# Drain Design Tools
When designing drains, there are several aspects that you will find that are across all the different Drain Design tools.
The most important feature of the drain design tools that you will find will be the cross section found at the bottom of the screen. The cross section displays all the ups and downs along the drain surface.
The cross section is made up of three different lines. The Red line is the proposed design that you are currently working on. The Blue line is the existing surface that has been surveyed. The Yellow dotted line is the current design surface, when starting a new design this will be overlapped with the Blue line and when a design is applied it will overlap with the Red line UNLESS a second design is being made on top of that.
# Auto-Drains Design
You can use Auto-Drains to automatically generate drain paths for wet areas in your field. It will calculate optimal ditch lines to drain depressions.
There are two tab pages present in Auto-Drains:
1. ‘Create’ controls the parameters that must be met before drains are applied to the surface.
2. ‘Edit Drains’ allows for editing of the drain paths.
'Create"
'Edit'
# Create Drains
‘Line smoothing strength’ adjusts how many sharp turns and how smoothly the drain lines flow. The further to the right the slider is the more round the lines will be (with decreased sharp turns).
‘Surface smooth strength’ adjusts the surface by applying an averaging filter to the surface of the field to remove bumps and dips without creating a full field earthwork design.
'Min. drain length' will set the minimum length a drain must be to be displayed on the surface.
‘Min. depression area' will set the minimum surface area a depression must cover before T3RRA software will consider draining it.
'Min. depression volume' allows you to also set a minimum volume for a depression before a drain will be implemented.
‘Add Stop Line’ will create a black line on the screen with large red anchors at each end. Drain lines will not cross this line. To confirm the placement, press the ‘Lock Stop Lines’ button that will appear next to the ‘Add Stop Line’ button. Pressing the white anchor in the center of the lines will create another red anchor so that lines can be adjusted. Additional stop lines can be added by pressing the ‘Add Stop Line’ button again.
A depression will only be drained if it meets all of the minimum length, area, and volume criteria.
# Edit Drains
The ‘Existing Drains’ list will show all drains in the current project.
- Tapping on any of the drains in the list will select or unselect it. Multiple drains can be selected.
- Pressing the ‘Delete’ button while drains are selected will delete all of the selected drains.
- The ‘Delete All’ button will delete all drains in the list (even if they have not been selected).
- The ‘Move Lines’ button will change all the drain lines on the surface (shown in bottom image).
- Drain lines will have blue dots along them to indicate they can be moved to adjust the drain path.
- When moving drain lines always start at the origin point (which can also be moved) and move downhill.
- The drain lines will automatically adjust their paths according to your changes to ensure they flow off the edge of the surface.
- Press 'Save Changes' to keep changes or ‘Discard Changes’ to revert to the original paths.
NOTE: If you make an adjustment on a drain line and make a second adjustment closer to the origin point the first adjustment will revert to the line's original state. Auto-drains ALWAYS flow downhill from the point of the last change.
Once you are happy with the drains go back to the wizard page and use the ‘Drain Design’ function to set their profiles and cross sections.
# Pattern Drain Design
This design tool allows for simple design of many parallel drains at once.
The pattern drain window allows you to select specific drains to delete.
The 'Delete' and 'Clear All' buttons allow you to either delete selected drains or all pattern drains.
'Drain length' can either be set here or by moving the red circle on the design map.
'Drain Heading' is the direction that the drains run (represented as degrees).
‘Padlock’ button changes the behavior of the copied drains in relation to the original.
locked - This locks ‘Drain Heading’ to ‘Offset Direction’ so if either are adjusted the other will change to match.
Unlocked - ‘Drain Heading’ and ‘Offset Direction’ can be set independently of each other.
'Offset Direction' sets the direction in which copy drains will be created from the original.
'Drain Count' is the number of drain copies you want to add (not including the original drain).
'Drain Offset (Parallel)' is the distance between each line of the copies. (if the padlock is unlocked this will not show in the example until it is manually updated.)
‘Drain Offset (Origin)’ is the set distance between the origin point of each copy.
Press 'Apply' (shown as the pattern drain icon) after parameters are entered.
Once you are happy with the drain paths use the ‘Drain Design’ function to design the profile and cross section of the drains.
# Manual Drains
Create manual drains on a full field elevation surface by placing the drain line along the desired drain path. Tap on a white node to create more purple nodes for nonlinear drain lines. The purple nodes have an elevation height value present in the Design parameters for reference.
- Press Apply to create the drain path.
- Delete drains one at a time or Delete All
- Choose Edit to relocate the drain path.
# Drain Design
Drain paths can be created by:
- Surveying them in the 'Collection' wizard step
- Importing them
- Using the Auto drains tool
- Using the Pattern drains tool
Drain Design allows slope profile and cross section design choices before “burning” (embedding) drains into the map for implementation.
NOTE: If a surface & drain exist, the surface should be designed first & the drain second. If you need to edit drain elevation data you can return to the 'Collect' wizard step to edit the drain line. However you will lose current project designs.
Select a drain and the depth/elevation profile of the drain will show in the plot at bottom right (this chart may need to be dragged up into view). Use the 'AB Reverse' button to make sure your drain is falling from left to right in the profile chart, this will make sure that slope values are all positive and make adjustments a lot easier.
Drain paths can be changed into roads by entering a negative backslope. This will cause the drain design to be inverted.
NOTE: The positioning/layout of drain paths is not considered part of 'Drain Design'. They can be adjusted in the surfacing step for driven drains or in auto drains/pattern drains.
When applying drain designs there are 3 different modes that adjust the path of the drain which are Linear fit, Best fit and Multi fit.
#### **Linear fit**
Creates a single straight plane along the drain path.
'Slope'- is the gradient at which the drain is installed to ensure that water flows in the direction you want.
'Offset'- allows for vertical offsetting of the drain. Setting a positive value will lift the offset creating a fill effect along the entire drain, while a negative value in the offset will lower the design height creating a deeper cut drain.
####
#### **Best fit**
Adjusts the slope to try and follow the natural curve of the field. Similar to multi-fit field design. Cutta Ditch
NOTE: Best-fit in drains is equivalent to Multi-fit in full field design. This incongruity comes from a desire to try and match the naming conventions of the John Deere SWP+ product (which is superseded by T3RRA Cutta and T3RRA Ditch).
‘Min. Slope’- The lowest gradient of slope you will accept in the drain.
‘Max. Slope’- The highest gradient slope you will accept in the drain
‘Min. Cut’- ensures the design will consistently cut at least this amount.
‘Max. Cut’ sets the maximum depth that the design will cut to and ensures that it never exceeds this point.
####
#### **Multi fit**
Applies both cut and fill, and can be used to remove points of erosion and build up that would cause issues. Best used when maintaining existing drains.
‘Min. Slope’- The minimum allowable gradient of the slope.
‘Max. Slope’- The maximum allowable gradient of the slope.
‘Start Elevation’- The desired elevation point at which the design will begin (at point A). Set to be greater than, equal to, or less than the set value adjusting the start elevation value of the design to be no higher or lower than the set value
‘End Elevation’- The desired elevation of the final point on the design also referred to as (point B). Set to be greater than, equal to, or less than the set value to ensure that the final elevation of the design is not higher or lower than the set value.
NOTE: Multi fit tries to balance the cuts and fills using the start and end elevations. If the design parameters won’t work you will see the message: “Model is too constrained” .
#### **General settings**
These settings are present in all drain design modes.
‘Cut/Fill ratio’ - please refer to definitions in appendix. The following settings and buttons are all constant between all three modes in Drain Design.
'Copy To All' - copy the settings of the currently selected drain to all other drains present in the project. If all drains are likely to require similar parameters this can be a big time saver.
'Backslope' (batter) is the gradient of the drain walls. A higher backslope value means a sharper drop into the drain. If no backslope is desired, leave the 'Backslope' box unchecked. If you wish to make a road, enter a negative backslope value.
"Symmetric' when checked, will mirror the batter design. When unchecked, the batter slope can be changed independently for both sides.
‘Lock Backslope’ is mainly intended to be used when working with drain lines - not full surfaces. Will cause the surface to be ignored and the backslopes will be created to their maximum extent. Note: that the drain bottom will always be burnt in, regardless of the surface elevation. I.e., if you offset a drain up 5m, you would always have a drain bottom burnt in, regardless of if lock backslope is on or off
'Drain Width' allows you to control how wide the bottom of the drain is. The drain bottom is always horizontal. If you want a drain bottom with a defined non-zero cross slope you should manually set the cross slope control on your implement in the ‘Implementation’ stage of operation.
'Cut/fill ratio' allows you to compensate for soil compaction characteristics.
'Apply All' allows you to apply all the drains in the field, not just the drain that is currently selected.
Choosing to apply ‘on elevation’ or ‘on design’ chooses the elevation profile that is used to calculate the designed surface. For example, one drain requires a different design than the others present, you will apply the design ‘on elevation’ to All then select the drain from the drop down and apply a different design ‘on design’ to that drain alone.
NOTE: choosing to design on a design will continue to lower the surface of the drain.
'Reverse' button reverses the profile as it is displayed in the profile view. This also affects how the software designs the profile as the software will always try to slope the design from left to right. The 'Reverse' button reverses the drain direction. It effectively reverses the direction calculations are performed on the drain. This is useful when the drain was surveyed from low to high elevation.
Press 'Apply All' (the image of 3 cogs) to apply all drains at once
Press 'Apply' (the image of 1 cog) to apply only the currently selected drain.
After editing your drains in the surveying step, return to create a new drain design in the 'Design' wizard step. If a surface and drain exist, the surface should be designed first and the drain second.
After designing the drain and applying it, it is “burned” (embedded) into the field surface model. At this point you can begin implementing in the same way you would a normal field design. If you are using a constant depth drain cutting implement you may not be interested in the depth profile. You may want to only rely on the paths for guidance and not elevation control. In this case there is no need to create the drain profile (unless you want to look at the effects of the drains in the rainfall simulation).
Option: Use the [**'Export'**](https://t3rra.freshdesk.com/en/support/solutions/folders/51000450920) button on the wizard screen to export the drain paths to an RCD folder structure (JD Guidance lines). You can export ditch track guidance lines that will steer your tractor on exactly the right path to accurately and efficiently remove your wet areas (John Deere AutoTrac™ required).
Here is a video on **[Drain Design Tools.](https://youtu.be/SdABdEDjHyA?feature=shared)**