25 Jul 2022

Engineering With Nature® in Fluvial Systems

Purpose: The purpose of this technical note is to underline the growing need for Engineering With Nature® (EWN) guidance for inland fluvial systems. In comparison to the EWN coastal initiatives, guidance, and technical publications, emphasis on inland fluvial systems has been primarily focused on larger river systems, rather than smaller and intermediate-sized tributary systems. As EWN continues to expand its offerings and support inland systems, there is a strong need to fill data gaps and offer case study examples from underrepresented issues across different hydro-physiographic regions and ecosystems. Accordingly, this technical note offers background on the growing need for riverine EWN guidance as well recommendations moving forward to help address those needs.

11 Mar 2022

Field Guide to Identifying the Upper Extent of Stream Channels

ABSTRACT: The upper extent of a channel is a transition zone from the hillslope to the beginning of the stream channel. Accurately and consistently identifying the upper extent of a channel in the field and locating where hillslope processes transition to stream-channel processes can be a difficult task. Physical characteristics located at the beginning of a channel (i.e., channel head), including geomorphic, sediment, and vegetation indicators, can vary significantly across different landscapes in the United States. Remote tools are useful for examining the upper extent of channels, but these remote tools have limitations for identifying the beginning of channels. Even as the resolution of remote data continues to increase, field observations are necessary to validate the remote data on the ground and to accurately and consistently identify and locate the transition from the hillslope to the stream channel. Use of a combination of remote and field evidence is likely the most successful strategy for identifying channel heads. This report presents a case study that demonstrates how a weight-of-evidence approach can combine field and remote evidence to locate the different parts of the transition and ultimately to identify the channel-head location.

3 Dec 2021

Data Collection Tools for River Geomorphology Studies: LiDAR and Traditional Methods

Abstract: The purpose of this review is to highlight LiDAR data usage for geomorphic studies and compare to other remote sensing technologies. This review further identifies survey efficiencies and issues that can be problematic in using LiDAR digital elevation models (DEMs) in completing surveys and geomorphic analysis. US Army Corps of Engineers (USACE) geospatial data collection guidance (EM 1110-1-1000) (USACE 2015) aligns with the American Society for Photogrammetry and Remote Sensing Positional Accuracy Standards for Digital Geospatial Data (ASPRS 2014). Geomorphic assessment technologies are rapidly evolving, and LiDAR data collection methods are at the forefront. The FluvialGeomorph (FG) toolbox, developed to support USACE watershed planning, is a recent example of the use of LiDAR high-resolution terrain data to provide a new, efficient approach for rapid watershed assessments (Haring et al. 2020; Haring and Biedenharn 2021). However, there are advantages and disadvantages in using LiDAR data compared to other remote sensing technologies and traditional topographic field survey methods.

12 May 2021

The Demonstration and Validation of a Linked Watershed-Riverine Modeling System for DoD Installations: User Guidance Report Version 2.0

Abstract: A linked watershed model was evaluated on three watersheds within the U.S.: (1) House Creek Watershed, Fort Hood, TX; (2) Calleguas Creek Watershed, Ventura County, CA; and (3) Patuxent River Watershed, MD. The goal of this demonstration study was to show the utility of such a model in addressing water quality issues facing DoD installations across a variety of climate zones. In performing the demonstration study, evaluations of model output with regards to accuracy, predictability and meeting regulatory drivers were completed. Data availability, level of modeling expertise, and costs for model setup, validation, scenario analysis, and maintenance were evaluated in order to inform installation managers on the time and cost investment needed to use a linked watershed modeling system. Final conclusions were that the system evaluated in this study would be useful for answering a variety of questions posed by installation managers and could be useful in developing management scenarios to better control pollutant runoff from installations.

12 May 2021

Channel Assessment Tools for Rapid Watershed Assessment

Purpose: Existing Delta Headwaters Project (DHP) watershed stabilization studies are focused on restoration and stabilization of degraded stream systems. The original watershed studies formerly under the Demonstration Erosion Control (DEC) Project started in the mid 1980s. The watershed stabilization activities are continuing, and because of the vast number of degraded watersheds and limited amount of yearly funding, there is a need for developing a rapid watershed assessment approach to determine which watersheds to prioritize for further work. The goal of this project is to test the FluvialGeomorph (FG) toolkit to determine if the Rapid Geomorphic Assessment approach can identify channel stability trends in Campbell Creek and its main tributary. The FG toolkit (Haring et al. 2019; Haring et al. 2020) is a new rapid watershed assessment approach using high-resolution terrain data (Light Detection and Ranging [LiDAR]) to support U.S. Army Corps of Engineers (USACE) watershed planning. One of the principal goals of the USACE SMART (Specific Measureable Attainable Risk-Informed Timely) Planning is to leverage existing data and resources to complete studies. The FG approach uses existing LiDAR to rapidly assess either reach-specific analysis for smaller more focused studies or larger watersheds or ecosystems. The rapid assessment capability can reduce the time and cost of planning by using existing information to complete a preliminary watershed assessment and provide rapid results regarding where to focus more detailed study efforts.

14 Oct 2020

The Demonstration and Validation of a Linked Watershed-Riverine Modeling System for DoD Installations – Patuxent Watershed, Maryland

Abstract: This work evaluated a linked watershed and riverine modeling system for the Patuxent River Watershed, Maryland against observed field data and model output from a watershed model. The performance objectives were computed for streamflow, sediment, total phosphorus, orthophosphorus, total nitrogen, ammonium, and nitrate using daily and monthly average model predictions and measured data. Hydrological Simulation Program – Fortran (HSPF) was used to compute runoff, sediment, and nutrient loadings, whereas the Hydrologic Engineer Center – River Analysis Sys-tem (HEC-RAS) was used to evaluate in-stream flow, channel sedimentation, and the fate/transport of nutrients. Model results were successful for calibration, validation, and management scenario analysis. Contaminants were not simulated for this watershed due to a lack of observed data to compare against. The study identified two implementation issues. First, while the Patuxent River did not experience dry bed conditions, where a stream may be intermittent, one can incorporate a very narrow slot at the low point in the cross-section to numerically keep the channel wet during very low flows. Second, to set up the linked model, there needs to be more observed water quality data to better constrain the HSPF output being used as boundary conditions to the HEC-RAS model.

25 Jun 2020

PUBLICATION NOTICE: Rapid Watershed Assessment Tools Based on High-Resolution Terrain Data

Abstract: The goal of this project was to develop rapid watershed assessment methods to estimate channel stability and sediment transport potential using high resolution terrain data (Light Detection and Ranging-LiDAR) to support US Army Corps of Engineers (USACE) watershed planning. This project developed a suite of tools based on advanced remote sensing technologies (LiDAR) that use off-the-shelf, high-resolution terrain data to rapidly assess watershed condition at the channel, floodplain, valley, and watershed scales. The widespread availability of high-resolution terrain data provides an opportunity to assess watershed conditions in great detail over large spatial extents. For this project, a channel assessment method was developed using a new LiDAR Hydraulic Geometry Relationships (HGR)-based approach for developing regional curves.

22 Apr 2020

PUBLICATION NOTICE: Nested Physics-Based Watershed Modeling at Seven Mile Creek: Minnesota River Integrated Watershed Study

ABSTRACT: The Minnesota River Basin (MRB) Integrated Study Team (IST) was tasked with assessing the condition of the MRB and recommending management options to reduce suspended sediments and improve the water quality in the basin. The Gridded Surface Subsurface Hydrologic Analysis (GSSHA) was chosen by the IST as the fine scale model for the Seven Mile Creek Watershed to help quantify the physical effects from best management practices within the MRB. The predominately agricultural Seven Mile Creek Watershed produces high total suspended solids and nutrients loads, contributing roughly 10% of the total load to the Minnesota River. GSSHA models were developed for a small experimental field research site called Red Top Farms, a Hydrologic Unit Code (HUC)-12 model for the entire Seven Mile Creek Watershed, a sub-basin of the Seven Mile Creek Watershed. After calibration, the resulting models were able to simulate measured tile drain flows, stream flow, suspended sediments, and to a lesser extent, nutrients. A selected suite of alternative land-use scenarios was simulated with the models to determine the watershed response to land-use changes at the small and medium scale and to test whether the type, size, and spatial distribution of land uses will influence the effectiveness of land management options.