Agricultural Subsurface Drainage

USGS Staff: Nancy Baker, Wes StoneGIS Contact: Michael Wieczorek

1. It is impossible to identify the exact location of subsurface drains in the conterminous U.S. (Sugg, Jayne, Naz, Brown)

2. The primary goal is to provide an estimate of the probable percent of agricultural land that may have subsurface drains to facilitate cropping at a National scale (CONUS).

3. This is an exploratory exercise at this point and will build of the work of others as well as incorporate input from various Federal Agencies and Universities.

4. No previous work has been done on the National scale (CONUS) or with the most recent available data at the National scale (SSURGO, CDL, NLCD).

Researchers Land Use Data Soils Data Comments

Jaynes and James, 2004 NLCD, 1992 STATSGODrainage classes,Hydrologic Groups,Land Capability Class

Slope was also included in the analysis23 States in the MidWest and East

Sugg, 2007 NLCD, 1992 STATSGODrainage classes,Hydrologic Groups

Final estimates used drainage class onlyMidWestern Corn belt only

Naz et al, 2009 NLCD, 1992 STATSGODrainage classes

Slope was also included in the analysisHoagland Watershed, IN only

Brown, 2009 NLCD, 2001 SSURGODrainage classes,Hydrologic Groups,Land Capability Class

Slope was also included in the analysisCentral Minnesota only

1. The exact locations of tile drains are incomplete or unknown.2. If row crops are cultivated on poorly drained soils, then artificial drainage likely

exists.3. 1992 remains the most recent complete data set at the county level for CONUS for

Tile Drains.4. No method exists for distinguishing between surface and subsurface drainage.5. No study has been done at the National level (CONUS) or with new data sets

(SSURGO, CDL, NLCD).6. Further exploration may lead to different approaches for different areas as well as

incorporating other data sets.

1. 1992 NRI2. Hydrologic Group3. Drainage Class4. Water Table Depth April June Minimum5. Available Water Storage 0 - 25 cm6. Soil Restrictive layer7. NLCD 20118. Crop Land Data Layer 2013

Approaches/Data Sources

Comparison of Suggs 1992 NRI vs USGS 1992 NRI

Hydrologic Groups and Water Table Depth during April – June ( 100 cm or less)Source Data: SSURGO

Drainage Classes and Soil Restrictive layer ( 25 cm or less)Source Data: SSURGO

Comparison of Hydrologic Groups and USGS 1992 NRI

Comparison of Water table Depth and USGS 1992 NRI

Comparison of Drainage Classes and USGS 1992 NRI

Comparison of Soil Restrictive Layer (25cm) and USGS 1992 NRI

COUNT AG HydGrp SRL25AG DrainageClass WTDEP TILES PCT

43147 1 3 0 1 1 1 53.29883

10587 1 3 0 1 0 1 13.07796

3453 1 3 0 0 1 1 4.265438

677 1 3 0 0 0 1 0.836288

617 1 3 1 1 0 1 0.762171

4589 1 3 1 1 1 1 5.668721

85 1 3 1 0 0 1 0.104999

516 1 3 1 0 1 1 0.637407

5068 1 2 0 0 1 1 6.260423

2550 1 2 0 0 0 1 3.149976

360 1 2 0 1 1 1 0.444702

403 1 2 0 1 0 1 0.49782

61 1 2 1 0 1 1 0.075352

233 1 2 1 0 0 1 0.287821

19 1 2 1 1 0 1 0.02347

13 1 2 1 1 1 1 0.016059

3882 1 1 0 0 1 1 4.795375

2938 1 1 0 0 0 1 3.629266

470 1 1 0 1 0 1 0.580584

966 1 1 0 1 1 1 1.193285

27 1 1 1 0 1 1 0.033353

10 1 1 1 1 0 1 0.012353

11 1 1 1 1 1 1 0.013588

18 1 1 1 0 0 1 0.022235

134 1 0 0 0 1 1 0.165528

89 1 0 0 0 0 1 0.10994

6 1 0 0 1 1 1 0.007412

2 1 0 1 0 0 1 0.002471

17 1 0 1 0 1 1 0.021

2 1 0 1 1 1 1 0.002471

1 1 0 0 1 0 1 0.001235

2 1 0 1 1 0 1 0.002471

80953 100

Leary-Weber Ditch, IN

Blue = Ag land and NRI 1992 Tiles 100%

Brown = All other areas

COUNT TLES100PCT AG HGDOM PCT

80105985 0 0 0

20524670 0 0 1

46669727 0 1 0

47800312 0 1 1

2207636 1 1 0 29.00647

4576273 1 1 1 60.12836

398839 1 0 0 5.240407

428092 1 0 1 5.624767

7610840

TILES100PCT 1 = 100% NRI92, 0 = not

AG 1 = cropland and , 0 = not

HGDOM 1 = COMBO, 0 = not

COUNT AG andTile wtdep < 100 cm hydgrp pct

4998098 1 1 3 65.67

2383244 1 1 2 31.31

150034 1 1 1 1.97

29194 1 0 2 0.38

25421 1 1 0 0.33

18582 1 0 1 0.24

6267 1 0 3 0.08

7610840

AG andTile

1 = cropland and 100% tile (92NRI), 0 = not

wtdep < 100 cm

1 = SSURGO water table during Apr-May-June < 100 cm

hydgrp

1 = AorB, 2 = CorD, 3 = any COMBO

Questions?