Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
CHAPTER 4 STATE DOT AND AGENCY SURVEY SURVEY DESIGN The project research team developed and formatted a sur- vey form (questionnaire) that was sent to state DOTs and some other representative agencies that regulate highway projects. The project team anticipated that the agency sur- veys would uncover some new technology and monitoring data related to engineering performance, cost effectiveness, and environmental results. Copies of this initial survey were mailed out in July of 2001. Based on the findings and limita- tions of the first survey, a second survey was developed and mailed out in April 2002. SURVEY RESPONSE AND FINDINGS Initial Survey Twenty-six state DOTs responded to the initial survey. The most common problems or concerns with environmental techniques were: (1) limited experience designing, installing, and monitoring a new or modified technique; (2) lack of long- term, postconstruction data; (3) lack of hydraulic guidelines; and (4) general concerns about vegetation failure if not well established before high-flow events. The most common tech- niques employed were geotextile fabrics and variations on revegetation techniques. Following the return of the initial survey, agencies and subcontractors with the most experience were contacted for additional information. Useful data were received for rock vanes, vanes with j-hooks, boulder clusters, vegetated riprap, and vortex weirs. Follow-Up Survey The project team sent out a second survey to collect more comprehensive and informative responses. These revised surveys asked agency personnel to provide better site and reach descriptions and more quantitative information about reach hydrology and characteristics. Responses to the second survey were informative; however, there were still problems with the quantity and quality of the answers. Responses were received from a total of 29 states; there were 26 responses to the first survey, 22 responses to the sec- 10 ond survey, and 3 general responses. Many states responded to both surveys. Several respondents noted that they were not able to provide comprehensive responses to the question- naires because they lacked completion reports, monitoring data, and time to complete the survey. The largest impediment to survey responses was lack of time for DOT employees to fill out the surveys or provide information. In one case, the responder made a new box next to each question, labeled it âUnknown,â and then proceeded to check it. Another employee stated on the survey form that he had a large amount of information about the different techniques that his agency employed; however, when the employee was asked to send the information, he stated that he could not do this, as he did not have any spare time. This problem was completely understandable; however, it severely limited the amount of obtainable information and consequently the ability to compare techniques over a vari- ety of conditions. The second largest impediment was the lack of monitor- ing data. Resources to support monitoring are scarce, and monitoring is often not included in project budgets. Without monitoring, it is hard to make conclusions about hydraulic or geotechnical performance, the survival of vegetation, and so forth. Another difficulty was compiling comprehensive data since individuals seemed hesitant to report failures, even though failures may yield valuable information. Another obstacle experienced in obtaining information was that environmentally sensitive streambank stabilization tech- niques are usually passed over in favor of more traditional methods. Survey responses and follow-up correspondence suggested that the environmentally sensitive techniques are not used often due to lack of data. This creates a âchicken and the eggâ problem. There is very little information on these techniques because use is infrequent, and use is infrequent because there is very little information on the techniques. On the plus side, however, several states were able to provide quality information. A lack of knowledge on the part of the designers, con- struction contractors, and crew was identified as a factor in project failure. The impression was that managers and plan- ners get training and read manuals about techniques, but the people who are actually designing, specifying, and installing the measures have received no training. One respondent who did not attribute failures to lack of knowledge on the part of the designers mentioned that âlandscape architects came in
after the project was complete to vegetate it,â perhaps indi- cating a lack of integration among project components. These types of human problems evidently reduce success rates for environmentally sensitive/biotechnical projects. The survey results show a major emphasis on application of these measures to creeks as opposed to rivers. In the 21 states that have used the techniques, well over 250 projects were done on channels referred to as streams or creeks, while only 50 projects were reported on channels with names that include the word river. Although the use of these terms varies regionally, streams and creeks usually refer to smaller chan- 11 nels than rivers. Significantly, although one-third of the respondents reported recurring problems with the tech- niques, not one state reported completely unsatisfactory per- formance of the measures. These trends were considered in preparing the technique guidelines. For example, the importance of incorporating plant materials during construction, as opposed to planting after traditional protection measures are placed, is stressed. In addition, because there is such a bias toward projects in streams and creeks, this report focuses on issues associated with smaller channels.
