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  • 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.

  • Implementation of Flexible Vegetation into CSHORE for Modeling Wave Attenuation

    Abstract: This technical report presents the new numerical modeling capabilities for simulating wave attenuation and mean water level changes through flexible vegetation such as smooth cordgrass in coastal and marine wetlands. These capabilities were implemented into the Cross-SHORE (CSHORE) numerical model. The biomechanical properties of vegetation such as dimensions, flexibility, and bending strength are parameterized in terms of the scaling law. Correspondingly, a new formulation of the vegetation drag coefficient, CD, is developed using field data from a salt marsh in Terrebonne Bay, LA, by considering spatially varying effective stem and blade heights of species. This report also presents a general procedure for using the model to simulate hydrodynamic variables (i.e., waves, currents, mean water levels) at vegetated coasts, which are used to quantify the effects of wave attenuation and reduction of surge and runup due to vegetation. Preliminary model validation was conducted by simulating a set of laboratory experiments on synthetic vegetation, which mimicked the flexibility of Spartina alterniflora. The validation results indicate that the newly developed vegetation capabilities enable CSHORE to predict changes of wave heights and water levels through marshes by considering species-specific biomechanical features. The model is also applicable to assess vegetation effectiveness against waves and surges.

  • Celebrating World Wetlands Day

    World Wetlands Day was celebrated this week with the theme ‘Call to Act’ for Wetlands. It's an appeal to invest financial, human, and political capital to save the world’s wetlands from disappearing and to restore those we have degraded. It highlights the need to raise national and global awareness about wetlands to reverse their rapid loss and encourage actions to conserve and restore them. To protect against further loss, the nation has in recent years adopted a policy of "no net loss" of wetlands. USACE, working in partnership with many other organizations, is helping to implement this policy by protecting, preserving, and restoring.

  • Antecedent Precipitation Tool (APT) Version 1.0: Technical and User Guide

    Abstract: This document provides an overview of the technical components of the Antecedent Precipitation Tool (APT) and a user guide for using the APT. The APT is an automation tool that the US Army Corps of Engineers (USACE) developed to facilitate the comparison of antecedent or recent precipitation conditions for a given location to the range of normal precipitation conditions that occurred during the preceding 30 yr¹. In addition to providing a standardized methodology to evaluate normal precipitation conditions (“precipitation normalcy”), the APT can assess the presence of drought conditions and the approximate dates of the wet and dry seasons for a given location.

  • Engineering With Nature®: Supporting Mission Resilience and Infrastructure Value at Department of Defense Installations

    Abstract: This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at seven military installations to achieve increased resilience through natural infrastructure.

  • Expert Elicitation Workshop for Planning Wetland and Reef Natural and Nature-Based Features (NNBF) Futures

    Abstract: This special report discusses the outcomes of a September 2019 workshop intended to identify barriers to the consideration and implementation of natural and nature-based features (NNBF) in US Army Corps of Engineers (USACE) civil works projects. A total of 23 participants representing seven USACE districts, the US Army Engineer Research and Development Center (ERDC), and the University of California–Santa Cruz met at USACE’s South Atlantic Division Headquarters in Atlanta, Georgia, to discuss how to facilitate the implementation of NNBF into USACE project planning for wetlands and reefs using six categories: (1) site characterization, (2) engineering and design analysis, (3) life-cycle analysis, (4) economic analysis, (5) construction analysis, (6) and operation and maintenance (and monitoring). The workshop identified seven future directions in wetland and reef NNBF research and development: • Synthesize existing literature and analysis of existing projects to better define failure modes. • Determine trigger points that lead to loss of feature function. • Identify performance factors with respect to coastal storm risk management (CSRM) performance as well as ecological performance. • Focus additional research into cobenefits of NNBF. • Quantify the economic life-cycle costs of a project. • Improve technology transfer with regards to NNBF research and topics.

  • From the Wicomico River to Deal Island

    The U.S. Army Corps of Engineers, Baltimore District, and several local, state and federal agencies have been partnering up to find a new placement site on the eastern shore of Maryland for material dredged from the Wicomico River. After extensive research and evaluation, USACE and partners agreed on the Deal Island Wildlife Management Area in Somerset County to hold the material and also provide beneficial long-term environmental benefits.

  • Remotely Sensed Habitat Assessment of Bottomland Hardwood and Swamp Habitat: West Shore Lake Pontchartrain Hurricane Storm Damage Risk Reduction System Potential Impact Area

    Purpose: This study used remote sensing techniques to identify and assess the current condition of bottomland hardwood (BLH) and swamp habitats within the West Shore Lake Pontchartrain (WSLP) hurricane storm-damage risk reduction system (HSDRRS) project area. This effort provides baseline knowledge of the location and quality of these habitats prior to the construction of the WSLP HSDRRS project. The resultant products will assist the USACE—New Orleans District (MVN) by informing ecosystem decision-making related to environmental assessments.

  • DOJ: Agricultural Developer Agrees to Pay Clean Water Act Fines, Mitigate Impacts to Sensitive Streams and Wetlands

    A California agricultural developer has agreed to pay a civil penalty, preserve streams and wetlands, effect mitigation, and be subject to a prohibitory injunction to resolve alleged violations of the Clean Water Act (CWA) on property near the Sacramento River located in Tehama County, California, the Justice Department announced today.

  • Chief of Engineers signs Grand River Basin Study – on to Congress

    Lt. Gen. Scott A. Spellmon, USACE Commanding General and 55th U.S. Army Chief of Engineers, signed the Chief’s Report for the Grand River Basin Study on November 19, 2020. The signing of the report progresses the project to Congress for authorization. “I am grateful for the hard work of the entire team and for the outstanding partnership with the State of Missouri, other federal agencies, and the local communities in this area. The partnership is what made this important study successful. This is a great example of improving habitats and the environment while also increasing flood protection in an area. Ultimately, it will greatly benefit the people, the economy, the environment, and the many areas of the Grand River Basin,” said Col. Bill Hannan, commander, Kansas City District.