Sediment Transport Rates in the Lower Muskegon River and Tributaries

Abstract

Despite the presence of an economically important recreational fishery and recent relicensing of a series of major dams, few studies of sediment transport have been conducted on the Muskegon River. Stakeholder concerns about bank erosion and excessive deposition of fine sediments put pressure on decision-makers to take costly management actions of unknown effectiveness. One component essential to a comprehensive evaluation of sediment management activities is the establishment of sediment transport baselines for the system.

This study made use of basin-wide multiple linear regression (MLR) models to evaluate patterns of bedload and suspended sediment load at 19 sites on the Muskegon River and three tributaries from July 2003 to January 2006. Bedload transport was modeled using a MLR that included discharge and median diameter of the bed material at each transect (R2=0.82). A MLR model incorporating discharge and proportion agriculture in the watershed explained even more (R2=0.90) of the variation in suspended sediment transport across the basin.

Coupling of these models to daily discharge series allowed the estimation of annual sediment yields across the basin. Of the tributaries examined, Bigelow Creek was estimated to supply 842 Mg•yr-1 of bedload while Cedar Creek and Brooks Creek yielded much more (5989 Mg•yr-1 and 6911 Mg•yr-1, respectively). Suspended sediment loading into the lower Muskegon River from tributary sources was 229 Mg•yr-1 for Bigelow Creek, 1760 Mg•yr-1 for Cedar Creek and 4968 Mg•yr-1 for Brooks Creek. These amounts are relatively insignificant compared to the loads mobilized in sandy reaches on the Muskegon River below Croton Dam (e.g. 152,519 Mg•yr-1 bedload and 73,191 Mg•yr-1 suspended load at the B-31 Access site). These high loads generated an average annual sediment surplus of 55,000 Mg•yr-1 (or 35,000 m3•yr-1) between Holton Duck Lake Road and the US-31 causeway.

Although the Muskegon River has been impacted both by impoundment and dam removal, sediment loads appeared to be within the typical range for rivers of similar size in the Great Lakes and Upper Mississippi River Valley. Nevertheless, much more work needs to be done on the Muskegon River and other rivers in the region in order to better quantify sediment baselines and prepare for future sediment-related issues.

The understanding of sediment transport relationships gained from this study should provide a good starting point for resource managers and policymakers to begin addressing sediment issues within the basin.