Transcript Hydrologic ChangesA Historical Perspective Kevin Kuehner BNC Water Quality Board Tiling on William Sharkey farm, Derrynane Township, LeSueur County.

Hydrologic ChangesA Historical Perspective
Kevin Kuehner
BNC Water Quality Board
Tiling on William Sharkey
farm, Derrynane
Township, LeSueur
County.
Tiling on William Sharkey
farm, Derrynane Township,
LeSueur County.
Extent of Subsurface Drainage(’92)
Channelized Streams & Ditches
Nitrate Losses in Seven Mile
Creek Watershed
Year
FWMC
(mg/L)
Load
(lbs./acre)
2000
17
14
2001
11
39
2002
13
16
2003
19
14
2004
22
19
5-year avg.
16
20
Study Area
Study Area




23,551 acres
“Prairie
pothole”
Poorly drained
clay loam soils
88% row-crop
cultivation
Methods
1.
2.
3.
4.
5.
Photo acquisition
Scanning
Rectification
Cropping and creating a mosaic image
Aerial photo interpretation, mapping
and analysis
Methods

Ten different flights
were used.

1938, 1950, 1555,
1961, 1967, 1978,
1985, 1990, 2002,
2003.
Methods

Pre-settlement
Wetlands
– PLS of 1854
– Soil Survey
– USGS DEM
Rectified 1854 Public
Land Survey Map of
Nicollet County
Methods

2002 crop fields were compared to airphoto interpreted wetlands.

The most common interpretation
methods used were photo tones,
textures, and field pattern contrasts.
Seven Mile Creek Watershed
Nicollet County, Minnesota
Fox Lake
CD29
8
9
10
Research Fields
17
16
!"5
15
#
21
22
29
28
$
$
Site 2
6
!"17
5
8
CD
12
#
36
Mino rshe d 063
ek
4
Nic o llet Twp.
Legend
35
Site 1
e
e Cr
Mil
en
Sev
1
La
ke
25
2
"!
13
58
9
10
11
$
a Rive
r
33
Be lg ra de Twp.
11
26
Minn
32
99
%
g
2
27
O a k L e a f L a ke
US
16
9
31
Gra nby Tw p. Mino rshe d 066
d
Mu
99
%
g
CD 46
36
Nicollet
23
CD13
30
Littl
e
Lak
e
25
St. Peter
Tra v ers e Tw p.
Os h awa Twp.
Mino rshe d 062
!"13
Drinking Water Supply
Management Area
City of St. Peter
11
t
eso
Seven Mile Creek
$
W ater Quality
Monitoring Site
Major Roads
Public Open Ditch
Public Ditch Tile
Site 3
Seven Mile Creek
County P ark
17
16
15
City
CD 24
Seven Mile Creek
W atershed
2
0
2
4 Miles
BN C W ater B oar d_ 200 0
Redtop Farms
Research Fields
W etlands
Fox Lake
1938
Fox Lake
1955
Fox Lake
1968
Fox Lake
1990
Pre-settlement
~11,000 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1851
5,863 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1938
5,104 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1950
4,095 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1955
2,042 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1961
1,662 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1968
1,372 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1978
1,307 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
1985
1938
1985
Altered vs. Natural Drainage
--Public Drainage Ditch = 33
miles
--Public Ditch Tile = 15 miles
Public Drainage Ditch
Private Drainage Tile
--Private Tile Lines = ~ 6001,000 miles
Public Drainage Tile
--96 % of cultivated land is
artificially drained
Unaltered Drainage
Extent of Wetlands by Year
Seven Mile Creek Watershed
-61 a/yr.
10,000
1938-1985
-97 a/yr.
8,000
1985-2003
+14 a/yr.
6,000
4,000
2,000
03
20
02
20
90
19
85
19
78
19
68
19
61
19
55
19
50
19
38
19
00
s
0
18
Wetland Acres
12,000
1,561 acres
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
2003
Site 1
Site 3
Site 2
July 1,2004
Tile Break and
Water Level Control
Structure Location
Functioning Tile
Non-Functioning Tile
County Main
Location to daylight
county main
S
E
W
N
Site 1
Site 3
Acknowledgements






McKnight Foundation
Minnesota’s Clean Water Partnership
Program
USDA-NRCS
MNDOT
Nicollet County Env. Services
Gustavus Adolphus College Interns
Kevin Kuehner
322 S. MN Ave
St. Peter, MN 56082
507-934-4140
[email protected]
BNC Water Quality Board
http:/msu.ed/org/bnc