Drainage Design Solutions of Different Topographies

Question: 

What is the best approach when designing fields for drainage?

Answer:

Based on our experience designing 100,000s of acres, we have come up with these rules of thumb:
  • Flatter Fields Suit Landforming Alone: On fields with relatively low slopes (e.g. less than 0.5%) then there are often many small shallow depressions. Landforming is generally the best solution as minor cutting and filling can solve the problem most cost effectively.
  • Fields Not Steep and Not Flat Suit Landforming & Drains Combined: Between the flat and steep categories (e.g. 0.5% - 1.0% slope), the solution is generally a combination of ditching and landforming.
  • Steeper Fields Suit Drains Alone: On fields with higher slopes (e.g. greater than 1%), the flows paths are often easily defined and larger deeper depressions may exist. Cutting drains between the depressions is probably the most cost effective solution and putting the cut soil in the depressions can raise the required elevation of the drain network and reduce the total cut volume.
Below are examples of these three different design styles in action.

• Flatter Fields Suit Landforming Alone


Existing Topography


Drainage Analysis


Proposed Topography


Proposed Cut/Fill Map



• Fields Not Steep and Not Flat Suit Landforming & Drains Combined

Existing Topography


Drainage Analysis


Proposed Topography


Ditch Long Section


Ditch Cross Section


Note: Vertical is exaggerated. This example shows a drain channel about 0.8ft deep with 15ft wide flat base that batters up to the surface at 1:20.

Proposed Cut/Fill Map



• Steeper Fields Suit Drains Alone

Existing Topography


Drainage Analysis


Proposed Topography


Note: This complex ditch network is not actually 60ft wide. It was just designed as so to create a flat base to have a reference for the control file.  The scraper will only follow the center line.

Proposed Cut/Fill Map


Main Ditch Long Section




Tips and Tricks

  1. Erosion Control Banks & Waterway
  2. Drainage Design Solutions of Different Topographies
  3. Runoff vs Slope
  4. Trimble Field Level II Do Not Show the .gps File
  5. Minimum Recommended Smoothing Distance For Export To Trimble Field Level 2
  6. GPS Base Station Setup For Best Vertical Accuracy
  7. How to Survey with Trimble FMX
  8. How Easy is OptiSurface to Use for the Average Farmer?
  9. Balancing Earthworks in the Field
  10. Landform Design Slopes and Smoothing
  11. Export Proposed Topography to AutoCAD
  12. Surface Irrigation Designs with Variable Slope
  13. OptiSurface Designer Import and Export Format
  14. Importing Multiple Survey Files to OSD
  15. Can Drone Or LIDAR Surveys be used with OptiSurface?
  16. Calculation Grid Spacing and Export Grid Spacing
  17. How to Survey a Field for Landforming Design
  18. Loading .gps File in FmX
  19. Designing a Field in Sections
  20. Using an Old OSD File versus a New Survey
  21. No Master Benchmark on Imported Survey File
  22. Displaying Secondary Benchmarks
  23. Import Error for xyz File Due to Encoding Format
  24. OptiSurface4D: Bounded By Ridges
  25. Can OptiSurface handle curved rows in Drainage Analysis & Runoff Analysis?
  26. Reverse Grades to Main Slope
  27. Measuring Culvert Invert Level
  28. Surveying a 1000-Ha Field
  29. GPS Coordinate System Check
  30. Does A Normal UTM Zone Coordinate Need To Be Trimmed To x Digits?
  31. Can You Import Data Directly From GPS System?
  32. Converting Latitude/Longitude to Easting/Northing
  33. Surveying With Any GPS Equipment and Exporting to a gps file for the Trimble FMX
  34. DGPS Post Treating System with 5cm Precision For Landforming
  35. Exporting to Trimble FMX Field Level
  36. Can I Survey with a GPS System on an ATV?
  37. Standard NMEA GPGGA txt File to Import into OptiSurface Designer
  38. 900 Acres: Cut that large survey down.
  39. Export Options for Data Layers
  40. Import Two or More Survey Files to Reach Minimum Area
  41. Different Row Slope Directions In One Field
  42. Does OptiSurface allow for multiple grade breaks per design, taildrains roads, pads etc?
  43. Can I View DTM/Topography In Plan View Or 3D Type View When Doing A Design?
  44. Adjust the Bands in the Legend
  45. Design for a 1000-Ha Field
  46. Would It Be Possible That The Numbers In The Boundary Zone Appear In The New Subzone Created?
  47. Grade Of Best Fit And Splitting The Field Into Boundaries
  48. Acceptable Minimum Slopes
  49. Incorrect Area in OptiSurface
  50. Valley Subzone Not Behaving as Expected
  51. Difference Between Breaklines And Subzones
  52. Alignment of Furrow/Bed Direction with OptiSurface Design Mainslope Direction
  53. Subzones Settings Over Ride Boundary Zone Settings
  54. Printing the Maps
  55. Print Size

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