Last week our construction staff attended a preconstruction conference for what we consider a large stream restoration project that we are constructing. At the meeting, one of the project sponsors seemed almost gleeful that this project was in fact one of the most expensive stream restoration projects ever for them. The design and construction costs approached $1,000 per linear foot. You don’t have to be an expert in stream restoration or construction methods to conclude that this type of project is clearly not sustainable. I was curious how this project ended up being so expensive. To figure this out, I constructed a catalog of the material required to build the project. What jumped out at me was the 20,000 tons (not a typo) of furnished rock and gravel required to meet the spec, that was hauled over 150 miles round trip in many cases. As I continued the investigation I noticed that the salvage items in the bid were nonexistent, the limit of disturbance (LOD) made construction extremely difficult, and the list goes on and on. Clearly this project has wandered off the sustainability reservation.
How do we avoid designing stream restoration projects that are not sustainable, i.e., cost too much? Here are four principles to think about when you are in the early stages of a restoration project’s development.
- Material Source Locations – If materials are required, such as stream bed material, verify they can be obtained on-site or locally. For example, salvaged streambed material could be used in lieu of furnished streambed material. This can be easily accomplished by including a salvaged bid item in the project’s specifications and bid documents.
- Function over Aesthetics – We see quite a bit of “boutique” materials specified in project documents, such as sandstone boulders or rounded large cobble with very specific color requirements. In most cases the function of these “off brand” rock materials do not provide any measurable benefit, structurally or ecologically, to the project, but can certainly increase the project’s cost significantly.
- Use Vegetation – Vegetation and bioengineering is often an afterthought for streambank stabilization measures. Vegetation and its rooting structure become more rigorous over time while rock is only as stable as the first day it was placed on the site. Also, the success of the rock depends on the condition of the material where it was placed. Instead of a standard imbricated rock wall, a sustainable alternative might be a lower profile stone wall with a bench that has soil lifts constructed above the stone. Then, add some brush layering within the lifts and you have a sustainable alternative.
- Balance Cut and Fill – This is one of the easiest ways to save your project money and reduce hauling costs. Leave ample room within the LOD in the project’s sediment and erosion control plans to place spoil materials. Balancing your cut and fill at the concept design stage is the perfect time to nail this down. After that, it may too late to realize this cost saving measure. When material has to be hauled off site, the costs to move that material will easily triple cost of disposing of the excess material.
By integrating these four components into the design process, you can dramatically increase the cost effectiveness of your project. If you want to take it to the next level, try bringing on ecological contractors to your team and allow them to participate in the design development or contract projects through a design-build scenario.
Stream restoration is often featured as a major component of many jurisdictions’ websites and their sustainability programs. More recently, it has become a popular Best Management Practice (BMP) for jurisdictions to meet EPA mandated total maximum daily load (TMDL) goals. It is increasingly important for project sponsors to “look under the hood” at these projects. This means the sponsor should assess methods and associated costs and develop more sustainable approaches while still providing integrity of design and ecological uplift. The political viability of stream restoration as an accepted and beneficial practice depends on better checks and balances, a sustainable approach, and common sense to realize cost savings as well as better restoration projects.
Do you agree? Does the cost of stream restoration design and construction matter to your organization?
Scott McGill, co-founder and principal at Ecotone, Inc., received a B.S. in Natural Resource Management from the University of Maryland, College Park in 1989. His 23 year career has focused on the assessment, design, construction and monitoring of stream, wetland, riparian restoration projects throughout the East Coast. In 1998 he co-founded Ecotone, Inc., a river and wetland restoration company headquartered in Forest Hill, Maryland. Originally established as a design firm, in 2003 Ecotone expanded its operations to include restoration construction and adaptive management, specializing in vertically integrated ecological design/build projects. Utilizing the design build process, Ecotone strives to integrate sustainable principles into its design and construction methods and strategies. In 2005, he co-founded Albemarle Restorations, LLC, a North Carolina based company which focuses on large scale restoration of coastal plain wetlands and streams. His firms have designed and/or constructed over 14 miles of stream restoration work and 700 acres of wetlands in the Mid-Atlantic and Southeastern regions of the U.S. Scott may be reached at smcgill@ecotoneinc.com.
