NONPOINT SOURCE SUCCESS STORY
Implementing Best Management Practices Decreases Nutrient and Turbidity
Levels in Joe s Bayou
Waterbody Improved Runoff of fertilizer and sediment from agricultural lands
caused high turbidity and low dissolved oxygen in Joes
Bayou. As a result, the Louisiana Department of Environmental Quality (LDEQ) added
Joe's Bayou to the 1990 Clean Water Act (CWA) section 303(d) list of impaired waters for
failing to attain its fish and wildlife propagation (FWP) designated use. Local landowners
decreased the runoff of fertilizer and sediment by implementing agricultural best
management practices (BMPs) within the watershed. Turbidity, nitrogen and phosphorus
are trending downward. LDEQ is hopeful that, with ongoing implementation, turbidity will
continue to decline and dissolved oxygen levels will meet the water quality standard.
Problem
Joe's Bayou (LDEQ subsegment 081002) is in
Louisiana's Ouachita River Basin. The bayou flows
for 78 miles through East Carroll Parish and emp-
ties into Bayou Macon. Land use/land cover in the
Joe's Bayou subsegment is primarily agricultural;
soybeans, corn, and cotton are the primary crops
(Figure 1). The suspected source of impairment in
Joe's Bayou was runoff of sediment and fertilizer
from agricultural fields. This runoff threatened the
health of fish and wildlife in Joe's Bayou.
Louisiana's water quality standards for FWP in Joe's
Bayou require that no more than 10 percent of sam-
ples collected on a monthly or near-monthly basis
for dissolved oxygen may be below 5.0 milligrams
per liter (mg/L). Samples collected in 1990 showed
that two of the eight values for dissolved oxygen
were below the standard. Currently, Joe's Bayou
has no numerical criteria for turbidity; however, high
turbidity values were also a concern. Therefore, in
1990, Joe's Bayou was listed as impaired for FWP
due to turbidity, dissolved oxygen, nitrogen and
phosphorus.
The nitrogen and phosphorus impairments were
listed as a result of the causal relationship between
excess fertilizer runoff and falling oxygen levels:
high nutrient loading facilitates algal growth and
oxygen depletion as the algae dies off and decom-
poses. The turbidity impairment was also suspect-
ed to be from the excess fertilizer runoff.
Joe's Bayou
Subsegment 081002 / Land Use
Y
V
0 0751 5 3 4.5 6
Figure 1. Land use/land cover map of Joe's Bayou.
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Project Highlights
Results
LDEQ developed a watershed implementation
plan for Joe's Bayou in 2005 and updated it in
2011 and 2012. As a part of this plan, the Louisiana
Department of Agriculture and Forestry (LDAF)
used CWA section 319 funds to reduce sources
of nonpoint source pollution in the Joe's Bayou
watershed. Beginning in 2006, LDAF and the U.S.
Department of Agriculture's Natural Resources
Conservation Service worked with local landown-
ers to implement multiple agricultural BMPs in the
lower and upper Joe's Bayou watersheds, including
conservation crop rotation, irrigation land leveling,
nutrient management, cover crops, residue and till-
age management, and structures for water control.
The BMPs were implemented on approximately
4,000 acres of the watershed. Two watershed moni-
toring projects were also funded as part of this plan
through CWA section 319 funds with the University
of Louisiana at Monroe as the Principal Investigator:
"Watershed Monitoring in the Ouachita River Basin
- Upper Joe's Bayou" and "Watershed Monitoring in
the Ouachita River Basin - Lower Joe's Bayou." Both
projects included collecting water quality monitor-
ing data to identify additional priority areas in the
watershed for BMP implementation. In Upper Joe's
Bayou, 29 water quality sampling events occurred
atfive sites from March 2010 and August 2011. In
Lower Joe's Bayou, 25 sampling events occurred at
five sites from January 2012 to June 2013.
As a result of the BMP implementation work
implemented since 2006, average 2013/2014
nitrate-nitrite and phosphorous concentrations
have decreased by 55 and 43 percent, respectively,
compared to the 1999 period (Figure 2).
In addition, average turbidity levels declined
73 percent from 339.4 Nephelometric Turbidity
Units (NTU) for samples collected in 1999, down to
92.3 NTU for samples collected in 2013 and 2014.
LDEQ is hopeful that, with continuing implementa-
tion, dissolved oxygen levels will meet the water
quality standard, and turbidity will continue to
decrease.
Partners and Funding
LDEQ provided approximately $50,000 in CWA
section 319 funds to develop the watershed imple-
mentation plan for Joe's Bayou. LDEQ also pro-
vided $139,041 in CWA section 319 funds with the
University of Louisiana at Monroe providing $63,328
of in-kind match, for a total of $202,369 for the two
watershed monitoring projects in the Ouachita
River Basin. Lastly, LDAF provided $251,432 in CWA
section 319 funds from 2002 through 2008, along
with landowner in-kind match of $479,340, for a
total of $730,772.
Decreasing Nutrients in Joe's Bayou
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Dates
• Nitrate+ Nitrite (as n) — Linear (Nitrate+Nitrite (as n)) • Phosphrous (as p) — Linear (Phosphrous (as p))
Figure 2. Data collected from LDEQ station 0797 show that nutrient levels in
Joe's Bayou decreased between 1999 and 2013.
UJ
(9
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001LL
September 2015
For additional information contact:
Michael Schooler
Louisiana Department of Ag and Forestry
318-435-6743 Ext 122 • mschooler@ldaf.state.la.us
Karen Vidrine
Louisiana Department of Environmental Quality
225-219-1208 • karen.vidrine@la.gov
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