INFORMATIONAL MEETING Improvement of Judicial Ditch No. 24 Jackson - PowerPoint PPT Presentation

INFORMATIONAL MEETING Improvement of Judicial Ditch No. 24 Jackson County, MN June 6, 2019

Location and Scope of Improvement

Location and Scope of Improvement - JD 24 Watershed - Jackson Co. Round Lake Twp. – Portions of 17 Sections - Nobles Co Indian Lake Twp. – Portions of 4 Sections - Total JD 24 Watershed = 8,130 Acres - Petition Location - Branch B, Branch Q, Branch S, Branch T, Branch U

Existing Ditch System - Petitioned for Establishment 1913 - Original Construction = 1917

Capacity of Existing Drainage System - Analysis used Standard Engineering Methods - Tiles – Manning Equation - Recommended Standards - Natural Resources Conservation Service (NRCS) - 1/2” of runoff per day

Capacity of Existing Drainage System Calculated Existing Drainage NRCS Flow Existing Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.013 Branch B Br. B2 Confluence 58 1.21 8” 0.10 0.38 0.16 Br. B1 Confluence 142 2.97 8” 0.10 0.38 0.06 Outlet to Open Ditch 176 3.69 8” 0.20 0.54 0.07 Branch B1 Branch B Confluence 34 0.72 6” 0.10 0.18 0.12 Branch B2 Branch B Confluence 50 1.04 8” 0.10 0.38 0.18

Capacity of Existing Drainage System Calculated Existing Drainage NRCS Flow Existing Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.013 Branch Q No. of CSAH 4 184 3.87 8” 0.20 0.54 0.07 14” 0.05 1.20 Br. Q5 Confluence 410 8.61 0.25 20” 0.05 3.12 14” 0.05 1.20 W ½ Sec. 20 560 11.77 0.18 20” 0.05 3.12 15” 0.05 1.45 Br. Q3 Confluence 662 13.91 0.16 20” 0.05 3.12 15” 0.05 1.45 Br. Q2 Confluence 704 14.78 0.15 20” 0.05 3.12 15” 0.10 2.05 Br. Q1 Confluence 718 15.09 0.21 20” 0.10 4.41 15” 0.20 2.90 Outlet to Open Ditch 795 16.71 0.27 20” 0.20 6.24 Br. Q1 Branch Q Confluence 15 0.31 6” 0.20 0.25 0.41 Br. Q2 Branch Q Confluence 41 0.87 8” 0.20 0.54 0.31 Br. Q3 Branch Q Confluence 102 2.14 10” 0.05 0.49 0.11 Br. Q4 Branch Q Confluence 123 2.58 10” 0.10 0.69 0.13 Br. Q5 8” 0.10 0.38 Branch Q Confluence 103 2.17 0.25 10” 0.10 0.69

Capacity of Existing Drainage System Calculated Existing Drainage NRCS Flow Existing Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.013 Branch S No. off CSAH 4 62 1.29 8” 1.00 1.21 0.47 N ½ Sec. 19 293 6.16 10” 0.10 0.69 0.06 Outlet to Open Ditch 469 9.85 12” 0.30 1.96 0.10 Branch T Upper End 751 15.77 15” 0.05 1.45 0.05 No. of 720th St. 1006 21.13 18” 0.05 2.36 0.06 Br. T1 Confluence 1093 22.96 18” 0.20 4.71 0.10 Outlet to Open Ditch 1184 24.88 18” 0.20 4.71 0.09 Br. T1 Confluence With Branch T 91 1.92 8” 0.25 0.61 0.16 Br. T2 Confluence With Branch T 72 1.52 8” 0.10 0.38 0.13

Capacity of Existing Drainage System Calculated Existing Drainage NRCS Flow Existing Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.013 Branch U So. of CSAH 5 17 0.36 8” 0.40 0.77 1.08 Br. U5 Confluence 111 2.34 12” 0.10 1.13 0.24 SW ¼ Sec. 32 142 2.98 12” 0.10 1.13 0.19 Br. U4 Confluence 197 4.14 12” 0.10 1.13 0.14 W ¼ Corner Sec. 32 302 6.35 12” 0.10 1.13 0.09 Br. U3 Confluence 401 8.41 15” 0.10 2.05 0.12 So. Of 710th St. 443 9.30 15” 0.12 2.24 0.12 No. of 710th St. 456 9.59 15” 0.10 2.05 0.11 Br. U2 Confluence 471 9.90 15” 0.10 2.05 0.10 Br. U1 Confluence 518 10.89 15” 0.20 2.90 0.13 Outlet to Open Ditch 560 11.77 15” 0.20 2.90 0.12 Br. U3 Confluence with Branch U 98 2.07 8” 0.26 0.62 0.15 Br. U4 Confluence with Branch U 55 1.16 8” 0.20 0.54 0.23 Br. U5 W. of CSAH 5 56 1.18 8” 0.10 0.38 0.16 Confluence with Branch U 95 1.99 8” 0.10 0.38 0.10

Capacity of Existing Drainage System Approximate Branch % of NRCS Coefficient No. Standard (in/day) Branch B 1/16” 14% Branch Q 3/16” 41% Branch S 1/8” 20% Branch T 1/8” 18% Branch U 1/8” 24%

Proposed Improvements Proposed Drainage Features - Replace existing tile - 6-inch to 36-inch tile - Township road crossings – Open Trench - County Road Crossings – Trenchless - Lower than the existing tile - At least four feet of cover

Proposed Improvement Design Data - Proposed grades range from 0.10% to 2.9% - Type of Pipe - Dual Wall Polyethylene Drain Tile - Pipe deeper than 6’ will be non-perforated - Precast Reinforced Concrete Pipe - Design Criteria - Natural Resources Conservation Service (NRCS) - 1/2” of runoff per day

Proposed Improvement Calculated Proposed Drainage NRCS Flow Proposed Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.012 Branch B Br. B2 Confluence 58 1.21 10” 0.50 1.68 0.69 Br. B1 Confluence 142 2.97 12” 0.60 3.00 0.50 Outlet to Open Ditch 176 3.69 12” 1.20 4.24 0.57 Branch B1 Branch B Confluence 34 0.72 8” 0.40 0.83 0.58 Branch B2 Branch B Confluence 50 1.04 10” 0.50 1.68 0.81 Branch Q No. of CSAH 4 184 3.87 15” 0.35 4.15 0.54 Br. Q5 Confluence 410 8.61 30” 0.10 14.09 0.82 W ½ Sec. 20 560 11.77 30” 0.10 14.09 0.60 Br. Q3 Confluence 662 13.91 30” 0.10 14.09 0.51 Br. Q2 Confluence 704 14.78 30” 0.11 14.78 0.50 Br. Q1 Confluence 718 15.09 30” 0.45 29.89 0.99 Outlet to Open Ditch 795 16.71 30” 0.15 17.26 0.52 Br. Q1 Branch Q Confluence 15 0.31 6” 2.00 0.86 1.41 Br. Q2 Branch Q Confluence 41 0.87 8” 1.20 1.44 0.83 Br. Q3 Branch Q Confluence 102 2.14 15” 0.10 2.22 0.52 Br. Q4 Branch Q Confluence 123 2.58 18” 0.12 3.95 0.77 Br. Q5 Branch Q Confluence 103 2.17 15” 0.15 2.72 0.63

Proposed Improvement Calculated Proposed Drainage NRCS Flow Proposed Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.012 Branch S No. off CSAH 4 62 1.29 8” 1.00 1.31 0.51 N ½ Sec. 19 293 6.16 24” 0.10 7.77 0.63 Outlet to Open Ditch 469 9.85 24” 0.16 9.83 0.50 Branch T Upper End 751 15.77 30” 0.13 16.06 0.51 No. of 720th St. 1006 21.13 36” 0.13 26.12 0.62 Br. T1 Confluence 1093 22.96 36” 0.16 28.98 0.63 Outlet to Open Ditch 1184 24.88 36” 0.16 28.98 0.58 Br. T1 Confluence With Branch T 91 1.92 12” 0.25 1.94 0.50 Br. T2 Confluence With Branch T 72 1.52 10” 0.80 2.13 0.70

Proposed Improvement Calculated Proposed Drainage NRCS Flow Proposed Tile Calculated Tile Tile Location Area (CFS) Tile Size Capacity Coefficient Grade (Acres) 1/2”/Day (Inches) (CFS) (In. Per Day) (%) n=0.012 Branch U So. of CSAH 5 17 0.36 6” 1.00 0.61 0.86 Br. U5 Confluence 112 2.35 15” 0.16 2.81 0.60 SW ¼ Sec. 32 132 2.77 15” 0.16 2.81 0.51 Br. U4 Confluence 251 5.27 24” 0.10 7.77 0.74 W ¼ Corner Sec. 32 302 6.35 24” 0.10 7.77 0.61 Br. U3 Confluence 401 8.41 24” 0.12 8.51 0.51 So. Of 710th St. 443 9.30 24” 0.15 9.52 0.51 No. of 710th St. 456 9.59 24” 0.15 9.52 0.50 Br. U2 Confluence 471 9.90 24” 0.16 9.83 0.50 Br. U1 Confluence 518 10.89 24” 0.20 10.99 0.50 Outlet to Open Ditch 560 11.77 24” 0.23 11.79 0.50 Br. U3 Confluence with Branch U 98 2.07 12” 0.40 2.45 0.59 Br. U4 Confluence with Branch U 55 1.16 10” 0.45 1.60 0.69 Br. U5 W. of CSAH 5 56 1.18 15” 0.10 2.22 0.94 Confluence with Branch U 95 1.99 15” 0.10 2.22 0.56

Proposed Improvement • Strip and replace topsoil in the trench area • Riprap at the outlet • Construct new intakes

Proposed Improvement • Tile System Depth Tile Branch Minimum Depth Maximum Depth Branch B 5.4’ 12.8’ Branch Q 4.5’ 17.5’ Branch S 5.2’ 13.9’ Branch T 6.4’ 21.3’ Branch U 5.0’ 16.4’

Proposed Improvement • Water and Sediment Control Basin (WASCOB) • An embankment across the slope of a field or minor waterway • Temporarily detain water. • Traps sediment and slows down water • Proposed WASCOB at the outlet for Branch B • Close in the open waterway to the Open Ditch • Create 5.1 acre-feet of storage • Proposed WASCOB for Branch T • Construct a Berm through an opening in an old railroad embankment • 40 foot wide top with 1V:20H or flatter sides • Create 20 acre-feet of storage

Adequacy of the Outlet • JD 24 Open Ditch • The Improvement creates a net increase in flow of 6 cfs • Assume peak flows from the tile and the ditch occur at the same time • Estimate change in peak elevation and flow rates in the JD 24 Open Ditch