Diverse Experience in Stream Stabilization and Restoration
WRMA's stream restoration specialists have experience in the stabilization and restoration of a variety of stream classifications in a multitude of geographic locations. For over 10 years WRMA has served municipal agencies, state district departments of transportation (DOTs) and water utilities throughout the Southeast and Mid-Atlantic states in performing hydraulic assessments and stream restoration projects. WRMA's stream restoration team includes professional engineers with decades of experience in hydraulic modeling and hold nationally recognized certifications in flood plain management (CFM) from the Association of State Flood Plain Managers. Due to WRMA's decades of experience in hydraulic engineering and stream restoration, the firm has vast knowledge of both federal (FEMA) and state (DOT) regulations and guidelines as they pertain to floodplain management and stream restoration design.
Stream Assessment, Restoration and Resource Management Services
As a water resources engineering firm, WRMA believes in proactively managing water resources including streams within a watershed. Many counties now are realizing the value of initializing stream management programs in an effort to reduce the large expense associated with performing snap emergency stream restoration projects. WRMA works with counties, cities, water management districts and water utilities to identify their stream restoration goals and design intermittent stream monitoring and maintenance programs combined with restoration projects to proactively manage streams throughout a watershed and help organizations effectively manage O&M resources and protect capital assets such as sewer infrastructure from being threatened by unstable stream systems. WRMA can also assist cities and counties with recording and reporting annually the linear footage of stream restored to get credit from state regulators for the purposes of maintaining MS4 permit conditions.
What is Stream Restoration?
The main objective of a stream restoration project is to re-establish the general structure, hydraulic function, natural aesthetic and self-sustaining behavior of a given stream system that existed prior to becoming destabilized due to natural geomorphologic processes or in some cases, man-made events. The process of stream restoration is a holistic one in that it requires an understanding of the physical and biological elements of the stream system and its watershed. Stream restoration projects are often initialized in response to an event or as part of a general maintenance cycle in a given watershed. Over time, all streams undergo a variety of changes including changes to the stream's alignment, bank vegetation, velocity profile, cross sectional area and width. For example, natural streams tend to meander relative to a fixed point, due to a variety of changes in the surrounding environment upstream and downstream along a stream's alignment. Whenever changes to the channel, floodplain, vegetation, flow or sediment supply significantly affect the dynamic equilibrium state of a stream, the stream may become unstable and start adjusting toward a new equilibrium state.
Stream Restoration Design Services
WRMA's stream restoration specialists are experienced in performing hydraulic analyses of streams as part of stream stabilization or watershed assessments and can diagnose current or future potential issues which could affect the equilibrium state of a stream system. Following WRMA's stream stabilization assessment, WRMA's hydraulic engineering team can design countermeasures to help correct various hydraulic defects, from stream realignment and bank stabilization to in-stream structures and asset protection including:
- Rock Vanes
- Riffle Grades
- Step Pools
- Boulder Replacement
- Imbricated Riprap
- Rock/Boulder Toes
- Pipe Asset Protection
- Manhole Armoring
Post-Restoration Monitoring Services
WRMA's stream restoration design countermeasures can help to re-establish hydraulic function and self-sustaining behavior. However, WRMA also provides field monitoring during construction and post-restoration to ensure that countermeasures were correctly installed and are effectively protecting the restored portion of the stream from destabilization. One contributing factor to the destabilization of stream systems in urban areas is the continual expansion of cities and populations of people into the surrounding less developed areas of major metropolitan centers, a process commonly known as "urbanization".
Effects of Urbanization on Stream Stabilization
Despite the efforts of more stringent stormwater regulations, streams in urban areas are still prone to becoming destabilized due to the subsequent increases in flash flood events resulting from encroaching urbanization into the natural floodplain of a stream system. A flash flood event typically occurs when a storm event of very high intensity and short duration produces a large quantity of stormwater runoff which quickly exceeds stormwater control thresholds, discharging runoff at high rates into receiving streams. At high velocity, stream flows can carry large debris such as fallen trees and can strip off bank vegetation resulting in large amounts of sediment to be transported downstream damaging wildlife habitat, eroding residential property and creating hydraulic problems for transportation infrastructure like roads, culverts and bridges.
Watershed Planning and Stream Stability Program Design
To promote long term stability, WRMA's hydraulic engineers, biologists, planners and stream restoration specialists can analyze projected land use, zoning maps and master plans to help identify locations where stream stability may be at risk due to future planned developments. Subsequently, armed with this information, WRMA can design monitoring and restoration programs to help mitigate the effects of future urbanization on a stream system. Long term watershed planning can become more effective and beneficial with the realization that stream systems are assets in themselves and provide important environmental and economic benefits to communities.