Rivers: Streamflow Quantity and Quality

SESSION M: Rivers: Streamflow Quantity and Quality

Session Co-chairs: Robert Dudley and Tom Huntington, U.S. Geological Survey

Session Description: Rivers impact society in many ways including providing water for domestic, agricultural, industrial, recreational and aesthetic uses. Rivers are managed for a broad range of issues including hydropower and fish passage, flood-related hazards, TMDLs, and competitive water needs during periods of low flow. River systems also provide aquatic habitat for a variety of organisms and serve as a land-to-sea transportation network of many dissolved and sediment-related constituents including carbon, nitrogen, phosphorus, and contaminants. This session addresses status, trends, and societal impacts of streamflow quantity and quality in the northeastern U.S.

Presentations Available

Session Overview

1:30-1:55 pm
Maine StreamStats; a Tool for Calculating Basin Characteristics and Streamflow Statistics in Maine
Pamela J. Lombard, U.S. Geological Survey

This presentation will give a demonstration of Maine StreamStats, a U.S. Geological Survey web-based application that has recently been implemented for Maine in cooperation with the Maine Department of Transportation. Maine StreamStats computes consistent, unbiased, and defensible estimates of basin characteristics and streamflow statistics based on published regression equations and (or) long-term streamflow gaging data, at any user-selected rural stream location in Maine. Streamstats also allows users to trace flowpaths and identify stream reaches that are upstream and downstream from user-selected sites. Streamflow statistics computed in streamstats are useful for water-resources planning and management, and engineering design applications such as the design of bridges and culverts. Statewide streamflow statistics that are currently available for computation within streamstats include peakflows, mean and median monthly and annual flows, the 7-day 10-year lowflow, and bankfull discharge in some regions of the state. As additional Lidar data, streamflow data and regression equations become available for Maine, they can be integrated into the application.

2:00-2:25 pm
Climate change and flooding in New England
Glenn Hodgkins and Robert Dudley, USGS New England Water Science Center

Annual-maximum streamflows throughout New England generally have increased during the last century. Projected changes in precipitation and air temperature will result in additional changes in the future. Statistical analyses and watershed modeling of historic floods can be used to identify important drivers of floods, such precipitation and snowpack. This presentation will review historical trends in New England flood flows and in important drivers of floods. Causal mechanisms of some large historical floods will be discussed. We will summarize and discuss studies that have modeled future high flows and floods. Initial results indicate a complex relationship between changes in precipitation and air temperature and changes in floods because of the large influence of snowmelt runoff on flood flows in northern New England.

3:00-3:25 pm
The Social Dynamics of River Restoration
Eileen Sylvan Johnson, Kathleen Bell, Jessica Leahy; Bowdoin College, University of Maine

Our research examines the interaction between river water quality and regulatory levels, and responses within river communities to capitalize on river restoration achievements. Our investigation examines the spatial and temporal dimensions of classification of Maine rivers over a 40 year history as established by Maine Water Classification Acts of 1965, 1979, and 1987. Using the Androscoggin and Kennebec Rivers as a case study to explore social response, we examine the establishment of riverside amenities such as parks and trails to increase public access and enjoyment of river systems along these corridors during this same time frame as well as changes in landscape characteristics along these river corridors. Our research incorporates results from a survey of policy stakeholders on perceptions of water classification levels and public response.  By examining both restoration state and the emergence of parks and trails and green spaces along river corridors over the 40 year time frame since passage of the Clean Water Act, this research addresses the question as to whether amenities are established in response to water quality improvements or serve to build public support towards advocating for restoration measures. Despite historical differences in water classification levels, at present these two systems are comparable in the level amenity infrastructure and the predominance of green areas (forested, and vegetated areas) along the river corridor. However, we found important differences between the systems in terms of the pace of amenity development and landscape composition.

3:30-3:55 pm
Using Streambed Temperature Time Series and Pumping Tests to Characterize Groundwater and Stream Water Interaction in Northern Maine
Jarrod Cicha, Andrew Reeve, David Lemery; School of Earth & Climate Sciences, University of Maine

Groundwaters and surface waters are environmentally and economically significant resources that are intimately interconnected. Groundwater inflow influences stream ecosystems, including fish habitat, and this inflow may be impacted by local groundwater extraction. Balancing ecosystem needs for groundwater with human demands on aquifers requires a clear quantitative understanding of groundwater interaction with surface water. As a result, groundwater influx to B-stream (Houlton, Maine) is being quantified. Time series of vertical temperature data from the streambed were collected at 10-minute intervals for 2-week periods, seven times through the summer of 2014. Two arrays of 24 data loggers were installed near the edge of B-Stream in a rectangular configuration to collect streambed temperature at depths of 0cm, 8cm, 16cm, and 24cm. Temperature oscillations decrease from 3-4oC at the streambed to 0.5-1.0oC at depths of 24cm. Vertical groundwater velocities were calculated using measured temperature data to calibrate a one-dimensional finite-difference heat transport model. Best fits were determined by minimizing the sum of squared temperature residuals while systematically adjusting vertical groundwater velocity and porosity used in each simulation. Vertical groundwater velocities were upward and ranged from 1e5m/s to 3e6m/s with normalized sum of squares averaging 0.220oC and ranging from 0.163oC to 0.296oC. Hydraulic tests were conducted by pumping two bedrock wells located 10m and 35m from the edge of B-stream at rates of 2.8 to 5.7 liters/min. In the next phase of this project, temperature time series data will be evaluated in greater detail to determine the impact of hydraulic tests on vertical groundwater flow rates.