Channel Geometry Characteristics of Streams in Maryland

WRD PROJECT #: MD125
PROJECT CHIEF: Doheny, Edward J.
BEGIN DATE: 15-March-1998
END DATE: 30-September-2001

Customers currently supporting the project:

U.S. Fish and Wildlife Service
U.S. Geological Survey

Problem

The U.S. Fish and Wildlife Service (FWS), Chesapeake Bay Field Office has requested the assistance of the U.S. Geological Survey (USGS), Maryland-Delaware-D.C. District in an ongoing study of channel geometry characteristics of streams in Maryland. The results of the study will be used in the design and evaluation of stream crossings, stream-restoration projects, and watershed management programs throughout Maryland and in adjacent States. The work involves channel-geometry surveys for stream reaches in the vicinity of USGS streamflow-gaging stations. Stage-discharge and flood-frequency relations for the gaged streams are a critical component of the study. Because several active gaging stations in the Maryland Piedmont are on streams that are significantly affected by regulations and diversions, watershed urbanization, and channel construction, the number of gaging stations on natural streams needed for the study is not adequate. The expertise of the USGS was necessary to re-establish stage-discharge ratings at several inactive streamflow-gaging stations for use in the study in Fiscal Year 1998. In Fiscal Year 1999, the USGS began work to re-establish stage-discharge ratings at 10 discontinued USGS streamflow-gaging stations and crest-stage stations in the Valley and Ridge and Appalachian Plateau physiographic regions as part of phase II of the project. Additional work is anticipated in Fiscal Year 2000.

Objectives

The objective of the proposed work is to re-establish stage-discharge ratings at discontinued streamflow gaging stations in the Maryland Piedmont for use in an ongoing study of channel-geometry characteristics of streams in Maryland. The re-established ratings will aid in providing reliability to ongoing development of regional curves of channel-geometry characteristics for use in the design and evaluation of stream crossings, stream-restoration projects, and watershed management programs.

Approach

FWS has selected inactive gaging stations in the Maryland Piedmont as potential locations for re-establishment of stage-discharge ratings and updating of the rating table. These stations will have ratings re-established by conducting a series of 4 or 5 discharge measurements at each station. Measurements will be made such that a range of stages and discharges are used to develop the rating shape. The measurements for each station will be plotted and compared to the last active rating. A new rating will be drawn for the station based on the new measurements. A new rating table will be generated for each station. The new ratings will be presented to FWS with a cover letter explaining the results for each station.