Difference Between Grading Plan and Drainage Plan

Grading Plan

Grading Plan is a detailed diagram that shows the proposed changes to the elevation or contours of the land. It outlines how the land's surface will be shaped or altered to meet certain design requirements.

• Focus: Concerned with elevation changes such as cutting, filling, or leveling the land.
• Key Features:
  • Contours: Represent changes in elevation.
  • Cut and Fill Areas: Indicate areas where material will be removed or added.
  • Slopes: Defines steepness for proper drainage and stability.
  • Finished Grade: The final elevation of the surface after grading is complete.
• Purpose: Ensures the land is shaped correctly for construction and provides a stable foundation.

Drainage Plan

Drainage Plan focuses on how water will flow across the site and how it will be managed to avoid flooding, erosion, and other water-related issues.

• Focus: Concerned with water flow management to prevent flooding and direct stormwater safely.
• Key Features:
  • Stormwater Drainage System: Includes storm drains, catch basins, and outfalls.
  • Retention and Detention Ponds: Areas to store or slow down stormwater.
  • Flow Patterns: Direction of water flow across the site.
  • Water Control Structures: Includes swales and berms.
• Purpose: Ensures proper stormwater management to prevent water accumulation and flooding.

Key Differences

• Focus:
  • Grading Plan: Focuses on elevation changes and shaping the land.
  • Drainage Plan: Focuses on managing and directing water flow to prevent flooding.
• Function:
  • Grading Plan: Determines how land will be reshaped for construction.
  • Drainage Plan: Designs the stormwater management system to handle water flow.
• Purpose:
  • Grading Plan: Ensures proper surface shape for construction and access.
  • Drainage Plan: Prevents flooding and directs water away from structures.