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5 PROPOSED CONDITIONS MODELS <br />After establishing the revised existing conditions models to use as a baseline for comparison in Section <br />3, we developed the proposed conditions modeling in cooperation with RCWD to ensure compatibility <br />with the District modeling procedures. The proposed conditions reflect future land uses in the study area, <br />assumed site grading to drain the study area to the central storm drainage system, assumed private <br />disconnection of agricultural drain tile within the study area, and conceptual regional stormwater storage <br />BMPs connected by a new open conveyance system and revised outlet to Peltier Lake (Figure 13, <br />Appendix A and Appendix C). <br />5.1 Hydrology Updates <br />Curve numbers were estimated using the MLCSS, City of Lino Lakes, and City of Hugo 2030 projected <br />land uses, NRCS soil data, recent wetland delineations, and the National Wetland Inventory. The <br />following assumptions were made: <br />1. Hugo and Lino Lakes will be fully built out per their 2030 approved land use plans <br />2. Future development will be graded to drain to a regional BMP; this may include the use of drain <br />tile or imported fill to improve drainage in clay soils. A hydrologic soil group type B was assumed <br />for new development. <br />3. Existing wetlands within the RCWD Wetland Management Corridor (WMC) will be preserved or <br />restored per RCWD Rules within the WMC in Lino Lakes. Many of the existing wetlands have <br />been drained and are currently farmed. By protecting and improving the quality of the existing <br />wetlands, the proposed curve number is reduced in several subcatchments. <br />Tables 5-1 and 5-2 provide a summary of the land uses and curve numbers used in the modeling: <br />Table 5-1. Proposed Land Uses, Impervious Percentages, and Curve Numbers <br />LAND USE DESCRIPTION <br />MAX. IMPERVIOUS <br />PERCENTAGE 1 <br />A 2 <br />B 2 <br />C 2 <br />D 2 <br />TP s <br />[MG/L] <br />Large lot residential <br />10% <br />59 <br />74 <br />82 <br />86 <br />0.46 <br />Low density residential <br />40% <br />47 <br />65 <br />76 <br />82 <br />0.50 <br />Medium density residential <br />50% <br />54 <br />70 <br />79 <br />84 <br />0.30 <br />High density residential <br />65% <br />70 <br />81 <br />87 <br />90 <br />0.40 <br />Commercial <br />75% <br />86 <br />91 <br />93 <br />94 <br />0.22 <br />Industrial <br />75% <br />81 <br />88 <br />91 <br />93 <br />0.25 <br />Public semi-public <br />65% <br />39 <br />61 <br />74 <br />80 <br />0.18 <br />Vehicular right-of-way <br />75% <br />83 <br />89 <br />92 <br />93 <br />0.25 <br />Mixed use <br />75% <br />77 <br />85 <br />90 <br />92 <br />0.22 <br />Wetland management corridor <br />0% <br />30 <br />58 <br />71 <br />78 <br />0.03 <br />1 Lino Lakes 2030 Comprehensive Plan <br />2 NRCS National Engineering Handbook <br />3 MPCA Minnesota Stormwater Manual <br />Comprehensive Stormwater Management Plan <br />Northeast Lino Lakes Drainage Improvement Project <br />WSB Project No. 2929-79 <br />Page 15 <br />