held to a very high standard.  The State commissioned a large and well known independent accounting firm to review our business model and market analysis prior to analyzing our grant application.  This accounting firm not only reviewed the numbers but applied several sensitivity tests to see how robust the business model was in the face of lower attendance or lower price point.  S2o’s Business model and market analysis passed with flying colors.  The accounting firm did not suggest a single revision.

The economic impact study did even more for our case.  Again, it was a well documented study based on actual user data from our region.  When the City’s economic team took it apart—checking the source data for content and validity and applying their own analysis to check our results—and came back with the same comments as the state:  “it looks good”.



The Instream Whitewater Park

Durango Whitewater Park
Durango Whitewater Park

My name is John Brennan and I’m the local coach here in Durango.  I’m also the guy that traditionally manages the club’s efforts to maintain our whitewater park.  Historically we did all of this work ourselves but we have been seeking out a way to get one of the experienced design teams involved in creating some specific play features.  In an effort to make this happen I have been working with the Animas River Task Force here in Durango to get buy-in as well as to get the design moved forward.

I know that Brian Brown has told you a little bit about how our process got started (link) so I wanted to focus on the design part of this process.  As Brian mentioned, we focused our design efforts on forming a task force that was filled with a variety of characters representing a number of different interest groups related to this project.  The task force included fishermen and environmental groups as well as rafters, kayakers, and members from the interested public.  The idea was to get input from each of these groups in order to move a project forward that benefited the most people.

Once we brought S2o on board as our whitewater design team we were pleasantly surprised to find that they were focusing their efforts on working with us.  Rather than presenting a design for us to approve or disapprove they included us in the process.  We were able to tour various sites along the river with their design team and give input into the things we liked and didn’t like.  We also worked with them to record the things that we found important—both good and bad—about how the park should look and act.  S2o then included us in the design process by articulating our “likes” and “dislikes” for the project and then providing a variety of design alternatives that best fit these objectives.  We worked with them to shape these many designs into one design that we all liked.  It was like we were able to watch the design take shape in front of us.  It was a process that made sense to us, as kayakers, and also to the other people in the room.  It was a design that we could all agree on.

The team also worked with local permitting people right from the start.  This helped our task force a lot because it allowed us to make informed decisions about the whitewater park.  Sometimes we would favor one site over another, or one type of wave over another, but S2o Design was able to tell us how that affected permitting requirements or water availability.  In the end we were able to be a part of a process that was not only attractive to our task force members, but something that they were able to get built within our budget.  This was a process that not only met our needs, but also moved the process quickly towards completion.


Insist on being a part of the process—the last thing you want is to have a designer drop a design on your table and tell you this is your best option.

Bring all the river users to the table through a committee or through public meetings.  You want everyone to take a stake in creating your whitewater park.

Pick a team that is not only knowledgeable, but that can work in front of a crowd.  Getting buy-in from our community has been one of our toughest hurdles and having a team that could helpus to educate and include our community has been a real benefit.

S2O Design Whitewater Park Featured in Riverbreak Magazine.

A Stand Up Paddle Boarder at the Durango Whitewater Park
A Stand Up Paddle Boarder at the Durango Whitewater Park

Check out this article that where the S2o whitewater park is featured in Riverbreak Magazine.  Here is an excerpt from the magazine:

2017 Animas River Days: River Surfing Comp

Durango is the place to be today! The surf comp “Animas River Days” (June 1-3) is the third stop in the Colorado Surf Circuit. Standup and shortboard river surfers are competing for cash prizes. The Ponderosa Wave is big and beefy, the surfing should be nothing short of exciting. Tune in to Surf Anywhere’s FB page at 12:45 Mountain Standard Time for the finals. Jacob Kelly will be covering the event live!

River Surfing at S2o’s Whitewater Park in Durango

Check out this great video of River Surfing at the Durango Whitewater Park.

SUP Durango Whitewater Park
Surfing Smelter Wave at the Durango Whitewater Parkof the Durango Whitewater Park during Animas River Days.

Shortboarding finals at Durango Colorado durning the Animas River Days. Competitors include: Miles Harvey, Michael Tavares, Brittany Parker, Erin Livingston, and more…

Posted by Surf Anywhere on Saturday, June 3, 2017


PRESS RELEASE: S2o is a Denver Area registered Small Business Engineering Firm

IMG_0293S2o is a Denver Area registered Small Business Engineering Firm, S2o Design and Engineering is proud to be a Denver area small business.  S2o Design is registered as a small business with the federal government under the Small Business Administration.  This is something that we have done because we are proud to employ people in the State of Colorado and United States.  S2o is proud of its team of award winning engineers, architects, and planners.

You may take it for granted that your company is a “small business.” The distinction is important if you wish to register for government contracting as a small business. To be a small business, you must adhere to industry size standards established by the U.S. Small Business Administration. As you register as a government contractor in the System for Award Management (SAM), you will also self-certify your business as small.

The SBA, for most industries, defines a “small business” either in terms of the average number of employees over the past 12 months, or average annual receipts over the past three years. In addition, SBA defines a U.S. small business as a concern that:

  • Is organized for profit
  • Has a place of business in the US
  • Operates primarily within the U.S. or makes a significant contribution to the U.S. economy through payment of taxes or use of American products, materials or labor
  • Is independently owned and operated
  • Is not dominant in its field on a national basis

The business may be a sole proprietorship, partnership, corporation, or any other legal form. In determining what constitutes a small business, the definition will vary to reflect industry differences, such as size standards.

Size Standards

Because all federal agencies must use SBA size standards for contracts identified as small business, you need to select NAICS codes that best describe your business and then determine if the business meets size standards for the selected NAICS codes. Use our Size Standards Tool to find out if you qualify as a small business. Once you have determined you are indeed a small business, you can then certify your business as small by registering as a government contractor.

Supply Irrigating Ditch Diversion Structure

fish passage, recreation
The supply ditch diversion combines fish passage and recreation into a single structure

During the September 2013 flooding every user of the St. Vrain Creek was impacted including agricultural, municipal, commercial, and recreational users. On top of impacts to the users of the St. Vrain the environmental impacts of the flood have been far reaching with the decimation of riparian habitat and severe impacts to the fishery. As the users reconstruct their critical infrastructure there is a new opportunity to create infrastructure that achieves the goals for the owner while also providing benefits for other users and the environment.

S2o is proud to be a part of this process and are implementing a design process that benefits all users and the environment in our projects. The diverse backgrounds of our team members bring expertise in whitewater park design, dam design, and river restoration design that shines in the design of multipurpose projects that benefit many interests. One example of a multipurpose project being implemented on the St. Vrain Creek is the Supply Irrigating Ditch Company diversion structure. Historically, the structure was an at grade concrete dam that was barely noticeable in the creek unless you looked close. During the flood significant erosion occurred downstream of the structure degrading the channel by up to three feet. S2o was hired by the ditch company to design a diversion dam that met their needs and benefited other users of the St. Varin Creek.

The ditch company used a temporary diversion structure for the 2014 irrigation season. The temporary structure was constructed of concrete barriers, concrete rubble, and anything else the ditch company could easily use to get water into their ditch. The temporary structure was not very effective at diverting water and was a significant hazard to any in stream user of the St. Vrain Creek. The hazards created by this temporary structure made the reconstruction of the diversion dam a high priority for safety as well as the ditch company’s need to divert water in 2015.

With this significant amount of degradation an at grade structure was not going to be possible for the rebuilt diversion structure. The first step in the design process was to determine the crest elevation of the structure. The crest elevation of the structure was dictated by the design criteria of being able to divert the allocated water down the ditch inlet. The necessary crest elevation combined with the degradation of the channel lead to an elevation drop of two feet across the structure. To create a structure that would address environmental concerns of fish passage and create a recreational experience a grouted rock ramp structure with a notch for fish passage at low flow was designed. Also, to facilitate fish passage the grouting of the structure will not go to the tops of the rocks allowing paths for fish to swim through the interstitial spaces in the structure. The hydraulic conditions across the grouted rock ramp and in the tail water pool were designed in the same manner as a whitewater park structure. This will allow the water that is not diverted down the ditch inlet to be enjoyed by recreational users. The designed structure will meet all of the project requirements by diverting the allocated water down the ditch, allowing fish passage, and providing recreational opportunities.

This project is a great example of a multipurpose structure that achieves the goals of the owner while also providing for other users. In this case the owner’s agricultural, municipal, and commercial interests are maintained with a structure that benefits recreational users and the environment.

Construction of the structure is scheduled to begin in the near future and the structure will be completed by May 1, 2015. Upon completion a highly visible structure will be in the forefront for multipurpose projects as the St. Vrain and other nearby watersheds recover from the 2013 floods. S2o is leading the way with well-coordinated multipurpose projects.

diversion recreation fish passage
The diversion structure also creates a fun surfing and tubing wave.

River Restoration and Resiliency Post-Flood

river restoration, fish habitat
St. Vrain Stream Restoration Project

River restoration is a challenge–particularly in an urban environment where the river is highly impacted and the river banks are often highly developed.  Project goals and objectives must be carefully stated and  project  constraints and limitations must be carefully defined and evaluated.  S2o has begun work on a $2.5 million restoration of the St. Vrain river following the worst flood in recorded history for this valley.  The starting point of this project is the most developed, confined, and, from a design standpoint, challenging, reaches in the river.  The goal of the project?  To minimize flood impacts and increase resiliency in the river by recreating a healthy river- and eco-system.

What is a healthy river and eco-system:  one good way to understand what a healthy, resilient river looks like is to understand what a typical unhealthy river looks like.  Fortunately, we have, or had, this type of area in Town located downstream of the 5th Avenue Bridge on the North Fork of the St. Vrain.  This area was a great example of a typical urban and highly impacted river before the flood.  In this area human development has severely encroached on the river to the point where all of the flow is confined between two steep banks.  This was done by landowners literally filling the floodplain with earth to build houses and streets that were positioned right along both sides of the main channel with very little breadth left for expansion during a flood event.  In order to handle moderate flooding events the people who built on both sides of the river built higher walls with fill at higher elevations so that more water translated to more depth.  This higher depth translated to higher velocities during flood events, and a channel that was largely denuded of habitat or complexity due to scour and excavation.  The North St. Vrain in this reach had become a square-bottomed ditch.

By comparison, a healthier river is one in which the river is a complex system with a defined low-flow channel, a defined river channel, some sinuosity, and room to expand into a floodplain.  The floodplain is a riparian area that typically includes a wealth of native trees and plants on a low bench near the river.  As the river rises, energy is diffused into this area which is important.  There are also a variety of species that thrive in this ecosystem and rely on regular flooding.  Each of these components plays a role in healthy river function.

In the area downstream of 5th avenue, which is an area that can be viewed in the coming weeks as it is developed.  You will see that  S2o has designed just such a multistage river and are building it now.  In this instance the multi-stage river is wedged within a fairly tight space yet it will provide each of these components.  The process of designing and implementing this project included:

  1. a) An evaluation of the watershed at varying reach scales to define priorities and objectives for this particular reach within the context of the entire river system.
  2. b) A conceptual design process in which varying solutions to meet these objectives were defined and evaluated until an acceptable design was reached (this process included a phase of public process which all of the town was invited to and invited to pose both questions and comments).
  3. c) A computer modeling phase in which extensive floodplain modeling was completed to ensure that no one’s home or property was negatively impacted by the project and that velocities and depths met design objectives.
  4. d) Several stages of design including grading, wall plans, design of the river, design of the habitat, and planting plans.  As a part of this process the project received all required permits to verify that these plans met all the regulatory requirements for doing this work in a river in Colorado.

One of our concerns is about losing trees and riparian habitat along the river.  The design team took all care possible to preserve as much plant life as possible and is replanting extensively to replace and improve the trees and riparian habitat lost.  The good and bad news is that, over the last 50-100 years, the confined and unhealthy river has still seen tree growth and riparian growth along its banks.  Many of these trees and plants are rooted in the same fill used to encroach upon the river years ago.  In order to remove this fill and open the river up to create a healthy river system, these trees and plants need to be removed. Without this, we make only band-aid improvements that do not protect the Town nor improve stream health. We will replant native trees (over 10,000 trees or plants are being planted) as part of this project, once a healthy river system has been re-created.  Please know that tree removal is not done lightly, but that extensive survey, design, computer modeling, and analysis was been completed prior to making these choices.  Additionally, an arborist has been consulted when in doubt about individual trees and choices are then made based on this information.

Additionally, S2o has worked with consultants to implement fish habitat in microsystems along the river.  The larger pool/riffle sequence has been further modified with imported boulders and superficial grading to create pools, riffles and velocity barriers in the river.  S2o has also added woody debris and classic fish habitat structures such as bendway weirs, j-hooks, cross-veins, and deflectors to further increase the habitat functionality of the project.

The completed river will have less flood risk, be more resilient, will decrease velocities and stress on the river, and will provide a thriving eco-system for both in-stream and riparian habitat.  This is a project that meets and exceeds the goals laid out in Lyons Long Range Recovery Process and one that provides us with a Town that will better endure the next flood.