1. Subsurface (Tile) Drainage Hydrology & Water Quality
Thomas F. Scherer
NDSU Extension Agricultural Engineer
(701)

2. Restrictive Sub-Layer - High Water Table
Runoff

3. Water Table with no Tile Lines

4. Pattern Tiling

5. How Water Flows into Tile Lines
Rain
Runoff
Water Table Level in late July, August and September

6. How Water Flows into Tile Lines
Rain
Runoff
Water Table

7. How Water Flows into Tile Lines
Runoff
Water Table

8. How Water Flows into Tile Lines
Runoff
Water Table

9. How Water Flows into Tile Lines
Water Table

10. Iowa State University Bulletin - 1911

11. Ground Surface
Tile Lines

12. The black dots are when the pump was on and the blue line shows the accumulated rain (scale on right side).

14. ¼ inch DC 966,000 gal/day
3/8 inch DC 1.45 million gal/day

15. 2010 Richland County Tile Flow

16. Richland Site (2010 to 2013)

17. Surface Runoff
3- inch Rain
30 hours

19. Annual Water Balance

20. Annual Water Balance

21. What Have We Learned?
Spring – Tile flows only after frost is out of the ground
Spring and Summer: Tile flows in response to frequent or single large rain events
Fall: Water table is below the tile lines for most RRV soils
Fall: Tile flows only after soil is full below tile lines
Fall/Winter: If we have a wet fall, tile will flow into late December or early January

22. Tile and Shallow Aquifers

23. Tile and Shallow Aquifers

24. What’s in Tile Water?

25. Why is Subsurface Drainage is being Installed in North Dakota?
Excess Precipitation since 1993 and Saline Soils
These salts are particularly troublesome in eastern North Dakota. This map, prepared by NRCS, shows the potential saline areas in the Red River Valley. These problem soils are also in southern Manitoba. 25

26. 2008 Phase I Fargo Watersheds: Elm River Maple River Rush River
18 Sites:
16 gravity and 2 lift stations
Weekly samples from April to December
Roxanne
Lori Clark
Darin Eisinger
Fargo
19 sites originally
18 by the time we were done 26

27. Water Quality Parameters Measured in Subsurface Drainage Water
Each Sample – 40 analyses
Total Dissolve Salts (TDS)
Major minerals
Minor minerals
Heavy metals pH
No Bacteria or Organic Matter Testing
We know from previous studies what you can expect from some of these, but what about the salts in predominantly clay soils? 27

28. This drinking water purposes this water is considered objectionable because it exceeds the secondary standard of 500 mg/l. Secondary standards means that while it is not a health issue the water may be objectionable for taste. Sea water comes in at 30,000mg/L.
The majority of high quality ground water (less than 2,000 mg/L TDS) in North Dakota is contained within glacial drift aquifers. These aquifers are generally composed of sand and/or gravel deposited by glacial activity. Most of the glacial drift aquifers are located at or near the surface, though some are buried by till deposits from subsequent glacial advances. Ground water quality in the glacial drift aquifers generally ranges from as low as 200 mg/L TDS to several thousand mg/L TDS. Some areas that discharge ground water mainly through evapotranspiration processes may have TDS in excess of 10,000 mg/L.
I have marked on this graph the limits set for livestock and irrigation. 28

31. 319 Funded Project Tile Drainage Water Quality/Quantity 2009 – 2013
Grand Forks
319 Funded Project
Tile Drainage Water
Quality/Quantity
2009 – 2013
Fargo

32. 2009-2013 Sampling Total Dissolved Solids
Silty Clay Loam
Saline
Silty
Clay
Silty
Clay
Loam
Silty
Loam
Saline
Silty
Clay
Loam
Silty
Clay
Fine
Sandy
Loam
Loamy
Sand

33. 2009-2013 Sampling Nitrate-Nitrogen
Corn
Soybean
Wheat
Corn
Soybean
Corn
Soybean
Wheat
Corn
Soybean

34. 2009-2013 Richland County TDS and Nitrate-Nitrogen

35. 2009-2013 Total Phosphorus Total Phosphorus
Percent of Samples > 0.1 mg/l
57% 6% 7% 3%
28%
17%
20%
21%

36. 2009-2013 Sampling Sulfates (SO4)
Sulfate Comprises > 65% of TDS at 5 sites (higher clay content soils)
3 other sites: 51, 35 and 20%

37. Thank you
for your attention!