For example, during field reconnaissance in 2003, deposition of sediment and large woody material in the tributary mouth bar upstream of Anderson Creek was observed; in 2004, a bioengineering project constructed

included vegetation planting, reducing bank angle, removing the bar, and utilizing the sediment to construct rock-willow baffles along modified stream banks. Extraction of gravel from bars has see more occurred periodically in Anderson Creek immediately downstream of the confluence with Robinson Creek. Detailed surveys reach extend 1.3 km from the confluence of Robinson Creek with Anderson Creek to the Fairgrounds Bridge, adjacent to downtown Boonville (Fig. 1). Residences and commercial structures are present on both sides of the channel, including two other bridges (Fig. 4). Eroding channel banks are widespread, riparian trees present on the terrace are remnants of the former riparian buy BMN 673 forest, and where present, tree roots are often exposed except where restoration planting within the channel has occurred. During field surveys in Robinson Creek during 2005 and 2008 we constructed a planimetric map (Fig. 4) by overlaying field data on a 2004 color photograph (Digital Globe, Inc; 1:6000). The top edge of the terrace bank

was defined from the photograph and approximated where obscured by vegetation. Longitudinal surveys, collected with an electronic distance meter (EDM) provided three profile data sets: thalweg profiles, bar surface profiles, and terrace edge profiles. We measured active channel width at the base of bank at irregular increments selected to document planimetric variation using a laser range finder and compass. Grain size measurements at eight locations followed the Wolman (1954) method. Bar and terrace heights were defined as the difference between the reach average thalweg elevations and the reach averaged tuclazepam bar surface and terrace elevations, respectively.

To illustrate changes in transport capacity at the scale of the study reach due to changes in gradient in the lower study reach, we first compared bed shear stress,τo, at time one (t1) when Robinson Creek was at the elevation of the terrace, and at time two (t2), or the present: equation(1) t1 τo1=γRS1t1 τo1=γRS1 equation(2) t2 τo2=γRS2t2 τo2=γRS2where the specific weight of water (9807 N/m3) γ = ρwg, where ρw is the density of water and g is the acceleration of gravity; R is the hydraulic radius; and S1 is the slope at t1 and S2 is the slope at t2. We then compared bed shear stress, τo, to the critical shear stress needed to initiate particle motion, τc, to derive excess shear stress using the Shields equation: equation(3) τc=τ∗(ρs−ρw)g D50τc=τ∗(ρs−ρw)g D50where Shields parameter for mobility, τ* = 0.035 ( Parker and Klingeman, 1982), ρs and ρw are the density of sediment and water, respectively, and D50 is the average median grain size.