Back to J Session Agenda

Maryland County Level Sub-Regional Curve Development

Reid Cook
RES (Resource Environmental Solutions)
Warrenton, VA

Christine Pankow
RES

Authors:  Reid Cook and Christine Pankow

Regional curve empirical relationships with drainage area have been an invaluable tool in the field of stream restoration since Leopold first described hydraulic geometry in the 1950s.  Typically, regional curves are developed for specific hydro-physiographic provinces and cover a large variation in drainage areas.  However, due to the lack of data in smaller watersheds, channel geometry data is often extrapolated beyond the range of regression values, which increases the risk of incorrect identification of channel dimensions.  Due to this limitation in existing published reports, RES staff collected data and developed a sub-regional curve for smaller watersheds in Prince George’s County, Maryland.  This sub-regional data did vary from other published non-tidal coastal plain regression curves and have proven a valuable tool in the development of projects. 

RES staff surveyed and compiled data on over seventy (70) stable riffle cross sections in systems with drainage areas ranging from 0.015 to 2.05 square miles.  These data were utilized to develop sub-regional curves (AreaBKF, WidthBKF, and DepthBKF) that were used to better inform design decisions on approximately 27,000 linear feet of stream restoration for the Prince George’s County Clean Water Partnership.   

In addition to multiple completed projects, RES is currently working on eight (8) other stream restoration projects in Prince George’s County and continue to add data to the previously developed regression models.  With increased data, the sub-regional curves can be further refined to improve proper channel sizing when used in conjunction with site-specific hydraulic geometry data.  In this presentation, the authors will discuss the development, use, limitations, variation in data, and comparisons with other published coastal plain curves.