2018 SWCS International Annual Conference July 29-August 1, 2018 Albuquerque Convention Center

1. Measured Effects of Conservation
Watershed Scale
2004-2018 Synthesis
From the USDA CEAP Watershed
Assessment Studies

2. 1) A few things we’ve discovered;
2) Planning, Targeting, Outcomes, & Surprises;
3) Something New.

3. Watershed
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SummedTile
0.0
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discharge (y = 0.47 x)
dissolved phosphorus (y =0.43 x)
nitrate-nitrogen (y = 0.59 x)
1:1 line
Columbus, OH
This improved understanding of the
distribution and timing of water and
nutrient sources within watersheds
improves opportunities to target
conservation resources for cost-
effective mitigation.
Six years of research in an Ohio
headwater watershed showed that
tile flows accounted for
47% of water discharge,
43% of dissolved P load, and
59% of NO3-N load.
Although tile drainage is required for
crop production in poorly drained areas,
harmful algal blooms in inland waters
have focused attention on nutrient
delivery to streams and lakes.

4. Columbus, OH – EQIP reduces
Atrazine in Columbus drinking water
• The Upper Big Walnut Creek
Water Quality Partnership
was established to address
high atrazine concentrations
in Columbus drinking water
supplies
• The EQIP program successfully
reduced Atrazine in Columbus
drinking water
• $2.73 saved for every $1
spent on NRCS 595 pest
management
• Atrazine concentrations
were reduced below
drinking water thresholds

5. • Millions of $s are spent
on brush removal
programs to increase
area available for
livestock grazing.
• But additional benefits
may also accrue from
these practices.
• A realistic 20% redcedar
encroachment within
the North Canadian
River basin is estimated
to reduce stream
discharge into Oklahoma
City’s Overholser
Reservoir by 8.5 m3 s-1.
• This amount translates
to ~27% of OKC’s current
water demand.
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StreamDischarge(m3s-1)
Redcedar Encroachment
Watonga Calumet El Reno Yukon
Transpiration Study
Transpiration(Ld-1)
Starks et al. 2011. Rangeland Ecol & Mgt. 64(2):178-186.
Starks et al. 2014. Envt & Nat. Resources Res. 4(3):103-122.
Starks and Moriasi. 2017. JSWC 72(1):12-25.
El Reno, OK

6. Kimberly, ID
80% of flow in the Upper Snake-Rock
Watershed is diverted through canals for
irrigation…creating a potential for
increased sediment and P loading from
irrigation return flow.
14 Mg/year dissolved P
reduction
11,000 Mg/year
sediment reduction
…that have reduced
contaminants returned to
the Snake River.
However, multiple conservation
practices were implemented within
the watershed…

7. Kimberly, ID – Cont’d
In an effort to increase water use efficiency, a ten-year
effort increased sprinkler irrigated acreage from 45 to
60% by 2016.
However, the 10-year increase has not resulted in
a significant increase in watershed scale
“efficiency”, because water rights and allocation
schemes dominate water use decisions.

8. Columbus, OH – Ecological Assessment in
Upper Big Walnut Creek
• Grass filter strips widen riparian habitat, but do not restore ecosystem structure in
channelized agricultural headwater streams.
• Quantitative measurements of abiotic and biotic attributes are critical for
ecological assessment.
• Mitigation of agricultural impacts requires long-term implementation that:
• Addresses the primary causes of ecosystem degradation,
• Improves both physical habitat quality and water quality, and
• Targets multiple (rather than single) contaminants.

9.  Using models to assess conservation impact
potential
 APEX and AnnAGNPS models calibrated to the 23.4
km2 Lower St. Francis Basin
 >90% in row crops, primarily rice and soybean
 Cover crops were beneficial from agro-
environmental perspective.
 Source control in spring and late fall can be effective
at reducing the nutrients and sediment in the water.
Jonesboro, AR
Lower St. Francis Basin (LSFB)

10. 10
Holistic
planning
concept
Database for regional consistency
AVOID and CONTROL : Improve soil health within cropped fields to avoid and control pollutant losses by-
Protecting soils from erosion with zero or minimum tillage;
Limiting excess nutrients through rates and timing of fertilizer and manure applications;
Building soil organic matter and rejuvenating compacted soils with intensified crop rotations
Controlled Drainage
where slopes are least
Bioreactors
or small wetlands constructed
above field-tile outlets
Re-Saturated Buffers
Yes No
H A B C
M B C
L C
Close to stream?
Slopesteepness
Yes No
H CZ MSB SSG
M MSB MSB SSG
L DRV DRV SBS
Shallow water table?
Runoffdelivery
Design Types for Riparian Buffers:
CZ Critical Zone -sensitive sites
MSB Multi-Species Buffer
SSG Stiff-Stemmed Grasses
DRV Deep-Rooted Vegetation
SBS Stream Bank Stability
Grassed Waterways where
gullies may form
Contour Filter Strips,
Terraces, Conservation Cover
where slopes are steep
Ditch design: Two-Stage Ditches;
novel practices for detention /
diversion of tile drainage
Runoff Risk Assessment:
Prioritize fields where
multiple erosion control
practices are most needed
Riparian Assessment:
Identify riparian function
by stream reach
Surface Intake Filters or
Restored Wetlands where
depressions occur
IN FIELDS:
Place water control /
filter practices
BELOW FIELDS
Place water
detention / nutrient
removal practices
RIPARIAN ZONE
Place/design
practices for
ecosystem function
and nutrient removal
Perennial crops, & novel
practices to intercept flows
where soils stay wet
Downstream/ In-stream: River restoration
(e.g., pool-riffle structures, re-meandering,
oxbow rehabilitation)
Process for conservation planning to improve water quality in agricultural watersheds using precision technologies
DATA REQUIRED: LiDAR-based digital elevation model, Soil survey, Field boundaries, Land use
CONTROL, TRAP,
and/or TREAT
TILE DRAINAGE SURFACE RUNOFF
Assessments for prioritization
and design of practices
Water detention using impoundments of varying designs
Nutrient Removal
Wetlands
Sediment Detention Basins
Farm Ponds
APPLICATION: Scenario Development/
stakeholder feedback/ implement/ monitor/adapt 5
GIS-based practice siting toolbox
ArcGIS toolbox identifies
locations suitable for
installation of
conservation practices,
and provides
conservation practices
menu to help engage
landowners as decision
making planning partners.
Ames, IA – Decision Support Tools for Selection and Placement of Practices:
Agricultural Conservation Planning Framework

11. Oxford, MS
Integrative placement of conservation
practices requires planning for
management efficiencies.
But reduced sediment
and nutrients loads while
increasing productivity in
Beasley Lake.
Reduced Sediments
Reduced Nutrients
Enhanced Lake Productivity
ChlorophyllaNitrateSuspendedSed.
Which resulted in the
recovery of a viable
fishery in the lake.

12. Columbia, MO
Yet stream bank degradation, the
major source of stream sediment
and phosphorus, has and will
always exist independently of
field management.
Targeting tools are effective for
prioritizing conservation practices.
Although conservation practices
were effective at improving edge-of-
field water quality, variations in
specific practices, implementation
timing, and environmental
conditions masked effects at the
watershed scale.
No-till and cover crops
Rotary harrow
Sediment
Harrow No-till Mulch-till
Atrazine
Harrow No-till Mulch-till
No significant change
in management or
water quality in the
watershed

13. Tifton, GA
However, nutrient
concentrations have generally
remained low, and nitrogen
loading is related to stream
flow but not changes in land
management.
Conservation practice
implementation in the LREW has
increased substantially since
1980, and 65% of fields identified
as at risk for surface water
contamination had appropriate
conservation practices in place by
2008.
Instead, low nutrient loading in
the watershed is attributed to its
dense riparian buffers.
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2009
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1974-
2014
TotalNaverageannualload
(kgha-1yr-1)
Riparian forest buffer
Upland forest
Water
Urban
Crop
Structural conservation practice
Nutrient management practice
Residue management practice
Forest establishment
Minor conservation practice

14. El Reno. OK – Sediment Measurement and Transport Modeling:
Impact of Riparian and Filter Strip Buffers
• Lack of good quality hydrologic and water quality data for model
calibration and validation is one of the main weaknesses to
watershed modeling.
• Scientists in El Reno developed cost-effective methods to collect
stream channel parameterization and evaluation data for modeling
in watersheds with sparse data.
• A case study in the Fort Cobb Reservoir Experimental Watershed
indicated promise for using the Rapid Geomorphic Assessment and
Acoustic Profiling System methods to obtain data that improve
water quality simulations in ungauged watersheds.
• Using the calibrated Soil and Water Assessment Tool (SWAT) model
showed that effect riparian and filter strip buffers can reduce
suspended sediment concentration at the outlet 73%, which has
potential to increase reservoir life.

15. Tifton, GA – Potential Perennial Biofuel Feedstock Production
from Conservation Buffers
Targeted planting of perennial grasses as conservation buffers in the GA coastal plain may
provide from 2.2 to 9.4 Tg yr-1 of biomass and 780 to 3,300 Ml yr-1 of ethanol while reducing
nitrogen delivery to surface waters by 8,100 to 51,000 Mg yr-1.
Coffin et al. 2016. Bioenergy Res. 9:587–600

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SWRIScore
SWAT fall P (mg/L)
(r = -0.73, n=14, p=0.003)
University Park, PA
Predicting conservation benefits
to stream health - Relating SWAT
results to biological sampling.
Courtesy Regan, Brooks (Penn
State) and Veith (ARS)WE-38 stream
reaches
Conservation practices
Stream Wetland Riparian Index correlated
with SWAT modeled fall P

17. Cienega Creek Watershed (CCW)
CEAP Assessment
(ARS-SW Watershed Research Center, NRCS and U. Arizona)
• Cienega Creek Watershed (CCW) – SE AZ; 198 mi2
• Ephemeral – sediment and erosion are primary
concerns
• High climate viability, droughts common (severe
drought 2002 - 2006)
USFS – 41%
Private – 24%
State – 23%
BLM – 12%
Ownership
• Assessment: part of USDA Agency Priority Goal (APG)
• Pre-Conservation Scenario (1992 prior to substantial
conservation spending)
• Cons. Practices (brush removal, prescribed grazing -
fencing, water points, rotations; stock ponds;
prescribed burns)
• Post-Conservation Conditions (2006)
• Use AGWA/K2/RHEM with design storms
• Use NRI & remote sensing data to estimate Pre-Cons.
Condition & 2006 RHEM parameters
• Difference Pre- & Post-conservation simulations
across the watershed for 10yr 1 hour design storm

18. Bottom Line
Percent Change in Sediment Yield from Pre-Conservation Condition (‘92) to
(2006) Simulations
HUC – 12 Boundary
0 – 10 % INCREASE
25 – 30 % decrease
40 – 50 %
decrease
0 – 10 % DECREASE
n = 3577
hillslopes
• Conservation spending and management adaptation maintained and in areas
improved range condition through a severe drought
• Impact: “USDA is now adapting water quality activities to include the
recommendations and lessons learned from this APG.” (Cienega Ck. & St.
Joseph CEAP assessments - USDA Strategic Plan FY2014-2018)

19. Beltsville, MD – Measuring Groundwater Lag Time using Chiral MESA
Fertilizer N Metolachlor
Root
Zone
Vadose
Zone
NO3
- formation and
uptake by crops
Metolachlor
degradation to MESA
NO3
- leaching and
denitrification
MESA leaching
NO3
-
+ MESA move to surficial groundwater
Influenced equally by mixing
Chemical
Application
to Fields
*
NO3
- Metolachlor
Root
Zone
Vadose
Zone
NO3
- uptake by crop Metolachlor degradation to MESA
NO3
- leaching and
denitrification
MESA leaching
NO3
- + MESA move to surficial groundwater
Influenced equally by mixing
Chemical
Application
to Fields
phillipmartin.info
*
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Demonstrated first order
watershed kinetics
MRT
Integrative passive
sampling of streams
Formation of chiral MESA and nitrate in cropland
R² = 0.9155
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Nitrate-N(mg/s)
MESA (μg/s)
MESA as a conserved transport analog
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Opportunity for improving
model resolution.
Pilot studies underway at
multiple CEAP watersheds.