Browsing by Author "Wilson, Bruce N."

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Assessment of Stormwater Best Management Practices
(University of Minnesota, 2008-04) Anderson, James L.; Asleson, Brooke C.; Baker, Lawrence A.; Erickson, Andrew J.; Gulliver, John S.; Hozalski, Raymond M.; Mohseni, Omid; Nieber, John L.; Riter, Trent; Weiss, Peter; Wilson, Bruce N.; Wilson, Matt A.; Gulliver, John S.; Anderson, James L.
Characteristics of Erosion Control Measures and Their Impact on Erosion
(2002-06-01) Singh, Udai; Thompson, Anita; Wilson, Bruce N.; Nguyen, Hung; Subramaniam, V K
This project endeavored to expand experimental data on erosion control blankets and develop greater understanding of how blankets and erosion principles interact. Blankets that are effective in reducing raindrop impact may become ineffective in controlling soil detachment and runoff (rill erosion) on longer slopes. This field study of erosion control products under artificial rainfall conditions was conducted at the Highway 10 overpass in Coon Rapids, Minnesota. Examining long slope lengths (60 feet and 100 feet), bare soil erosion was compared to erosion under straw blankets, wood fiber blankets, straw mulch, and sprayed emulsion. Measurements of runoff, erosion, and biomass (vegetative growth) were made in spring and fall under wet and dry conditions. Sediment loads for bare soil were 8 times larger than other treatments. Sediment loads were substantially smaller for the fall runs than the spring runs, largely due to the substantially increased vegetative cover (biomass). Shear stress partitioning for erosion control blankets was evaluated using a laboratory flume and hot-film anemometry. Erosion control blankets partition shear stress into form shear (the portion that acts on the blanket) and particle shear (the portion that acts on the soil particles). Blanket type, flow conditions, and fastener impacts were considered. Shear partitioning was found to be an important process in design and erosion modeling. Attempts were made to correlate sediment load and vegetative density data gathered by Texas Department of Transportation (TxDOT) with manufacturer's information on blanket characteristics. However, the data from manufacturers was insufficient to determine patterns or predict performance. Keywords-erosion control products, vegetation establishment, soil erosion, slope hydrology
Climate Change Adaptation of Urban Stormwater Infrastructure
(Minnesota Department of Transportation, 2023-06) Erickson, Andrew J.; Herb, William R.; Gallagher, Noah D.; Weiss, Peter T.; Wilson, Bruce N.; Gulliver, John S.
The final analysis of historical (TP-40), current (Atlas 14), and future predicted storm events for three watersheds in Minnesota (Duluth, Minneapolis, Rochester) has shown that current design philosophy is not sufficient to prevent flooding from 10-year and larger design storm events and that flood depth and duration will increase given current climate projections. Several stormwater infrastructure adaptation strategies were assessed for reducing flood depth and duration: Baseline (existing conditions), adding rain gardens (aka, Infiltration Basins), adding new wet ponds, retrofitting existing stormwater ponds to be ?Smart Ponds, adding new Smart Ponds while also converting existing ponds into Smart Ponds, or upsizing of stormwater pipes to convey more water. In watersheds that are mixed urban, suburban, and rural like Rochester?s Kings Run or Duluth?s Miller Creek sub-watersheds, the most cost-effective climate change adaptation strategy was to build new stormwater wet ponds (Extra Ponds strategy) to treat the impervious surfaces not currently treated by existing wet ponds and other stormwater BMPs. In the fully developed urban 1NE watershed in Minneapolis, the most cost-effective (excluding land costs) climate change adaptation strategy was building wet ponds (Extra Ponds). Securing property for building new stormwater infrastructure in fully developed urban watersheds like 1NE may be a substantial cost compared to other watersheds. Smart Ponds do not require additional land for implementation and thus represent a relatively low-cost alternative that will be more beneficial in watersheds with numerous existing wet ponds.
Design Tool for Controlling Runoff and Sediment from Highway Construction
(Minnesota Department of Transportation, 2008-08) Wilson, Bruce N.; Sheshukov, Aleksey; Mendez, Aida
Regulations require that stormwater pollution prevention plans be developed for construction activities that disturb an area that is equal to or greater than one acre. Different strategies, including a combination of practices, can be used to develop these plans. The WATER model was a tool developed from a previous project to assess the effectiveness of different on-site sediment control practices. This model is expanded in this study to consider offsite practices, to include processes at the watershed scale, and to allow spatial data sets to be integrated into the simulation framework. Routines to simulate the impact of off-site practices of rock check dams, vegetative filters, and detention ponds are added to the WATER model. The detention pond model has been modified to allow rock and gravel infiltration filters to be included as an off-site practice. Two different algorithms are used: (1) the Protocol Method based purely on empirical data and (2) the Process-Based Method using process-based relationships developed for porous media flow.
Determination of Effective Impervious Area in Urban Watersheds
(Center for Transportation Studies, University of Minnesota, 2015-07) Ebrahimian, Ali; Gulliver, John S.; Wilson, Bruce N.
Impervious surfaces have been identified as an indicator of the impacts of urbanization on water resources. The design of stormwater control measures is often performed using the total impervious area (TIA) in a watershed. Recent studies have shown that a better parameter for these designs is the “effective” impervious area (EIA), or the portion of total impervious area that is hydraulically connected to the storm sewer system. Methods to improve estimates of EIA are not highly researched, and need further investigation. The overall goal of this project is to develop a method to estimate EIA in urban watersheds with data that is readily available. First, the existing rainfall-runoff method was improved by reducing the uncertainty associated with EIA estimates and applying it to 40 gauged urban watersheds with different sizes and hydrologic conditions, mostly in the Twin Cities metro area of MN and Austin, TX. The results are then utilized to develop a new method based on the integration of GIS and Curve Number (CN). The GIS-CN method is applicable to un-gauged watersheds and is able to estimate EIA fraction based on TIA and hydrologic soil group (HSG). The results are used to evaluate the potential and the limitations of the GIS-CN method. The outcome and applications of this study improves the rainfall-runoff modelling in urban watersheds and will eventually lead to the design of a more sustainable urban stormwater infrastructure.
Development and Evaluation of Effective Turbidity Monitoring Methods for Construction Projects
(Minnesota Department of Transportation Research Services & Library, 2014-07) Perkins, Rebekah Lynn; Hansen, Brad; Wilson, Bruce N.; Gulliver, John S.
Various agencies have discussed the possibility of using turbidity as an effluent standard for construction site. Turbidity monitoring can be difficult for dynamic construction sites. This project investigated turbidity relationships for conditions of Minnesota and developed protocols for the design and installation of cost-effective monitoring systems. Turbidity characteristics of fourteen different soils in Minnesota were investigated using the laboratory protocols. Trends in turbidity with sediment concentrations were well represented by power functions. The exponent of these power functions was relatively constant between soils and the log-intercept, or scaling parameter varied substantially among the different soils. A regression analysis for the scaling parameter was a function of percent silt, interrill erodibility, and maximum abstraction. A power value of 7/5 was chosen to represent all soils. The field studies were also used to develop turbidity monitoring systems that would be adaptable to construction sites and to collect turbidity data on construction site runoff. Construction site turbidities often exceeded 1000 NTUs and sometimes surpassed 3000 NTUs.
Development of Techniques to Quantify Effective Impervious Cover
(St. Anthony Falls Laboratory, 2011-07) Janke, Ben; Gulliver, John S.; Wilson, Bruce N.
Practitioners responsible for the design and implementation of stormwater management practices rely heavily on estimates of impervious area in a watershed. However, the most important parameter in determining actual urban runoff is the ‘effective’ impervious area (EIA), or the portion of total impervious area that is directly connected to the storm sewer system. EIA, which is often considerably less than total impervious area and can vary with rainfall depth and intensity, is likely not determined with sufficient accuracy in current practice. A more accurate determination of EIA in a watershed would benefit a wide range of organizations involved in the design of stormwater management, pollution prevention, and transportation structures. This study investigated two existing methods of estimating EIA in a watershed: (1) analysis of large rainfall-runoff data sets using the method of Boyd et al. (1994), and (2) overlay analysis of spatial (GIS) data, including land cover, elevation, and stormwater infrastructure, using the method of Han and Burian (2009). The latter method provides an estimate of connected pavement, but requires the user to input the value of connected rooftop to determine the actual EIA value, which is the sum of these two quantities. The two methods were applied to two urban catchments within the Capitol Region Watershed in St. Paul, MN; one was a small (42-ac), relatively uniform residential neighborhood, and the other was a large (3400-ac), highly-urbanized catchment with a variety of land uses present. The results were used to evaluate the potential of each method and make recommendations for future studies. In summary, the data analysis technique (Boyd et al., 1994) has the advantage of being quick and relatively simple to implement, as it did not require familiarity with specialized software tools (e.g. ArcGIS) and could be completed with any spreadsheet program with graphing capabilities (e.g. Excel). The EIA estimates from the data analysis are the most accurate, but the technique is unable to determine where in the watershed the EIA is located, and cannot be used if runoff discharge and local precipitation data is unavailable. By contrast, the GIS method (Han and Burian, 2009) has the advantage of being applicable to un-gauged watersheds, and also provides the location of EIA in the watershed. This latter feature makes it particularly attractive for honing the development and placement of BMP’s in a watershed. Unfortunately, the accuracy of the GIS method is completely dependent on the ability to faithfully represent the amount of roof connection in a watershed, a process that can add significant time and expense to the EIA estimate.Future work should be focused primarily on two general areas: (1) improving the GIS-based estimation technique, and (2) expanding the application of both techniques to additional sub-watersheds, with particular emphasis on newer development and on catchments with more homogenous land uses. The GIS method could be improved considerably by developing techniques to improve roof connectivity estimates, e.g. through the use of land use-specific site surveys or through some novel partitioning scheme based on age or type of rooftop. An improved method for handling canopy shading of impervious surfaces than that used herein could also be investigated. Insight on both of these areas of improvement could be supplied by application of both the data analysis and the GIS-based techniques to additional watersheds. Furthermore, additional analyses could potentially allow EIA values to be correlated to land cover characteristics such as roof type, canopy shading, age of construction, lane-miles of road, BMP presence, etc. or even to rainfall characteristics such as intensity, duration, or antecedent rainfall depth. This type of generalized information would be valuable to practitioners in applications such as stormwater management, transportation design, or water quality protection.
Development of Techniques to Quantify Effective Impervious Cover
(Center for Transportation Studies, University of Minnesota, 2011-09) Janke, Ben; Gulliver, John S.; Wilson, Bruce N.
Practitioners responsible for the design and implementation of stormwater management practices rely heavily on estimates of impervious area in a watershed. However, the most important parameter in determining actual urban runoff is the "effective" impervious area (EIA), or the portion of total impervious area that is directly connected to the storm sewer system. EIA, which is often considerably less than total impervious area and can vary with rainfall depth and intensity, is likely not determined with sufficient accuracy in current practice. A more accurate determination of EIA in a watershed would benefit a wide range of organizations involved in the design of stormwater management, pollution prevention, and transportation structures. This study investigated two existing methods of estimating EIA in a watershed: (1) analysis of large rainfall-runoff data sets using the method of Boyd et al. (1994), and (2) overlay analysis of spatial (GIS) data, including land cover, elevation, and stormwater infrastructure, using the method of Han and Burian (2009). The latter method provides an estimate of connected pavement, but requires the user to input the value of connected rooftop to determine the actual EIA value, which is the sum of these two quantities. The two methods were applied to two urban catchments within the Capitol Region Watershed in St. Paul, MN. The results were used to evaluate the potential of each method and make recommendations for future studies. In summary, the data analysis technique (Boyd et al., 1994) has the advantage of being quick and relatively simple to implement, as it did not require familiarity with specialized software tools (e.g. ArcGIS) and could be completed with any spreadsheet program with graphing capabilities (e.g. Excel). The EIA estimates from the data analysis are the most accurate, but the technique is unable to determine where in the watershed the EIA is located, and cannot be used if runoff discharge and local precipitation data is unavailable. By contrast, the GIS method (Han and Burian, 2009) has the advantage of being applicable to un-gauged watersheds, and also provides the location of EIA in the watershed. This latter feature makes it particularly attractive for honing the development and placement of BMP?s in a watershed. Unfortunately, the accuracy of the GIS method is completely dependent on the ability to faithfully represent the amount of roof connection in a watershed, a process that can add significant time and expense to the EIA estimate.
Effective Impervious Area in Urban Stormwater Management
(2014) Ebrahimian, Ali; Gulliver, John S.; Wilson, Bruce N.
Efficacy of Erosion Control Blankets and Soil Stabilizers
(2000-05-01) Benik, Scott; Wilson, Bruce N.; Biesboer, David D.; Hansen, Brad
This report presents the results of a two-year field study on the performance of erosion control products under natural and artificial rainfall conditions. Vegetation, run-off, and erosion data were collected at a newly constructed roadway. Run-off and erosion data were gathered using natural rainfall events and using a rainulator to spray water onto the surface. Treatments included a wood fiber blanket, a straw/coconut blanket, a straw blanket, a bonded fiber matrix, and disk-anchored straw mulch for natural rainfall events. For the rainulator events, a bar soil treatment also was used. Biomass, percent cover, and species composition also were measured at the research site. Five run-off events from natural rainfall were measured and revealed very little difference in sediment production between the straw, straw/coconut, and the wood fiber blankets. These blankets had approximately one-tenth the erosion that was observed for the straw-mulch plots. The impact of the erosion control treatment was substantial for early season artificial events. The sediment loading rates from the blankets and bonded fiber matrix plots were roughly one hundred times smaller than the bare soil plots and 10 times smaller than the straw mulch plots. For late season events, the erosion from these products were approximately one-half of that from straw mulch treatments.
Erosion Risk Assessment Tool for Construction Sites
(2006-07-01) Wilson, Bruce N.; Sheshukov, Aleksey; Pulley, Reid
The impact of erosion and sediment from construction sites can be reduced by using a variety of onsite and offsite practices. The WATER model was developed to be a tool to assess the effectiveness of different sediment control practices. The WATER model evaluates risk by performing many simulations of a construction site response for different weather conditions. A particularly important component of the WATER model is the prediction of daily climate variables and storm characteristics called WINDS. This model uses the statistics for the analyzed data to predict many years of possible weather conditions. Predicted weather and storm characteristics are in very good agreement with those observed. The WATER model simulates surface runoff, plant processes, and erosion and sediment transport as major hillslope processes. Four runoff events (spring dry run, spring wet run, fall dry run, and fall wet run) from artificial rainfall conditions were measured.
The Impact of Roughness Elements on Reducing the Shear Stress Acting on Soil Particles
(2002-01-01) Thompson, Anita; Wilson, Bruce N.
This report presents the results from a study on shear stress partitioning for vegetation. The project involved partitioning the shear stress from overland flow into one component that acts on the vegetation (form shear) and the remainder that acts on the intervening soil particles (particle shear). Particle shear is important for predicting soil erosion. The study used idealized shapes to represent vegetal elements. Researchers designed and constructed a unique laboratory hydraulic flume, which they used in conjunction with hot-film anemometry to measure particle shear. They also designed and constructed instrumentation to measure the form shear on individual rigid vegetal elements, taking detailed spatial and temporal shear stress measurements for three element densities. Form shear was measured on each element within the test array. The study investigated a total of 16 test scenarios. Particle shear accounted for 13 to 89 percent of the total shear. Shear partitioning theories developed for wind erosion adequately represent the observed data and can be used to determine an appropriate vegetation density for a threshold particle shear. Keywords-vegetation, overland flow, erosion, shear stress partition, hot-film anemometry
Scoping Study for the Development of Design Guidelines for Bioengineering in the Upper Midwest
(St. Anthony Falls Laboratory, 2004-08) Mohseni, Omid; Weiss, Jeffrey D.; Cantelli, Alessandro; Wilson, Bruce N.
It has been about fifteen years since soil bioengineering and bioengineering technology have been used in projects to protect slopes and river banks against erosion in the U. S. Now many consulting firms as well as state and federal agencies promote and practice these techniques. Despite a widespread support of these techniques, many projects have failed. Therefore, it is deemed necessary to develop a set of design guidelines to ensure a higher rate of success. In order to develop design guidelines for soil bioengineering and bioengineering technology, a pilot study was conducted to determine the amount of work already done in these areas, and to define the existing research needs. This report comprises (a) a summary of literature review, (b) interviews with eleven practitioners in the field, (c) an evaluation of three projects done in Minnesota, (d) current research needs, (e) and a brief evaluation of three sites in the vicinity of the Twin Cities area as potential outdoor laboratories to conduct research in the needed areas. It also includes a summary of a site visit of the Department of Soil Bioengineering and Landscape Construction at the University of Agricultural Sciences in Vienna, Austria. The study shows that a significant number of studies have been done on topics related to soil bioengineering techniques. However, these studies mainly address the problems at a micro scale, and hence, there is a gap between existing knowledge and practice. Therefore, there is an urgent need to not only study some of the fundamental processes and mechanisms involved in soil bioengineering techniques, but also to investigate these processes at a macro scale to evaluate their strengths and impacts when applied to streambanks and slopes. Main highlights of the research needs identified in this study were a) quantifying the bank and bed roughness with the most common plants used in bioengineering techniques, b) studying the added shear strength to banks by vegetation, c) determining the resiliency of different plants under high flow conditions, e) understanding the mechanisms which cause failure of plants under different flow conditions, f) quantifying the shear strength of the commonly used techniques for a range of bank slopes, top soil depths and soil types, and g) determining the shear strength of composite systems, where different plants and techniques are combined. To conduct research in the needed areas three sites were identified and evaluated as potential outdoor research facilities in the vicinity of the Twin Cities area, Minnesota. The three candidate sites were (1) the two abandoned wasteways near the Falls of St. Anthony located adjacent to the St. Anthony Falls Laboratory, (2) a 7 acre area in the northern part of the UMore Park, a University of Minnesota property allocated for research, and (3) a short reach of the Vermillion River near Empire, MN, located on private property.
Scoping Study for the Development of Design Guidelines for Bioengineering in the Upper Midwest
(2004-08-01) Mohseni, Omid; Weiss, Jeffrey D.; Cantelli, Alessandro; Wilson, Bruce N.
It has been about fifteen years since soil bioengineering and bioengineering technology have been used in projects to protect slopes and river banks against erosion. Now many consulting firms as well as state and federal agencies promote and practice these techniques. Despite a widespread support of these techniques, many projects have failed. Therefore, it is deemed necessary to develop a set of design guidelines to ensure a higher rate of success. In order to develop design guidelines for soil bioengineering and bioengineering technology, a pilot study was conducted to determine the amount of work already done in these areas, and to define the existing research needs. This report comprises (a) a summary of literature review, (b) interviews with eleven practitioners in the field, (c) an evaluation of three projects done in Minnesota, (d) current research needs, (e) and a brief evaluation of three sites in the vicinity of the Twin Cities area as potential outdoor laboratories to conduct research in the needed areas. It also includes a summary of a site visit of the department of Soil Bioengineering and Landscape Construction at the University of Agricultural Sciences in Vienna, Austria. The study shows that a significant number of studies have been done on topics related to soil bioengineering techniques. However, these studies mainly address the problems at a micro scale, and hence, there is a gap between existing knowledge and practice. Therefore, there is an urgent need to not only study some of the fundamental processes and mechanisms involved in soil bioengineering techniques, but also to investigate these processes at a macro scale to evaluate their strengths and impacts when applied to streambanks and slopes.

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