Nutrient and Bacterial Fluxes in Urban Watersheds of the Gwynns Falls, Baltimore, MD. 

Belt, K. T.1, P. M. Groffman2, L. Band3, N. Law3, and G. T. Fisher4.

1 US Forest Service/Baltimore Ecosystem Study, 2 Institute of Ecosystem Studies, 3 University of North Carolina, 4 US Geological Survey 

Baltimore LTER

Urban Land Use Change

Stream Temperatures…Base & Stormflow

Maximum Daily Stream Temperatures Pond Branch & Glyndon Summer 1999

16

18

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28

30

9-Jul 14-Jul 19-Jul 24-Jul 29-Jul 3-Aug 8-Aug 13-Aug 18-Aug 23-Aug

Te

mp

era

ture

(C

)

GLYNDON (Suburban)

POND BRANCH (Forested)

Suburban vs. Forested Watersheds

The Urban Hydrograph

Urban vs Forested Storm Hydrographs

0

50

100

150

200

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300

350

400

0 2 4 6 8 10 12 14 16

Time

Flo

w R

ate

UrbanUrban

Forested

Storm Drain Storm Drain Outfall & GageOutfall & Gage

36”36”

18”18”

18”18”

36”36”

42”42”

StreamStream

Storm Drain ConduitsStorm Drain Conduits

Drainage BoundaryDrainage BoundaryStorm Drain ConduitStorm Drain ConduitManhole AccessManhole AccessInlet & CatchbasinInlet & Catchbasin

Channel Incision

II. Channel with Incision Due to Increased Runoff

Water Table Stream

•Channel Erosion•Nonfunctional Floodplain•Dry Riparian Soils

I. Natural Channel with Connected Riparian Zone

Gravity Sewers… Interwoven with Fluvial Systems

Main LineInterceptor

FeederLines

Sewer Leakage Paths to Streams

h Feeder Line

Main SewerInterceptor Pipeline

Stream

Water Supply

Wastewater

Stormdrains

Groundwater

Septic Systems

Impervious Surface

Artificial Channels

Stream

Civil infrastructure becomes part of the stream system

The Urban Hydrologic System

Rognel Hts Storm Sewer

Carroll Park Main Channel

McDonogh Weir

Monthly Average Flows (cm/yr)Gwynns Falls & Dead Run Water Year 1999

10

100

10 11 12 1 2 3 4 5 6 7 8 9

Month

Flo

w (

cm

/yr)

Carroll Pk

Villa Nova

Gwynnbrook

Dead Run MID

DOWN

UP

DEAD RUN

?

Urban Watersheds with More Baseflow?

0

2

4

6

8

10

12

14

16

Pond Bra

nch

Baism

ans R

un

Glyndon

Red Run

1

Red Run

2

Horse

Head B

ranch

Scotts

Leve

l 1

Scotts

Leve

l 2

Dead R

un

GF at G

wynnbro

ok

GF at O

wings

Mills

GF at V

illa N

ova

GF at C

arroll P

ark

Nit

rate

(m

g/l) 1

2

3

Nitrate In the Urban-Rural Gradient

Urban…Greater Annual Runoff

WY 1999 Runoff (cm)

WY 2000 Runoff (cm)

0

10

20

30

40

50

60

70

An

nu

al R

un

off

(c

m)

Annual Stream RunoffWater Years 1999 & 2000

WY 1999 Runoff (cm)

WY 2000 Runoff (cm)

Annual Nitrate Yields

WY 1999

WY 2000

0

2

4

6

8

10

12

14

16

Nitrate N Annual Yield (Kg/ha)

Annual Nitrate YieldsWater Years 1999 & 2000

WY 1999

WY 2000

Annual Phosphate Yields

WY 1999

WY 2000

0

20

40

60

80

100

120

140

160

180

200

Phosphate P Annual Yield (g/ha)

Annual Phosphate YieldsWater Years 1999 & 2000

WY 1999

WY 2000

A Little Leakage…Goes a Long Way

Nitrate N

0

1

2

3

4

5

Annual Nitrate N Yield (Kg/ha)

5% Sewage Leak & Measured Stream Nitrate Yields Glyndon (81 ha)

5 % Sewage Leak

Stream Load WY00

Phosphate P

0.00

0.05

0.10

0.15

0.20

0.25

Annual Phoshphate P Yield (Kg/ha)

5% Sewage Leak & Measured Stream Phosphate Yields Glyndon (81 ha)

5 % Sewage Leak

Stream Load WY00

0%

20%

40%

60%

80%

100%

Dr.Area Cl NO3 TN TP PO4 SO4 FC

% Contribution from Gwynns Run Tributaryto the Gwynns Falls

Restoration Objectives…Multiple Choices

Pathogens in Urban Watersheds

Fecal Coliforms are used as indicators of sewage contamination…but

14-J

un-0

1

2-Ju

l-01

23-J

ul-0

1

20-A

ug-0

1

10-S

ep-0

1

2-O

ct-0

1

5-N

ov-0

1

26-N

ov-0

1

17-D

ec-0

1

16-J

an-0

2

4-F

eb-0

2

26-F

eb-0

2

18-M

ar-0

2

8-A

pr-0

2

29-A

pr-0

2 GFGBGFVN

GFCPGFGR

10

100

1,000

10,000

100,000

1,000,000

Fecal Coliform (org/100 ml)

GFalls Main Channel & Gwynns Run Tributary

GFGB

GFVN

GFCP

GFGR

Disproportionate Impacts…Public Health Issues ?

?

Monitoring Station

Input: Fertilizer,

21.5

8.5

23.5

Output: Measured Loads in the Stream

6.5 Kg/ha/yr

Glyndon: 80 % of Nitrogen is Missing…Where did it go?

Input: Atmospheric Deposition

Researchers

Lawrence BandKen BeltMark ColosimoPeter GroffmanNeely LawGary Fisher

Students/Techs

Alex KalejsJessica HopkinsNate Forand Evan GrantAlan Lorefice Steve KenworthyAlysia PerryEmilie StanderAmanda ThimmayyaIan Yesilonis

Institutions

IESForest ServiceJohns HopkinsUNCNRCSUSGS