Interdisciplinary Workshop
Case Study
Valley Creek Watershed near Philadelphia, PA
Claire Welty
UMBC (University of Maryland Baltimore County)
Center for Urban Environmental Research and Education
& Dept. of Civil and Environmental Engineering
July 19, 2005
Appetite for Land Defies Control
Space is being devoured faster than it's being saved. Where big
homes go, traffic and pollution follow.
First of five parts.
By Diane Mastrull and Nancy Petersen
INQUIRER STAFF WRITERS
Sunday, February 7, 1999
It is development clocked locally at an acre an hour. Twenty-four hours a day, 365
days a year. That is a conservative estimate of how fast the remaining open land
in Philadelphia, Bucks, Montgomery, Delaware, Chester, Gloucester, Camden and
Burlington Counties is being bulldozed.
Goal of Project
• To quantify impacts of development on water
resources and aquatic ecosystems in an
urbanizing watershed
Goals of Presentation
• To illustrate why multidisciplinary approaches can
be helpful for evaluating these kinds of problems
• To demonstrate several types of models utilized in
the project
Field Site
Baltimore
Valley Creek Watershed - Land-Use History
1650-1700 Colonial Settlement
1700-1850 Agricultural Development
1850-1950 Industrial Development
1950-present Suburban Sprawl
Schuylkill
River
Valley Forge National
Historical Park
Valley Creek
Little Valley Creek
1 mi
24 mi2
1850-1950 Industrial Development
VFNH Park
Malvern TCE
•
•
Foote Mineral Co.
Cedar Hollow Quarry
•
•
•
•
Catanach Quarry
•
•
N.I.K.E. Site
Knickerbocker Landfill
Bishop Tube Co.
•
Paoli Rail Yard
2002 Land Use
17% Impervious Area
Geology
North Valley Hills
(Noncarbonate rock)
South Valley Hills
(Noncarbonate rock)
Fault
Groundwater Flow Paths
Sloto (1990)
Bromide Concentrations
in Valley Creek
•
Foote Mineral Site
Valley Creek Flow at USGS Gauge
USGS Gauge
1
Quarry Trib
•
0.9
0.8
Q, cms
Q (cfs)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
8/6/01 12:00 AM
8/6/01 12:00 PM
8/7/01 12:00 AM
8/7/01 12:00 PM
Time
8/8/01 12:00 AM
8/8/01 12:00 PM
8/9/01 12:00 AM
Hyporheic Zone
Station Locations for Tracer Test
N
USGS, +7470 m
Quarry Discharge, + 320 m
VCP, + 2275 m
Church Rd,
0.0 m
Mill Rd,
+5510 m
Quarry Tributary
Valley Creek Natural Tracer
At Valley Creek Preserve
•
USGS
VCP
Mill Rd
Bromide Source
0.60
0.50
Br, mg/L 0.40
0.30
0.20
12:00
14:00
08/07/01
16:00
18:00
20:00
22:00
0:00
2:00
08/08/01
Time of Day
4:00
6:00
8:00
10:00
12:00
14:00
Quarry Tributary
Valley Creek Natural Tracer
At Mill Rd
VCP
•
USGS
Mill Rd
Bromide Source
0.60
0.50
Br, m g/L 0.40
0.30
0.20
12:00
08/07/01
14:00
16:00
18:00
20:00
22:00
0:00
08/08/01
Tim e of Day
2:00
4:00
6:00
8:00
10:00
12:00
14:00
Valley Creek Natural Tracer
At Gauge Station
•
USGS
Quarry Tributary
VC P
Mill Rd
Bromide Source
0.6
0.5
Br , m g/L0.4
0.3
0.2
12:00
08/07/01
14:00
16:00
18:00
20:00
22:00
0:00
2:00
08/08/01
Tim e of Day
4:00
6:00
8:00
10:00
12:00
14:00
Best Fit of USGS OTIS Model to Data
to Determine Stream Parameters
dC Q dC   1  d ADdC  q l



C

C


C

C
l
s
dt
A  dx  A  dx  dx  A

 

 A 
dCs
  C  Cs 
dt
As 
D = longitudinal dispersion coefficient
 = hyporheic exchange rate
A = main channel cross-sectional area
As = storage cross-sectional area
As /A = transient storage area
http://co.water.usgs.gov/otis/
Results
REACH
Quarry to VCP
VCP to Mill Rd
Mill Rd to USGS
Length, km
1.85
3.24
1.96
D, m2/s
1.4
0.5
0.7
As/A
0.07
1.3
0.03
, s-1
2.7E-04
1.0E-02
8.7E-06
• Dispersion, exchange, storage area are flow dependent
• Transient storage zone (As/A) and exchange rate () are
dominant in the middle reach
• Exchange rates () are consistent with type of bed material as
reported in the literature
Ryan, Packman, and Welty, WRR, 40, W01602, doi:10.1029/2003WR002458,January 2004.
Food Web Analysis Using Stable Isotopes
•1
•2
•3
4
9
8
•
5
•
•
•
10
15
14
•• 7• • • 6
11
• 12•
13
•
Creek Chub d15N signal
Septic System
Creek Chub d15N signal
Steffy and Kilham, Ecological Applications, 14(3), 637-641, June 2004.
Fish Diversity
Simpson Diversity Index
13
11
14
10
2.5
Totals (taken each section as a
9
4
4.0 4.0
5.4 2.9
3.9
4.4
7
Watershed: 6.3
2.6
5
2
1.8
1
2.5
6
3.6
1.2
12
Main branch: 3.7
LVC: 5.0
3
15
3.2
whole)
VC: 5.6
8
D
1
S
2
p
 i
i1
S = total number of species
pi = proportion of S made up of ith species
Diversity vs. Impervious Area
Valley Creek
6
below confluence
Little Valley Creek
8
Diversity
5
15
10
4
6
9
3
4
1
5
?
7
3
11
2
2
12
1
0
0
Steffy and Kilham,
Urban Ecosystems
In review
10
20
% Impervious
30
40
Springs in Valley Creek Watershed
• 108 sampleable springs
• Flow rates and major ions measured
15
7
5
Cross-Covariance Between Spring Flow
and Fish Species Diversity
Steffy, McGinty, Welty, and Kilham, JAWRA, 40(5), 1269 - 1275, October 2004
Geostatistical Analysis of
Spring Water Quality
• Geologic vs. Land-Use Signatures
Geology Indicator Variograms
Chickies
Quartzite
Ledger
Dolomite
Octoraro
Phyllite
Conestoga
Limestone
Elbrook
Limestone
Water Quality Variograms Related to Geology
5.0 - 8.3
pH
0.1 - 190 mg/L
Calcium
Land-Use Indicator Variograms
Public Lands
Farms
Industrial
Commercial
Residential
Water Quality Variograms Related to Land Use
3 - 180 mg/L
Sodium
2.6 - 270 mg/L
Chloride
McGinty, A.L..L., MS Thesis, Drexel University, Dept. of Civil, Arch., and Env. Eng., 2003;
McGinty and Welty, in preparation, to be submitted to Hydrogeology Journal, 2005.
Stormwater Management
• 111 detention basins
• Functioning as designed?
• Additive effects?
Assessment Approach:
Stormwater Modeling
Inputs
Rainfall
Detention Basin
Surveys
Percentage
Impervious Area
Soils
Land Slopes
Mathematical Model
Stream flow rate
Geology
Output
Time
Methods
•
•
•
•
•
111 detention basins surveyed, including outflow devices
6 recording raingauges installed in watershed
US Army Corps of Engineers HEC-HMS model chosen
Soils, infiltration, basin, rainfall data incorporated into model
Predictions of storm runoff with and without basins quantified
0
2.0 inch rainfall
Peak without basins: 117cfs
Peak with basins: 114 cfs
Without Detention Basins
With Detention Basins
120
0.1
80
0.15
40
0.2
0
9/20/01 05:00
0.25
9/20/01 21:40
9/21/01 14:20
Precipitation (in)
Flow Rate (cfs)
0.05
• Basins are designed for 2 - 100 yr
storms
• Basins have no effect on small
storms (here ≤ 1 yr)
• 97% of our rainfall falls as small
storms
• Need for revising design criteria
Emerson, Welty, and Traver, ASCE J Hydrologic Eng, 10(3), 237-242, May 2005.
Summary
• Watershed-scale research
> importance of recognizing spatial and temporal
heterogeneity
> natural vs anthropogenic characteristics
• Utilization of existing conditions and data for
process-based, quantitative assessments where
possible