Jill A. Kostel, The Wetlands Initiative, Chicago, ILJim J. Monchak, The Wetlands Initiative, Chicago, ILRon L. Bingner, USDA/ARS, National Sedimentation Laboratory,

Oxford, MS

EVALUATION OF NUTRIENT REDUCTIONS FOR POTENTIAL WETLAND LOCATIONS USING THE WETLAND AND BUFFERS FEATURES OF ANNAGNPS

USGS SPARROW model (Robertson et al., 2009):

Illinois #1 TN and TP flux

Illinois River-Lake Senachwine 23rd for TN delivered

83rd for TP delivered

ILLINOIS RIVER WATERSHED

Land Cover 92% agriculture

77% cultivated crops

BBC Watershed Plan 1,680 Mg (mt) TN/yr

60 Mg TP/yr

281,000 tons sediment

Watershed Reduction Goals 58% TN

43% TP

58% sediment

BIG BUREAU CREEK WATERSHED

CONSTRUCTED WETLANDS

Nutrient Management & Nutrient Reduction Practices

Sour

ce: U

SDA

ARS

Sour

ce: U

SDA

ARS

Constructed Wetland for Tile Drainage Wetland positioning and size key to nutrient removal Positioned to capture high nutrient loads Sized to allow adequate residence time

(wetland area : watershed area - 0.5 – 5%)

Role of Constructed Wetlands in a Nutrient Credit Trading Program

OBJECTIVES

Develop a methodology to identify potential wetland sites in the Big Bureau Creek watershed based on a conservative set of design criteria

Determine baseline nutrient loadings using the Annualized Agricultural Non-Point Source (AnnAGNPS) pollution model

Evaluate the potential wetland sites for nutrient reduction using the AnnAGNPS pollution model with enhanced wetland and buffer features

LIME CREEK SUBWATERSHED MANUAL

Manual method utilized by USDA ARS using 1 m LiDAR data

Total Wetland Area = 96 acresAverage Wetland Size = 8.5 acresTotal Wetland & Buffer Area = 295 acresAverage nitrogen removal = 48%

Tomer, M.D., Crumpton, W.G., Bingner, R.L., Kostel, J.A., and James, D.E. 2013. Estimating nitrate load reductions from placing constructed wetlands in a HUC-12 watershed using LiDAR data. Ecological Engineering 56: 69-78

BBC WATERSHED – SEMI-AUTOMATED

2. Calculate Watershed Position

1. Locate Preliminary Areas of Interest

BBC WATERSHED – SEMI-AUTOMATED

3. Converts Areas of Interest into Impoundment Points

BBC WATERSHED – SEMI-AUTOMATED

4. Convert Impoundment Points into Wetland/Buffer Areas

Design Specifications: Wetted area = 0.9 m above ditch height Buffer area = 2.4 m above ditch height Wetland Area : Contributing Area = 0.1 6.0% Extended Range from typical 0.5 – 5.0%

BBC POTENTIAL WETLAND SITES

Total Number of Wetland Complexes = 80

Total Wetland Area = 225 ha

Range of Wetland Sizes = 0.14 - 38.7 ha

Total Wetland & Buffer Area = 351 ha

Range of Wetland & Buffer Area = 0.54 – 46.5 ha

Area : Total BBC Watershed Area = 0.3%

% of Runoff of BBC Watershed = 23%

Annualized Agricultural Non-Point Source Model Version 5.4 Continuous simulation tool based on daily time step (30 years)

Runoff, sediment, and pollutant movement from surface and subsurface flow is tracked through the stream network to the watershed outlet

Watershed response to agricultural management and conservation practices can be evaluated

Model Input (Data) Climate – 30 year daily simulated weather

Topographic – 10 m DEM

Land use – 2009 Illinois Cropland Data Layer

Soil type – USDA Soil Survey Geographic database (SSURGO)

Point sources – Average Design Flow rates and estimated effluent concentrations

ANNAGNPS MODEL

Baseline Results:

Nutrients TN Load = 2,542,400 kg

TN Loss = 20.4 kg/ha

Dissolved N = 72%

TP Load = 60,150 kg

TP Loss = 3.7 kg/ha

Attached P = 56%

Dissolved Inorganic P = 14%

TSS = 100,446 Mg

Point Sources TN = 0.70% increase

TP = 0.66% increase

Seasonal Effects Spring and summer seasons

higher loadings

ANNUAL AVERAGE LOAD DELIVERED

Accounts for the effectiveness of the potential wetland sites to trap water, sediment, and nutrients

Wetland nutrient retention and transformation processes based on current research

Daily time step approach simulates wetland processes for individual precipitation events

Individual wetland impact can be tracked to any downstream point in the watershed

Each practice scenario can be evaluated separately

The wetlands in series, individually within series, and independent of other wetlands can be evaluated

ANNAGNPSWETLAND & BUFFER FEATURE

The 80 potential wetlands plus buffer (351 ha) would reduce the entire BBC watershed TN annual avg load by 14% and TP by 11%.

Dissolved N, primarily NO3-N, accounted for 84% of the TN removed by potential wetlands plus buffer.

Dissolved inorganic P accounted for only 14-17% of TP removed by the potential sites; attached inorganic P accounted for 51-67%.

% nutrient removal is consistent between seasons at the sub-basin level.

The mass nutrient reduction is higher in the spring and summer, corresponding to the higher delivered loads available for removal.

ANNAGNPSWETLAND & BUFFER FEATURE

PRACTICE SCENARIOS

0

2,000

4,000

6,000

8,000

10,000

12,000

0 5 10 15 20 25 300

500

1,000

1,500

2,000

2,500

3,000

0 5 10 15 20 25 30

0

1,000

2,000

3,000

4,000

5,000

6,000

0 5 10 15 20 25 300

200

400

600

800

1,000

0 5 10 15 20 25 30

Wetland 505 Wetland 505

Wetland 573 Wetland 573

Tota

l Nitr

ogen

at W

etla

nd O

utle

t (kg

)

Tota

l Pho

spho

rus

at W

etla

nd O

utle

t (kg

)

Years

Baseline Buffer Only Wetland Only Wetland with Buffer

ANNUAL LOAD DELIVERED-NITROGEN

ANNUAL LOAD DELIVERED-PHOSPHORUS

*

*

**

LIME CREEK NITROGEN REDUCTION

Average Annual Nitrogen Reduction (kg)

Lime Creek Potential Wetland & Buffer Sites

-

4,000

8,000

12,000

16,000

20,000

24,000

566 567 565 564 573 561 580 585 576 574 547 555 556

SYSTEM

*

*

**

*

-

4,000

8,000

12,000

16,000

20,000

24,000

566 567 565 564 573 561 580 585 576 574 547 555 556

* * *

*

*

INDIVIDUAL

-

4,000

8,000

12,000

16,000

20,000

24,000

566 567 565 564 573 561 580 585 576 574 547 555 556

INDEPENDENT

**

*

*

*

*

Annual Average Nitrogen and Phosphorus ReductionTop 20 wetlands plus buffers based on nitrogen reduction (kg/ha)

BBC POTENTIAL SITE EVALUATION

Wetland RatioAHLm/yr

Total nitrogen reduction Total phosphorus reduction

(kg) % (kg/ha) (kg) % (kg/ha)1919 0.13% 272 30,159 59.1 7,455 5,096 54.6 1,260566 0.10% 385 3,699 54.5 5,183 613 67.4 859555 0.19% 187 5,720 67.7 3,769 512 61.4 338574 0.16% 213 13,802 50.8 3,626 1,518 32.5 399

1924 0.13% 270 6,872 22.1 2,788 1,110 20.1 4501136 0.11% 339 3,325 33.8 2,784 322 0.1 270815 0.13% 282 10,019 23.8 2,483 607 10 151160 0.24% 144 15,598 30.9 2,462 1,585 17.5 250

1146 0.20% 174 6,296 8.9 2,397 679 27.7 259832 0.13% 280 2,707 26.6 2,320 242 15.8 208

1730 0.25% 138 1,803 60.5 2,272 250 62.3 3151906 0.16% 212 2,775 31.9 2,220 371 25.3 296567 0.23% 160 1,917 51.2 2,208 296 56.5 341860 0.15% 210 11,634 34.7 2,207 1,034 21.6 196

2142 0.24% 157 3,037 31.9 2,050 427 26.4 2881174 0.14% 235 2,779 35.1 1,981 291 22.9 2082114 0.53% 70 9,814 48.5 1,975 1,013 35 204491 0.15% 218 3,893 42.7 1,921 747 36.9 369

2065 0.48% 69 11,890 50.2 1,910 2,059 41.4 3312130 0.65% 55 15,573 51.4 1,818 2,063 39.5 241585 0.14% 245 1,924 29.3 1,790 124 14.4 116

SITE POSITIONING

Annual Average Nitrogen and Phosphorus ReductionTop 20 wetlands plus buffers based on nitrogen for wetland: watershed ratios (w:w) of 0.5-5.0%

BBC POTENTIAL SITE EVALUATION

Wetland RatioAHLm/yr

Total nitrogen reduction Total phosphorus reduction

(kg) % (kg/ha) (kg) % (kg/ha)2114 0.53% 70 9,814 48.5 1,975 1,013 35 2042130 0.65% 55 15,573 51.4 1,818 2,063 39.5 2412150 0.65% 53 10,250 57.9 1,672 1,352 41.3 220337 0.58% 50 15,044 59.1 1,514 3,092 46.7 311

1960 0.57% 59 13,238 57.2 1,492 1,799 43.5 2032063 0.80% 44 1,857 72.2 1,473 333 77.8 2642151 0.53% 62 2,167 52 1,345 466 44.5 289561 0.68% 53 11,576 54.8 1,319 787 28.3 90556 0.80% 46 3,406 73.4 1,191 289 66 101

1600 0.67% 48 9,261 65.6 1,175 1,170 47.6 148303 1.00% 32 5,248 81.2 1,161 480 36.4 106512 0.80% 46 3,913 73.3 1,143 604 63.6 177

1117 0.71% 49 2,901 64.5 1,077 181 38.5 672095 0.58% 50 1,974 59 1,034 332 45.8 1741815 0.77% 44 4,389 69.2 989 382 50.7 86505 1.10% 31 5,041 72.5 965 946 61.9 181

1111 1.03% 34 7,055 70.3 952 506 43.6 681926 2.00% 18 13,861 79.7 949 366 11.7 251928 2.90% 13 11,099 94.5 820 1,709 91.6 1261076 0.60% 56 1,404 60.1 815 67 28.7 392022 1.90% 18 5,668 79.8 802 931 70.2 132

A partially automated wetland siting methodology identified 80 potential individual wetland plus buffer sites in areas of higher nutrient loadings.

An AnnAGNPS model with the wetlands and buffers feature was a valuable tool to assess and evaluate the nitrogen and phosphorus removal provided by these 80 potential wetlands site.

Carefully sited and sized constructed wetlands are a key practice in the suite of practice needed to achieve watershed nutrient reductions.

Nutrient credit trading: potential wetland sites have more than sufficient supply of nitrogen and phosphorus to meet the demand set by a set of proposed effluent limits for the 8 point sources.

CONCLUSIONS

Kostel, J. A. et al. 2014. Feasibility Assessment of a Nutrient Credit Trading Market in the Big Bureau Creek Watershed. U.S. Environmental Protection Agency Targeted Watershed Grant WS-00E71101. The Wetlands Initiative, Chicago, Illinois.

Major Project Funders:

USEPA Targeted Watershed Grant

McKnight Foundation

Alliance Pipeline

CONCLUSIONS

Next Steps:

Refine site section methodology and model as better data become available

Advance the adoption of the wetland practice

Proof-of-concept of nutrient removal