Att 03_GI Rim Trail Culvert Plan.pdf

This document is a detailed engineering plan set for the Grand Island Rim Trail Improvement Project Culvert Replacement, prepared by the USDA Forest Service for the Hiawatha National Forest in Alger County, Michigan. The plan covers three specific culvert replacement sites (Sites #47, #48, and #50), each with comprehensive site plans, cross-section views, and profile layouts.

Key technical details include replacing existing culverts with new galvanized elliptical or round pipes, installing silt fences for erosion control, placing road gravel for surfacing, adding nonwoven geotextile beneath riprap, and ensuring proper grading and substrate installation. Each site has specific elevation measurements, pipe dimensions, and installation requirements. The culvert replacements range from 15" to 38" in diameter, with precise inlet and outlet invert elevations documented. The project involves removing existing clay or galvanized pipes and installing new culverts with natural stream substrate, maintaining a consistent trail width and managing surrounding terrain to ensure proper drainage and trail integrity.