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Stream Stabilization I & E Form ILLINOISNRCS-Version 3.2-modiried4/2008R.Book <br /> County ;Macon T. 17N R. 3E Sec. 14 <br /> Date 4/27/22 By Rob Meats <br /> Stream Name unnamed trib of Lake Decatur UTM Coord. <br /> Landowner Name Ron Helm <br /> Drainage Area 2.68 sq.mi. Cl�Cea. <br /> Regional Curve Predictions: <br /> Bankfull dimensions Width 22 ft. Cross Sectional Area 44 sq.ft. <br /> Depth 2.0 ft. <br /> Reference Stream Gage: <br /> Station No. - Gage 02 <br /> none ! Drainage Area - Regression <br /> 0 - REFERENCE STREAM DATA ONLY <br /> USGS Flood-Peak Discharge Predictions: <br /> Valley Slope: 14.0 ft/mi. (user-entered) Regression q 188 ds <br /> f 1mi(from worksheet) Rainfall 3.20 in (2 yr, 24 hr) Adjusted Q2 - <br /> 0.0027 Uft. Regional Factor 0.805 Typical Range for Bankfull Discharge <br /> 70 to 160 cis <br /> Local Stream Morphology.• <br /> Channel Description: ;(c) dean.winding.some pools and shoals j <br /> Manning's"n" 0.04 <br /> Stream Length 2778 ft. <br /> Basic Field Data: Valley Length 2427 ft. <br /> Bankfull Width 23 ft. Contour Interval 10 feet • <br /> Mean Bankfull Depth 1.8 ft. Estimated Sinuosity 1.14 <br /> Width/Depth Ratio 12.78 <br /> Channel slope: Bankfull Q from: <br /> Max.Bankfull Depth 2.7 ft. Surveyed: ft./ft. Cross-Section 137 cfs <br /> Width at twice max.depth 63 ft. Estimated: 0.00360 ftA. Basic field data 137 cis <br /> (5.4 ft.) Selected Q 135 cis <br /> Entrenchment Ratio 2.74 Radius of Curvature(Rc) 100 ft. <br /> Rc/Bankfull width: 4.35 <br /> Bankfull Velocity Check: tca/Illinois streams will have average bankfull velocity between 3 and 5 ft/sec. <br /> Bedload: D90 3 • in. velocity requirecl to move 3.6 Usec. <br /> Dso in. Velocity from Cross-Section data 3.13 Usec. <br /> GOAL:Develop confidence by matching Velocity from basic field data: 3.31 Usec. <br /> velocities from different sources. Velocity from selected Q: 3.3 ft✓sec. <br /> Channel Evolution Stale (Iv Stream Type(Rosgen) <br /> Notes <br /> Page 158 of 221 <br />