Nebraska’s Water … · Water Management Overview Nebraska’s Water Policy History • Drought as a driver of change • Nebraska history of increasing accountability • 1895

10/31/2019

© 2019 University of Nebraska –Lincoln 1

Steve Melvin, Extension Educator

Nebraska Extension

Merrick County

Katie Pekarek, Extension Educator

School of Natural Resources

Daran Rudnick, Ag Water Management Specialist

Biological Systems Engineering

The Scope of Nebraska’s Water Resources

Outline

• Water Quantity Overview

• Surface Water/Groundwater

• Irrigation Water Use

• Irrigation Equipment

• Nebraska’s Water Governance

• Nebraska Water Management Overview

• Water Quality Overview

• Surface Water/Groundwater

• Management Areas

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Water Demand from Various Sectors

Climate

Industry

Hydrologic Cycle

http://www.isws.illinois.edu/docs/watercycle

• On a global scale the volume of water is constant and most of the water is recycled.

• Water foot prints and water conservation don’t make sense at that scale.

• Conservation is much more relevant at the local watershed scale.

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From Nebraska Dept. of Natural Resources

Precipitation Changes About 1 Inch For Every 25 Miles East-west

Nebraska’s Water Supply(average conditions)

~ 88% of Precipitation Goes to Evapotranspiration

~ 6% of Precipitation Goes to Increased Stream Flow

~ 8% of Evapotranspiration due to Irrigation

~ 18% of Evapotranspiration from Farmland due to Irrigation

ET = 19.9 inches / yr

Precipitation = 22.6 inches / yr

Surface Water Inflow = 0.9 inches / yr

Surface Water Outflow = 2.3 inches / yr

Other Consumptive

Use = 1.3 inches / yr

Source: USGSNational Water Summary 1987 – Water Supply and Use: Nebraska

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Annual Lake Evaporation , inches

Growing Season ET for Corn (May 1-September 15)

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Nebraska Agriculture

Source: The United States Department of Agriculture – National Agricultural Statistics Service (USDA-NASS) 2012 Census.

• Statewide: ~18.8 million acres of harvested cropland

• Statewide: ~38% of total land area is harvested cropland

Nebraska Agriculture

Source: The United States Department of Agriculture – National Agricultural Statistics Service (USDA-NASS) 2012 Census.

• Statewide: ~9.3 million irrigated acres (Harvested Cropland)

• Statewide: ~44% of harvested acres are irrigated

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Ground Water Wells

Irrigation

Well

IRRIGATION DEVELOPMENT

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Registered Irrigation Wells December 2018

Nebraska Pivots

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Nebraska: Nitrate Groundwater Contamination

Recorded concentration of nitrate (NO3) in irrigation wells from 1974 to 2012 (Quality-Assessed Agrichemical Database for Nebraska Groundwater, 2013).

EPA Maximum Contamination Level (MCL) is 10 ppm

The Central Nebraska Public Power and Irrigation District

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Surface Irrigation Districts Managed by the United States Bureau of Reclamation

Groundwater-Level Changes in Nebraska - Predevelopment to Spring 2018

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EVAPOTRANSPIRATION (ET) = loss of water through evaporation (from soil, open water and plant canopy surfaces) and plant transpiration.

EVAPOTRANSPIRATION (ET)

ET Depends On Weather Conditions

• wind

• solar radiation

• humidity

• temperature

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ET Depends on Plant Size and Density

LEAF AREA INDEX (LAI) =amount of surface area on top of leavescompared to underlying land area

LAI IS ABOUT 1.0

LEAF AREA

LAND AREA

ET reaches maximum rate when LAI is about 3.0

Consumptive Use

That part of water withdrawn that is:

• evaporated,

• transpired by plants,

• incorporated into products or crops,

• consumed by humans or livestock, or

• otherwise removed from the immediate water environment.

Also referred to as water consumed

From USGS

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Consumptive Use vsIrrigation Pumping

Consumptive Use vsEvapotranspiration

Consumptive Use

Relation Between ET and Consumptive Use

ET irrigated

ET dryland

Consumptive Use OfIrrigation Water

Consumptive Use = Consumptive Irrigation Requirement if crop is irrigated to avoid stress and produce a “full” yield.

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Water Balance for Good Center Pivot –Holdrege Area

In-Field ET Increase

78%

Surface Evaporation

Loss9%

Deep Percolation

13%

Consumptive Use Fraction = 87%

Consumptive Use About 74.6%

In-Field Evapotraspiration

70.0%

Evaporative Loss from Pit

2.2%

Evapotranspirationfrom Wetted

Waterway2.5%

Deep Percolation In-Field and In-

Reuse25.4%

Water Balance At Full Yield for Furrow Irrigated Field

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Water Distribution is Key

1. Water is not where “WE” want it. 2. How much ground water is useable?

• Streamflow is affected because the water table drops and less water gets to the stream.

• Downstream demands may trump local ground water use.

• Renders some of the aquifer to be unavailable.

Extensive Research

Nebraska:

• Clay Center: Irmak (2015a,b) & Rudnick et al. (2016)

• North Platte: Payero et al. (2008, 2009) & van Donk et al. (2012)

• Scottsbluff: Spurgeon and Yonts (2013)

Colorado:

• Akron: Benjamin et al. (2015) & Schneekloth et al. (2012)

• Yuma: Al-Kaisi and Yin (2003)

Kansas:

• Colby: Lamm et al. (1995, 2014)

• Tribune: Schlegel et al. (2012)

• Garden City: Klocke et al. (2011) & Kisekka et al. (2015, 2016)

Texas:

• Etter: Hao et al. (2015a,b)

• Lubbock: TAWC (2017)

• Bushland: Baumhardt et al. (2013), Musick and Dusek (1980),

Howell et al. (1995), & Schneider and Howell (1998)

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Siphon Tubes

Tow Line

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Furrow Irrigation

Surge Valve

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Fixed Solid Set Sprinkler

Center Pivot

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How Pivots Move

Do not park anything in the pivot tracks

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Uniform to Variable Rate Irrigation

Depending on system and controller center pivots can be managed uniform, in sectors, bank of sprinklers, or individual sprinklers.

Uniform Irrigation Fixed Zone Control Irregular Zone ControlSector/Speed Control

Variable Rate Irrigation Technology (VRI)

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Remote Control and Monitoring of Center Pivots

• Control pivots, end guns, injectors, and pumps

• Monitor and record water usage

• Keep up-to-date with real-time alerts

• Manage groups of equipment and people

• Run reports

Chemigation with a Center Pivot

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Chemigation System Layout

Wheel Track Issues

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Zimmatic NFTrax Wheels

Dragon Line: Precision Mobile Drip Irrigation

Source: http://dragonline.net

Dragon Line

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SDI Install

SDI

• SDI has about 250 miles of drip tape in a 160 acre field

• Over 20,000 connections

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Nebraska’s Water Governance

• Surface Water

• Prior appropriation – “first in time, first in right”

• DNR – administering surface water, issuing permits, tracking usage, and in times of shortage issuing “cease withdrawals”

Surface Water

First in Time, First

in Time

Nebraska’s Water Governance

• Groundwater

• Correlative Rights

• In 1957 the Unicameral passed legislation requiring the registration of all irrigation wells.

• Today NRDs locally manage permits for groundwater wells

• Well registration in a statewide database

Groundwater

Correlative Rights

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Water Management Overview

Nebraska’s Water Policy History

• Drought as a driver of change

• Nebraska history of increasing accountability

• 1895 – Surface water rights & doctrine of prior appropriation

• 1972 – Creation of NRDs

• 1975 – Groundwater Management Act

• 2004 – LB 962 for collaboration of Integrated Water Management Plans

Groundwater Quality

Who Monitors Ground Water in Nebraska?

• Natural Resources Districts (23)

• Nebraska Department of Agriculture

• Nebraska Department of Environmental Quality

• Nebraska Department of Health and Human Services

• Public Water Suppliers

• University of Nebraska-Lincoln

• United States Geological Survey

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Who Manages Nebraska’s Water?

Determine Source of Pollution

Point Source Nonpoint Source

Surface Water Quality

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Surface Water Quality - Monitoring

• Ambient Stream Monitoring

• 100 sites statewide – Monthly

• Monitoring

• 12 months per year• TSS, chloride, ammonia, nitrate+nitrite, kjeldahl

nitrogen, total phosphorus, water temperature, dissolved oxygen(DO), pH, conductivity, turbidity, stream discharge

• monthly pesticides, May-Sept.• Atrazine, acetochlor, metolachlor

• quarterly metals, Jan, Apr, July, Oct, • Se, Hg, Na, Mg, Ca As, Ca, Cr, Cu, Pb, Ni, Ag, Zn


• Basin Rotation Monitoring

• 35-45 sites per year (Map) – 6 year schedule

• Weekly, May –Sept (22 weeks)

• TSS, chloride, ammonia, nitrate+nitrite, kjeldahl nitrogen, total phosphorus

• water temperature, dissolved oxygen (DO), pH, conductivity, turbidity, stream discharge

• weekly pesticides, May-June

• Atrazine, acetochlor, metolachlor

• E. coli

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• Basin Rotation

Public Beach Monitoring

• Public Beaches – 51 sites

• Weekly, May 1 – Sept. 30 (22 weeks)

• Bacteria, microcystin

• Partners assistance

• Weekly results posted http://dee.ne.gov


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Other Monitoring

• Ambient Lake• 45 lakes• Monthly, May – Sept.

• Fish Tissue • 30-60 lakes and streams• typically 50-120 fish samples• Basis of fish consumption warnings

• Stream Biological ~ 30-40 sites• Habitat assessment• Bugs, fish• Field parameters


Next Integrated Report to be submitted to EPA April 1, 2020

Surface Water Quality – The Results

• Integrated Report 2018

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181

136

85

50

16 15

020406080

100120140160180200

Surface Water Quality - 2018 Most Common Lake Impairments

184

59

23 19 110

20406080

100120140160180200

Surface Water Quality - 2018 Most Common Stream Impairments

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Surface Water Quality - Actions to Solve SW Quality Problems

• TMDL – Total Maximum Daily Load• Pollutant Loads from

• Point sources• Nonpoint sources• Natural/background

• Permit updates/revisions – NPDES permits• Reissued every 5 years• Watershed (Basin) Management Plans• Incorporate TMDL• Nonpoint source pollution focused• Community Based Planning

Surface & Ground Water Quality Management Plans

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BGWMA

Missouri R.

Creighton

Bazile Ground Water Management Area

Ground Water Quality – Making Improvements

• Ground water nitrate analysis

• Soil analysis for nitrogen

• Manure analysis for nitrogen

• Use nutrient analysis in calculating

application rate

• Fall/winter fertilizer application Prohibited.

Typical Ground Water Management Plan BMP Requirements

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• Issue permit for drilling new wells > 50 gpm

• Use of nitrogen inhibitors

• Annual crop report


• Split fertilizer application

• Irrigation scheduling/management

• Farmer education/certification every 4 years


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Modified by Dave Miesbach.

Ground Water Quality – Where does Ground Water come from?

Ground Water Wells

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Ground Water Quality – Quality-Database for Nebraska Groundwater

• Ground Water Quality – Quality- Assessed Agrichemical Contaminant Database for Nebraska Groundwater

• Provides Groundwater Monitoring Results for Agricultural Compounds in Nebraska to the public.

• Provides an indicator of the methodologies used in sampling and analysis for each of the results.

Ground Water Quality

• Types of Wells Sampled

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Ground Water Quality

Ground Water Quality – Nitrate Trends

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Trend:

1998-2017

Median of

Most Recent

Nitrate-N

By Township,

1998 - 2017

Median of Most Recent Nitrate-N By Township, 1998 - 2017

Community Public Water Supply Systems with Requirements for Nitrate

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Ground Water Quality - Nitrate and Health

Environmental NOx Cycling

In Vivo NOx Cycling

Excess Nitrate InputsProtective Action – Aides Heart

Development

Protective Action – Decrease Blood Pressure (Vasodilation)

Alteration of Nerve Activity

Carcinogenic Activities

Methemaglobinema (Blue Baby Syndrome, not enough Oxygen)

Hormone Disruption

Protective Action - Antimicrobial

Ground Water Quality - Nitrates, Atrazine & Health

• Nitrosatable Compounds

Atrazine and nitrate are the two most prevalent drinking water contaminants in Nebraska.

Nitrate Wells Sampled (1977-2014)18,843 or 25,811(73%) were positive at > 2ppm

Atrazine Wells Sampled (1977-2014)916 of 4311 (21%) were positive

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• WHY IS THIS THE QUESTION? WHY ATRAZINE AND NITRATE? WHY NITROSATABLE COMPOUNDS

• Atrazine’s chemical structure contains a secondary amine which can nitrosate in the presence of nitrite in an acidic environment such as the human stomach, forming a nitrosamine, N-nitrosoatrazine.

• Many nitrosamines are carcinogenic in animal models.

• Nitrosamine toxicity is greater when the exposure is chronic vs. acute and exposure to nitrate and atrazine is probably chronic .


• Non-Hodgkins Lymphoma (NHL) Nebraska Study

• NHL risk is 2.5 times higher for subjects exposed to nitrate and atrazine in drinking water compared to subjects not exposed.

• Nitrate & Atrazine Nebraska Birth Defects

• Nebraska rate 2008-2014: 7.9% of all live births (National 3.3%)

• There is a positive correlation between the presence of Nitrosatable Compounds in Nebraska

• There is a positive correlation between the presence of Atrazine in Nebraska

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• Drinking Water Protection Plans and Wellhead Protection Plans

• Voluntary

• “Grass-Roots” dependent

• Grants to help planning and implementation

Source Water Protection & Wellhead Protection

• Steve Melvin, Extension Educator

• Merrick County

• Katie Pekarek, Extension Educator

• School of Natural Resources

• Daran Rudnick, Ag Water Management Specialist

• Biological Systems Engineering

The Scope of Nebraska’s Water Resources

Documents

Nebraska’s Water … · Water Management Overview Nebraska’s Water Policy History • Drought as a driver of change • Nebraska history of increasing accountability • 1895