The San Miguel Watershed Coalition (SMWC) is nearing completion of a hydrologic tool for the San Miguel River watershed that can be used to quantify water availability under a changing climate, simulate hydrologic response to wildfire, evaluate the effectiveness of conservation efforts, and simulate other water management actions. The current U.S. Drought Monitor lists the San Miguel watershed as being in severe (D2) and extreme (D3) drought. Communities along the river want to protect water resources across all sectors to preserve the economic and environmental well-being of the basin. Existing tools do not provide the groundwater and climate-driven surface water dynamics needed to improve our understanding of ecohydrologic interactions and watershed resilience. The code used to create the model, MIKE SHE, is a fully integrated groundwater-surface water-climate modeling program that simulates the complex stream-groundwater interactions are needed to predict how realistic future changes in land use and climate will impact the system.

This living hydrologic tool will be housed locally by a nonprofit, and will allow stakeholders to evaluate the viability of proposed innovative solutions that balance water demands across agriculture, municipal, industrial, and environmental sectors, and will allow the community to plan for current and future water demands. A high-resolution sub-model of the Beaver Creek watershed has been created to evaluate the potential hydrologic impacts of wildfire. SMWC has also trained a graduate student on the model and hosted a two-day workshop on the model aimed at building the regional labor force and creating a water-fluent public. The level of interest in the project is high, based on the list of projects requested to be run after the model is completed, including drought and post-fire planning, water quality evaluations, floodplain restoration, and creative agreements to protect fish.

Adrian Bergere

Adrian is the Executive Director of the San Miguel Watershed Coalition. Adrian moved to Telluride in 2016 and got his feet wet working in the San Miguel as a fly fishing guide. In 2019 Adrian started working for the Coalition, focusing on research and GIS. After COVID, he stepped into the director role and has become a community leader in watershed issues, increasing the scope of the Coalition's work to include major restoration projects, while continuing the long-standing water quality program. Community stakeholders developed trust in Adrian's leadership through his participation in the San Miguel Stream Management Plan. Adrian is a member of the Southwest Basins Roundtable where he serves on the Interbasin Compact Committee.

Ann Maest

Ann Maest is an aqueous geochemist with Buka Environmental in Telluride, Colorado, USA. She specializes in the environmental effects of hardrock mining, baseline water quality, geochemical testing methods and modeling, and responsible mining assessment. Dr. Maest was a research geochemist at the U.S. Geological Survey, has served on several U.S. National Academy of Sciences earth resources committees and boards, and was an invited speaker on mining issues at the United Nations. She serves on several nonprofit boards, including the San Miguel Watershed Coalition in Colorado. Ann holds a PhD in geochemistry and water resources from Princeton University.

Stephen Blake

Stephen Blake, M.S. P.E. is a principal water resources engineer with over 30 years of experience in water resources management, environmental hydrology and hydraulics, drainage and stormwater and water quality management, environmental restoration planning and design, and the control and mitigation of environmental impacts, sediment management and water quality.  His responsibilities include the management of teams responsible for data analysis and processing for water-focused modeling and decision support, generally including custom development and digital delivery of modeling systems, impact analysis and forecasting. His education and project experience have included extensive work in coastal and estuarine, groundwater and integrated hydrological analyses from mountain and piedmont environments to large riverine floodplains and lakes to freshwater wetlands and coastal estuaries. He has worked with DHI (12 years), and several respected technical organizations, delivering interdisciplinary water and environment focused projects throughout the U.S., including the Florida Everglades, Rocky Mountains, Sierra Nevada and coastal California, as well as significant international work.

This presentation will describe the Mile High Flood District’s (MHFD) approach to answering this question: How much room does an urban stream need? Stream Management Corridors (SMCs) have been defined throughout MHFD’s service area to protect and preserve urban stream corridors while also identifying an overall width that accounts for MHFD’s five elements of urban stream function (hydrology, hydraulics, geomorphology, vegetation, and community values). These corridors prevent development from encroaching into the broad floodplain thereby allowing natural geomorphic processes to shape streams in urbanized settings. MHFD originally developed SMCs for all streams in the District’s service area with watersheds greater than 130 acres using a threshold planning approach based on each stream’s shear stress and an automated GIS analysis. However, MHFD identified areas within their service area where the shear force-based approach resulted in unrealistic SMC widths. A working group, convened by MHFD to review the shear force-based method, evaluated alternative methods, and recommended a path forward. The presentation will discuss the technical outcomes of working group’s evaluation, including selecting a regression-based analysis using widths from topographically derived valley bottoms and contributing drainage basin areas. To delineate an equation to map continuous SMC width based on upstream drainage area, we generated nonlinear (power law) regression equations between these variables: upstream drainage area values were provided by the MHFD stream network, and associated widths were provided by the valley bottom extraction tool (VBET) dataset. The nonlinear regression equations were used to calculate and plot widths in GIS as a continuous function of drainage area in acres. MHFD will provide these planning-level SMCs on their GIS mapping platform for local communities to help guide planning and design decisions.

Alluvial fans are part of a continuum of features that can be present within a watershed and are found consistently across Colorado. Colorado has implemented fluvial hazard assessment methods that recognize alluvial fans as part of a broad array of hazardous features to consider within riverine corridors. Recently, numerous states and counties have mapped or are actively mapping alluvial fans. The contemporary appreciation of alluvial fans as part of the spectrum of geohazards places greater impetus on identifying, assessing processes, and understanding the associated flood hazards present in these features. While this may appear to be rather straightforward, alluvial fans are complex features resulting from physical processes operating in the watershed, external factors (climate, tectonics, etc.) impacting the broader environmental context, and internal controls within the alluvial fan that often play a significant role in the flood hazards. These items and others have been consistently and increasingly studied by the scientific community over the past 50 years. Here, we present the current state of knowledge on watershed and alluvial fan relationships, surficial patterns and topographic controls, alluvial fan stratigraphy and its relation to alluvial fan evolution, external and internal controls on alluvial fan development, and the role of humans on modifying the processes operating on alluvial fans. This is done through a lens of properly identifying and assessing the alluvial fan processes and hazards with the goal of promoting more informed decision making at state, county, and local levels.

Thad Wasklewicz

Thad is part of a team growing Stantec’s Geohazards offerings. He is a geohazard specialist and geomorphologist. Thad has produced 55+ peer-reviewed articles and book chapters and provided 130+ conference and invited presentations. His geomorphic expertise is in debris flows, fluvial geomorphology, alluvial fans, and hillslope-channel coupling. He’s a past recipient of the National Science Foundation Early CAREER Award, past president of the Geological Society of America’s Environmental and Engineering Geology Division, served on multiple national and state review panels, a past scientist in residence at the USGS Landslide Hazard Program, and twice a visiting scholar at the University of Tokyo.