![Page 1: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/1.jpg)
Wetland Hydrology Criteria Wetland Hydrology Criteria and Field Indicatorsand Field Indicators
![Page 2: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/2.jpg)
Criteria for Wetland Hydrology
Corps Manual:
Area is inundated or saturated to the surface for at least 5% of the growing season in most years
![Page 3: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/3.jpg)
Criteria for Wetland Hydrology National Food Security Act Manual:• Area is inundated for at least 7 consecutive days
during the growing season in most years, or• Saturated at or near the surface for at least 14
consecutive days during the growing season in most years. Soils may be considered saturated if the water table is within:– 0.5 ft of the surface for sands– 1.0 ft of the surface for all other soils
![Page 4: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/4.jpg)
Growing Season
The portion of the year when soil temperature (measured 20 inches below the surface) is above biological zero
(41 °F or 5 °C).
![Page 5: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/5.jpg)
May be approximated by:
Growing Season
• Period when air temperatures are above 28 °F at a frequency of 5 years in 10
• Data sources:– Soil survey reports– WETS tables
![Page 6: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/6.jpg)
Kinds of Hydrologic Data
Tide and stream gages
![Page 7: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/7.jpg)
Kinds of Hydrologic Data
Groundwater wells
![Page 8: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/8.jpg)
Kinds of Hydrologic Data
Repeated aerial imagery
19851986
19871988
1989
![Page 9: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/9.jpg)
Sources of Hydrologic Data
• Corps District offices• U.S. Geological Survey• National Oceanic and Atmospheric
Administration• Natural Resources Conservation Service• State, county, and local agencies• Developers and consultants
![Page 10: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/10.jpg)
Evaluating Wetland Hydrology
Because hydrologic data are often unavailable for project sites, most wetland hydrology decisions are based on indicators
![Page 11: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/11.jpg)
Hydrology Field Indicators
Primary Indicators• Observation of inundation• Observation of soil saturation• Water marks• Drift lines• Sediment deposits• Drainage patterns in wetlands
![Page 12: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/12.jpg)
Primary Indicators
Direct observation of inundation
![Page 13: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/13.jpg)
Primary Indicators – Soil Saturation COE Manual -
Condition in which all easily drained pores between soil particles are temporarily or permanently filled with water.
![Page 14: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/14.jpg)
Saturation
• Saturation– Water content definition – when all pores are filled with
water, except those that contain entrapped air• Measured indirectly by tensiometers or on a weight basis• Field observation not reliable nor scientific• Is the basis of the word “saturation” in the COE 87 Manual• The only way the capillary fringe could ever be “saturated”
– Water pressure definition – when its water has a pressure that is equal to or greater than atmospheric pressure
• Field observation of the water table
![Page 15: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/15.jpg)
Water Table The upper surface of
groundwater, or the level at which water stands in an unlined borehole.
Water is at atmospheric pressure or greater
![Page 16: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/16.jpg)
Capillary Fringe
A zone immediately above the water table in which water is drawn upward by capillary action.
Water is at less than atmospheric pressure.
![Page 17: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/17.jpg)
Capillary Fringe
• "the soil is saturated to the surface at some time during the growing season of the prevalent vegetation." (Paragraph 26.b.3), and
• "the depth to saturated soils will always be nearer to the surface due to the capillary fringe." (Paragraph 49.b.2).
• Estimates of capillary fringe are based on soil texture alone*
![Page 18: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/18.jpg)
0 50
Water Table
Zone of Tension Saturation
% of available pore space filled with water
25
Hei
ght a
bove
the
wat
er t
able
(cm
) or So
il m
oist
ure
tens
ion
/ su
ctio
n
5
25
Hypothetical Capillary Fringe
![Page 19: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/19.jpg)
Capillary Fringe - Reality
• Thickness of the cap. Fringe depends on:– Size of the largest pores
• Texture, structure, OM
– Whether water table is rising, falling, or static
– Whether plants are extracting water from the soil
![Page 20: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/20.jpg)
Primary Indicators
Water marks
![Page 21: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/21.jpg)
Primary Indicators - Drift Lines
![Page 22: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/22.jpg)
Primary Indicators
Sediment deposits
![Page 23: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/23.jpg)
Primary Indicators
Drainage patterns in wetlands
![Page 24: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/24.jpg)
Hydrology Field Indicators
Secondary Indicators(2 or more required)
• Oxidized root channels• Water-stained leaves• Local soil survey data• FAC-neutral test*
* Not used by New England COE
![Page 25: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/25.jpg)
Secondary Indicators
Oxidized root channels (rhizospheres)
Iron plaque
![Page 26: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/26.jpg)
Secondary Indicators
Water-stained leaves
![Page 27: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/27.jpg)
Secondary Indicators
Local soil survey data
![Page 28: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/28.jpg)
Secondary IndicatorsFAC-neutral test
(OBL + FACW) > (FACU + UPL)
![Page 29: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/29.jpg)
Other
• Fe discharge• Spagnum moss• Biological• ???
![Page 30: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/30.jpg)
Meteorological Considerations
• Did it rain immediately before the site visit?
• Has long-term precipitation been “normal”?
To interpret hydrologic data or field observations, one must consider antecedent precipitation
![Page 31: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/31.jpg)
Evaluating Normal Rainfall
Grand Island, NEHow representative of normal conditions are hydrologic data collected in:• May 1991?• August 1991?
![Page 32: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/32.jpg)
Normal Precip, Keene, NHApril – October 2003
0
1
2
3
4
5
6
April June August October
Normal HiActualNormal Lo
![Page 33: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/33.jpg)
Evaluating Normal Rainfall
• USDA National Water and Climate Center• Analyze monthly precipitation data from
>8,000 National Weather Service stations• Based on a standard 30 years of rainfall data• Provide monthly and annual thresholds for:
– Below normal rainfall (lowest 3 years in 10)– Above normal rainfall (highest 3 years in 10)
WETS tables
![Page 34: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/34.jpg)
EVALUATION OF ANTECEDENT PRECIPITATION FROM 30-DAY ROLLING TOTALS
12Sum of c. 5
11below1Feb. 043rd 30 days prior
21below2March 042nd 30 days prior
93above3April 041st 30 days prior
Rating ValueProduct of c. 3 * c. 5
Precip. Level weighting factor
Block “Normality”above normal, below normal, or normal
RecencyWeighting Factor
Dates of Block(30,60,90 days prior)
Prior 30-day BlockSite Visit:4/30/04
If sum is 6 – 9, then prior period has been drier than normal. If sum is 10 – 14, then prior period has been normal. If sum is 15 – 18, then prior period has been wetter than normal
![Page 35: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/35.jpg)
Further Information
• “Accessing and Using Meteorological Data to Evaluate Wetland Hydrology”
• “Guidelines for Conducting and Reporting Hydrologic Assessments of Potential Wetland Sites”
• “Installing Monitoring Wells/Piezometers in Wetlands”
– http://www.wes.army.mil/el/wrap/techtran.html#reports
![Page 36: Wetland Hydrology Criteria and Field Indicators · Criteria for Wetland Hydrology ... • USDA National Water and Climate Center ... >8,000 National Weather Service stations • Based](https://reader033.vdocuments.us/reader033/viewer/2022043008/5f99c62957c89b5ca021e553/html5/thumbnails/36.jpg)
Data Sources on the Web
• WETS tables– http://www.wcc.nrcs.usda.gov/water/wetlands.html
• USGS Real-Time Water Data– http://water.usgs.gov/realtime.html
• USGS Historical Stream Flow Data– http://h2o-nwisw.er.usgs.gov/nwis-w/US/