A widely used approach for describing the form of streams and rivers is a method called the Rosgen Stream Classification System. Developed by Colorado hydrologist Dave Rosgen, and taught through short courses, the system provides a simple way of classifying stream types based on a few key measurements. Streams are assigned a capital letter and number combination such as “C-3” to describe key characteristics in a kind of shorthand language.
Most discrepancies could be attributed to measurements performed for the calculation of a characteristic called the “entrenchment ratio.” Entrenchment is a measure of the vertical confinement (bank height) of the stream. The entrenchment ratio is determined by dividing the width of the flood prone area by the bankfull width. These differences were likely due to discrepancies in another measurement called “maximum bankfull depth.” Bankfull depth means the average vertical distance between the channel bed and the estimated water surface elevation required to completely fill the channel to a point above which water would enter the floodplain or intersect a terrace or hillslope. The differences in the assessment of this value, described as “inherently uncertain” by the study authors, often resulted in different determination of primary stream types.
Despite the classification system’s widespread use and popularity, studies like this one are clearly showing that the measurements the system relies upon are ambiguous, and can cause highly variable results within the same streams among different practitioners. These types of findings continue to call into question the adequacy of the Rosgen system in objectively characterizing stream morphology.
For a stream scientist Tropical Storm Irene, which dumped loads of rain on Northeast, provided what one researcher calls a “grand experiment” — the opportunity to investigate what happens when a stream system faces a major disturbance.
In Vermont, where Dartmouth College scientists are studying the aftermath, the storm knocked out hundreds of roads and bridges in the state, damaged or destroyed more than 700 homes and left some towns stranded. Flooding moved whole sections of rivers and streams, gouging out roads and farm fields. In some cases, huge piles of gravel were deposited in other locations.
“Irene was a wakeup call,” said Dartmouth geography professor Frank Magiligan. Magiligan and others are assessing streams in order to pinpoint potential trouble spots that can aid scientifically-informed planning decisions. But recovery and repair efforts are concerning to some scientists, who say efforts to “repair and restore” streams with bulldozers and other heavy equipment actually “did more damage that the storm.”
Nutrient pollution is one of the nation’s most widespread and costly environmental problems. Excess nitrogen and phosphorus from farm and lawn fertilizer, livestock waste, roads and houses, faulty septic systems, and treated sewage can turn waters green with slime and pollute waters for swimming, boating, and fishing. To help raise awareness about this growing environmental problem, EPA created a short video to illustrate the potential impacts of nutrient pollution. See Video> http://www.youtube.com/watch?v=vCicSNnKUvM
Healthy, functioning floodplains, combined with efforts to reduce point source and non point source pollutants, are key to improving water quality. Trout Headwaters, Inc works to restore and protect floodplains and healthy riparian vegetation zones in order to filter and absorb excess nutrients before they enter our waterways.
Decreased snowpack in the Rocky Mountains may compound problems for Colorado, Arizona, California, and other Western states.
On April 10th, 61 percent of the lower 48 states were listed by the U.S. Drought Monitor to be in abnormally dry or drought conditions. To assess the vulnerabilities of the watershed and consider how water supply and demand might change in the coming years, the U.S. Department of the Interior’s Bureau of Reclamation has embarked on a study of theColoradoRiver Basin to be released this July.
“Existing demand very clearly outstrips existing supply,” says Barry Nelson, a senior policy analyst in the water program at the environmental nonprofit Natural Resources Defense Council (NRDC). “That’s the main reason we’re seeing declining storage. That simply cannot continue.”
We note the draft language in Montana DNRC’s 2012 Model Floodplain Ordinance requiring that “a licensed professional engineer” (P.E.) design all stream restoration and bank stabilization projects undertaken in Montana. While engineering is an important professional discipline, the proposed rule as written would greatly diminish the vital roles played by hydrologists, fluvial geomorphologists, sedimentologists, ecologists, and the other skilled scientists in this important work. Further, it’s very important to understand that there is no consistent requirement in a professional engineer’s academic training or in Montana’s P.E. certification criteria that would dictate the attainment of specific skills for stream bank stabilization and restoration.
Decades of misguided, hard-engineering attempts to force natural stream systems into unnatural configurations have resulted in unhealthy, armored floodplains along many of our nation’s streams, including in Montana. History will likely describe our time as a period of human failure – the failure to understand and the failure to accommodate the most basic ecological needs and functions of our precious water resources. These waters and their floodplains serve a broad host of ecological services for humans and wildlife, providing biodiversity, aquifer recharge and carbon sequestration. Without the protection of these basic functions, we will pass to the next generation a tarnished legacy of damaged and destroyed resources.
Any successful stream restoration or bank stabilization project requires a multi-disciplinary or inter-disciplinary team of scientists and technicians to ensure success. THI would suggest that granting a design monopoly for stream bank stabilization and river restoration to engineers may simply expose many P.E.’s to increased liability due to a general lack of direct experience in these applications.
Anyone interested in the future of Montana’s Floodplains, Rivers and Wetlands should comment on Montana DNRC’s 2012 Model Floodplain Ordinance now: Traci Sears phone: 406-444‐6654, or via email at email@example.com
As warmer temperatures thaw winter’s blanket of snow and ice, the runoff enters lakes, rivers and streams, carrying with it a winter’s-worth of de-icing compounds. Despite making roads safer, salt and deicers are still peppered with danger. Between 10 and 20 million tons of salt are applied to roadways every year. These liberally-applied agents are linked to a diverse array of environmental ills, from aquatic “dead zones” and salt-damaged plants, to poisoned amphibians, and possibly even increased cancer risk in humans.
Besides the impacts of increased salinity, unrefined road salt can contain impurities that aren’t found in its tabletop cousin. It can contain various metals and minerals, and often chemical additives like sodium ferrocyanide, an anti-caking agent. And even pure salt isn’t exactly eco-friendly, since it raises the salinity of local water supplies, potentially making them toxic to native fish and wildlife.
At Trout Headwaterswe put a lot of emphasis on stream and wetland assessment. Our unwavering belief in scientifically-sound assessments of water resources led us to develop a patented system just for assessments called RiverWorks Rapid Assessment System®. Because of the number of stream restoration failures we’ve seen in the last 16 years, we have been vocal opponents of popular cookbook stream classification systems that shortcut the stream assessment and restoration design process.
In 2005 the American Society of Civil Engineers published an article by several prominent scientists which evaluated the Rosgen method of stream classification and natural channel design. The 2005 article opens with, “Over the past 10 years the Rosgen classification system and its associated methods of ‘natural channel design’ have become synonymous (to many without prior knowledge of the field) with the term ‘stream restoration’ and the science of fluvial geomorphology.”
The article concludes with, “Empirical approaches such as those inherent in “natural channel design” … do not provide cause and effect solutions or means of predicting stable channel dimensions and represent only one possible alternative to evaluating stream channels.” And, “Practitioners concerned with professional liability and with the future of their professions would do well to provide design services based on peer-reviewed professional standards.”
Classification systems and channel evolution models (CEM) are no substitute for proven, thorough assessment techniques, including the use of upstream and downstream reference reaches. Our freshwater resources are far too important to shortcut. Rosgen_Classification_Problems
Fishing guides float and fish our nation’s rivers every day. Because of their familiarity and concern for the resources they fish, guides are often able to spot early problems with stream and river health. It’s unfortunate that a notable number of poorly designed stream restoration projects can actually cause greater harm to an already compromised resource.
The Trinity River Guides Association and the California Water Impact Network have expressed concerns that restoration projects may be causing harm to the river. The two organizations have asked the Trinity River Restoration Program to take a break to determine if river restoration projects completed to date have met their objectives or had unintended impacts. The letter points to excessive gravel introduction into the river channel as well as numerous side channel failures.
The Marcellus shale formation stretches through a wide swath of the Chesapeake Bay Watershed, underlying large parts of the states of New York, Pennsylvania, Maryland, West Virginia and Virginia. Energy extractors have been planning large-scale natural gas “fracturing” operations for the past decade. State environmental regulators are attempting to understand the process and impacts of these operations. The permitting processes, to date, have been catch-as-catch-can in many instances. At least in Pennsylvania, that is about to change, thanks to a recent court ruling on behalf of the Chesapeake Bay Foundation (CBF).
The obvious impacts of shale fracturing are the above ground pipelines, drilling and staging areas. The not-so-obvious impacts are those on the ground water in the adjacent aquifers. The Pennsylvania Department of Environmental Protection, charged CBF, neglected the needed protections in favor of a streamlined process that would make it easier and faster for drilling operations to move forward in Pennsylvania. Trout Headwaters is pleased to see that the CBF is actively monitoring these developments. A recent finding by a Pennsylvania court as summarized in a recent CBF press release, found at (www.cbf.org/page.aspx?pid=2561)
The lessons learned in Texas, and other more mature “fracture” shale fields of exploration, demonstrate that careful analysis, monitoring and mitigation are essential throughout the lifetime of these extraction activities. CBF’s oversight and actions to ensure such compliance should be commended.
Kudos are deserved for the North Carolina legislature for recently passing legislation (which Governor Perdue signed) addressing an issue that has plagued the stream and wetland restoration efforts for years: insufficient project assessment, design and monitoring. Fifteen years ago, Trout Headwaters, Inc (THI) entered the stream restoration industry, and unfortunately, a significant amount of our work today is “re-restoring” streams and wetlands due to failed designs and approaches.
The April 17 Charlotte Observer article (North Carolina spends $140 million on faulty water projects by Dan Kane and David Raynor) aptly highlights many of the problems that plague the still-emerging aquatic restoration industry. When funding escalates for a particular restoration action, money or politics may seek to “replace” sound science. In North Carolina, DOT mitigation became a very lucrative opportunity. One clear problem with failed stream and river restoration projects has been the rampant use of a formulaic or “cookbook” approach currently being used across the United States, and certainly in North Carolina. Unfortunately, this unreliable recipe has been responsible for many spectacular and expensive failures.
As one of the old guys in this relatively new industry of stream restoration we’ve been preaching for more than a decade against simplistic cookbook approaches to complex ecological problems, and have pleaded the case for better industry standards when it comes to assessment and monitoring. We have watched the growing debate over the uncertainty associated with restoration (and especially with aggressive, formula-based approaches) now reaching a broader public consciousness.
We urge North Carolina and the U.S. Army Corps of Engineers to take a closer look at what works, and what doesn’t in stream restoration methodologies and approaches. Peter Raabe from American Rivers, an environmental watch group, summarized recently: “Giving more work to the people who are the absolute experts in the ﬁeld is probably the direction we should be going.”
THI agrees and is supportive of this state’s efforts to steer the industry in a sustainable direction.