Interdisciplinary WorkshopCase Study

Valley Creek Watershed near Philadelphia, PA

Claire WeltyUMBC (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 ControlSpace 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 anurbanizing 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

Baltimore

Field Site

Valley Creek Watershed - Land-Use History

1650-1700 Colonial Settlement

1700-1850 Agricultural Development

1850-1950 Industrial Development

1950-present Suburban Sprawl

Valley Creek

Little Valley Creek

Valley Forge National Historical Park

Schuylkill River

1 mi 24 mi2

Paoli Rail Yard

• •

••

••

•

Bishop Tube Co.Foote Mineral Co.

Cedar Hollow QuarryCatanach Quarry

Malvern TCE

Knickerbocker Landfill• N.I.K.E. Site

1850-1950 Industrial Development

VFNH Park •

2002 Land Use

17% Impervious Area

Geology

South Valley Hills(Noncarbonate rock)

Chester Valley

(Carbonate rock)

North Valley Hills(Noncarbonate rock)

Fault

Groundwater Flow Paths

Sloto (1990)

•

Bromide Concentrations in Valley Creek

Foote Mineral Site

•

USGS Gauge

Q (

cfs)

Quarry Trib

Hyporheic Zone

Church Rd, 0.0 m

Quarry Discharge, + 320 m

VCP, + 2275 m

Mill Rd, +5510 m

USGS, +7470 m

N

Station Locations for Tracer Test

Valley Creek Natural TracerAt Valley Creek Preserve

0.20

0.30

0.40

0.50

0.60

12:00 14:00 16:00 18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00

Time of Day

Br, mg/L

08/07/01 08/08/01

Quarry Tributary

Bromide Source

VCP

Mill Rd

USGS

•

Valley Creek Natural TracerAt Mill Rd

0.20

0.30

0.40

0.50

0.60

12:00 14:00 16:00 18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00

Time of Day

Br, mg/L

08/07/0108/08/01

Quarry Tributary

Bromide Source

VCPMill Rd

USGS

•

Valley Creek Natural Tracer At Gauge Station

0.2

0.3

0.4

0.5

0.6

12:00 14:00 16:00 18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00

Time of Day

Br, mg/L

08/07/0108/08/01

Quarry Tributary

Bromide Source

VCPMill Rd

USGS•

Best Fit of USGS OTIS Model to Data to Determine Stream Parameters

dCdt

=−QA

dCdx

⎛ ⎝

⎞ ⎠ +

1A

⎛ ⎝

⎞ ⎠

ddx

ADdCdx

⎛ ⎝

⎞ ⎠ +

qlA

Cl −C( )+α Cs−C( )

dCsdt

=αAAs

⎛

⎝ ⎜ ⎞

⎠ ⎟ C −Cs( )

D = longitudinal dispersion coefficient

= hyporheic exchange rate

A = main channel cross-sectional areaAs = storage cross-sectional areaAs /A = transient storage area

http://co.water.usgs.gov/otis/

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

Results

• 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.

••

••

••

•••

•••

••

•

7

1

2

3

45

6

8910

11 12

14

13

15

Creek Chub 15N signal

Food Web Analysis Using Stable Isotopes

Septic System

Steffy and Kilham, Ecological Applications, 14(3), 637-641, June 2004.

Creek Chub 15N signal

Fish DiversityFish Diversity

123

48

910

1411

13

5

615

7

12

2.6 1.8 2.52.95.44.04.0

2.5

3.9

4.4

3.63.2

1.2

Simpson Diversity Index

Totals (taken each section as a whole)

Watershed: 6.3

Main branch: 3.7

VC: 5.6

LVC: 5.0

S = total number of speciespi = proportion of S made up of ith species

€

D =1

pi2

i=1

S

∑

?

Steffy and Kilham, Urban Ecosystems In review

15

7

5

Springs in Valley Creek Watershed

• 108 sampleable springs• Flow rates and major ions measured

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 ChickiesQuartzite

LedgerDolomite

Elbrook Limestone

Conestoga Limestone

Octoraro Phyllite

Water Quality Variograms Related to Geology

pH Calcium

5.0 - 8.3 0.1 - 190 mg/L

Land-Use Indicator Variograms

Public Lands

Farms

Residential Industrial Commercial

Water Quality Variograms Related to Land Use

ChlorideSodium

3 - 180 mg/L 2.6 - 270 mg/L

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

Mathematical Model

Rainfall

GeologyLand Slopes

InputsDetention Basin Surveys

Soils

PercentageImpervious Area

Time

Str

eam

flo

w r

ate

Output

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

2.0 inch rainfall

Peak without basins: 117cfs

Peak with basins: 114 cfs

•  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