[PDF] - Ramanessin Brook Project Overview Evaluate sources of fecal PDF Document

SLIDE 1

1

RAMANESSIN BROOK STORMWATER MODELING & POLLUTANT LOADING STUDY

Monmouth County Planning Board Navesink-Swimming River Group 319(h) Grant funded through NJDEP

October 26, 2005 Presented by: Jeremiah D. Bergstrom, CLA, ASLA Thomas Amidon, MS Gopi Jaligama, MS

Ramanessin Brook Project Overview

Evaluate sources of fecal

coliform and phosphorus

Develop a hydrologic

model and watershed pollutant-loading model

f the stream

Assess water quality

impacts due to nonpoint sources

– erosion – stormwater

SLIDE 2

2

Primary Tasks

Watershed characterization and assessment Water quality sampling program

– fecal coliform (FC) – total phosphorus (TP) – total suspended solids (TSS)

Develop a GIS-based pollutant loading model Collect necessary data and develop a

hydrologic and hydraulic model

Analyze watershed and present findings

Overview of Presentation

Watershed Characterization Field Sampling Watershed Analyses

– Glauconitic Soils Evaluation – Hydrologic and Hydraulic Modeling and Analyses – Shear Stress Analysis – Pollutant Loading Modeling and Analyses

Water Quality Results

– Bacterial indicators – Phosphorus – Suspended solids

Implications and Recommendations

SLIDE 3

3

Watershed Characterization

Total Area = 6.3 square miles (4,040 acres) Ramanessin Brook flows approximately 5 miles

falling nearly 300 feet from its headwaters to its mouth at the Swimming River Reservoir

Primary water quality concerns include aquatic

life, fecal coliform, and total phosphorus impairments

Landuse Characterization for Ramanessin Brook Area : 6.315 sq mi. Curve Number: 76

AGRICULTURE 18% BARREN LAND 1% FOREST 18% UrbanCOM 17% UrbanRES 28% WATER 1% WETLANDS 17% AGRICULTURE BARREN LAND FOREST UrbanCOM UrbanRES WATER WETLANDS

SLIDE 4

4

2002 Aerial Photograph Soil Characteristics

Upland soils –

Freehold-Urban Land- Collington Complex

Flood plain soils –

Humaquepts, frequently- flooded-Manahawkin

Soils high in glauconite –

0% to 40% glauconite

Groundwater recharge rates –

above-average throughout the watershed

–

area weighted average of 10.4 inches per year

SLIDE 5

5

Flood Plains, Wetlands and Streams

Extensive flood plain wetland

areas remain

–

nearly 1200 acres

Flood plain –

approximately 250 ft wide

–

it expands to nearly 500 ft in width near its mouth

Wooded wetland areas along

many stream segments

Extensive downcutting of the

stream bed has occurred

–

steep banks throughout much of the stream reach

Diagnosing Sediment Impacts

Properties of glauconitic

soils

– high iron content – binds phosphorus – erodable clay particles – may create a sustainable

habitat for bacteria

Water quality and

sediment samples

– better understand role of

sediments as a source of NPS pollutants in stream

SLIDE 6

6

Field Sampling

Bi-weekly sampling over

a 12 month period

Flow and water quality

under various flow conditions

Pressure transducers

installed to continuously record stream depth

Stream bed sediments

and bank soils analyzed

– Particle size – FC and TP

Sampling Stations

RB1 –

North Branch @ Crawfords Corner

RB2 –

West Branch @ Longstreet Rd

RB3 –

Roberts Rd Bridge

RB4 –

Main St Bridge

RB5 –

Willow Brook Rd Bridge

BASE –

Unnamed tributary

SLIDE 7

7

Sampling Events

Stream survey

– 55 detailed cross-sections

Flow and water quality sampling

– Bi-weekly for one year – Flow, total phosphorus, dissolved reactive

phosphorus, total suspended solids, turbidity, fecal coliform, fecal streptococcus (limited)

– 5 high-flow, 6 low-flow, 13 ambient flow events

Soil sampling (May 3, 2005)

– Chemical, biological, and particle size analyses

Glauconitic Soils Evaluation

Determine potential for erosion of glauconitic

soils within the Ramanessin Brook Watershed

Using the USLE factoring in percent

glauconite, soil erodibility and slope

Identify areas with potential for eroding high

amounts of glauconite into waterways independent of land use activities

SLIDE 8

8

Glauconitic Soils Evaluation Glauconitic Soils & Land Use

SLIDE 9

9

Purpose of Watershed Modeling

Better understand response of stream flows to

precipitation

Provide basis for evaluating flooding potential Better understand erosion potential under

various flows

Better understand potential sources of

pollutants in the stream

Evaluate impact of land use changes

Modeling Approach

Hydrologic Modeling with HEC-HMS Hydraulic Modeling for Steady State

Simulations with HEC-RAS

Hydraulic Modeling for Dynamic Simulations

with DAFLOW / WAMIT

Pollutant Loading Modeling using WAMIT

SLIDE 10

10

H&H Modeling Summary

Estimated volume of surface runoff from

various design storms

– 1, 2, 10, 100 year storms

Completed a 6 month continuous simulation to

analyze real-time flows

– November 3, 2004 through May 4, 2005

Estimated the shear stress in different stream

reaches for various design storms

Estimated total volumes, peak flows, total

loads, and total shear stress for design storms

HEC-HMS Model

Delineated Watersheds and Streams

–

20 Sub-Watersheds

Defined Watershed Parameters

–

Flow path length for estimating Time of Concentration (Tc)

–

Area weighted curve numbers (CN)

CN = 76 (existing conditions)

Defined Critical Storms and Precipitation

–

Design Storms (Shape and intensity)

–

Hourly precipitation data - Holmdel Weather Station (11/3/04-5/4/05)

Defined Flow Routing Parameters

–

Channel slope

–

Manning coefficients

–

Channel length

Calculated runoff using the SCS curve

number method (TR 55)

SLIDE 11

11

Sub Watershed Composite Curve Numbers

0.620 1.435 0.39 1.93 84 83.200 R550W550 0.620 1.628 0.43 2.17 82 134.599 R530W530 0.620 1.714 0.41 2.05 83 141.138 R510W510 0.620 1.399 0.69 3.45 74 78.651 R490W490 0.620 1.161 0.55 2.74 79 80.691 R480W450 0.620 1.342 0.78 3.91 72 101.691 R470W470 0.620 1.425 0.49 2.46 80 154.503 R430W410 0.620 1.376 0.33 1.64 86 99.585 R420W420 0.620 1.724 0.90 4.48 69 404.970 R40W570 0.620 2.412 0.62 3.09 76 632.462 R400W220 0.620 1.753 0.42 2.09 83 174.073 R380W380 0.620 2.407 0.68 3.39 75 474.464 R370W160 0.620 1.486 0.42 2.08 83 153.916 R360W320 0.620 1.878 0.81 4.04 71 280.094 R250W250 0.620 1.211 0.72 3.59 74 108.032 R240W230 0.620 1.596 0.62 3.12 76 137.761 R180W180 0.620 1.203 0.86 4.28 70 76.699 R150W150 0.620 1.202 0.72 3.58 74 62.048 R140W140 0.620 1.974 0.76 3.80 72 584.168 R130W20 0.620 1.261 0.58 2.92 77 79.135 R110W560 Cp Tp Snyder Coefficients Ia (Initial Abstraction) S (Retention) CN Area Wt Area (Acres) Sub Basin

Design Storm Rainfall Totals

8.9 100-Year Storm 5.2 10-Year Storm 3.4 2-Year Storm 2.9 1-Year Storm 24-HR RAINFALL (INCHES) TYPE III STORM

Monmouth County Rainfall Totals for Standard Design Storms

SLIDE 12

12 Precipitation hydrograph from Holmdel weather station = rainfall record gaps

Hydraulic Model: Steady State Simulation using HEC-RAS

Initial Setup with HEC-GeoRAS Cross section information derived from

surveyed cross sections

– over 50 cross sections along the approximately 5

mile stream length including 4 bridges

Performed steady state flow simulations

– Peak flows from HEC-HMS used as input for design

storms

– Can be used to determine flood elevations and

extent

SLIDE 13

13

Sample Cross Section (Upstream of RB3) Sample Cross Section (Upstream of RB3)

SLIDE 14

14

Sample Bridge / Culvert (RB4) Sample Bridge / Culvert (RB4)

SLIDE 15

15

Hydraulic Modeling: Dynamic Flows using DAFLOW / WAMIT

DA-FLOW

– A one-dimensional flow model developed by USGS

Watershed Model Integration Tool (WAMIT)

– a GIS-based interface to link sub-watershed flows

generated by HEC-HMS with DA-FLOW

– Calculates instream velocities and shear stresses

Results used to calculate depths, velocities

and shear stresses at various locations in the stream under various conditions

DAFLOW / WAMIT Interface

SLIDE 16

16

DAFLOW / WAMIT Results H&H Analyses

Peak Flow Calculations for each sub-

watershed under 1, 2, 10, & 100 Year Storm Events

Total Volume Calculations for each sub-

watershed under 1, 2, 10, & 100 Year Storm Events

Total Shear Stress for each stream reach

under 1, 2, 10, & 100 Year Storm Events

SLIDE 17

17 Land Use Scenarios

Existing Conditions

–

1995/97 NJDEP Land Use / Land Cover

Build-out Condition

–

all agricultural areas and 50% of forested areas converted to developed condition (2/3 residential, 1/3 commercial)

–

Assumes historic stormwater management practices

Forested or Undeveloped

Condition

–

all agricultural and urban land use converted to forest cover

84 84 78 R550W550 83 82 71 R530W530 83 83 77 R510W510 74 74 67 R490W490 79 79 72 R480W450 72 72 61 R470W470 80 80 71 R430W410 87 86 79 R420W420 73 69 63 R40W570 78 76 69 R400W220 83 83 74 R380W380 77 75 66 R370W160 84 83 73 R360W320 73 71 65 R250W250 76 74 67 R240W230 78 76 68 R180W180 74 70 66 R150W150 78 74 69 R140W140 74 72 62 R130W20 77 77 64 R110W560 Build Out Condition Existing Condition Pre-Developed Condition

Peak Flow Analyses

2.16% 15.63% 100-year 4.62% 25.44% 10-year 7.86% 36.32% 2-year 9.77% 41.17% 1-year AVERAGE PERCENT INCREASE IN PEAK FLOW EXISTING TO BUILD- OUT CONDITION AVERAGE PERCENT DECREASE IN PEAK FLOW EXISTING TO PRE- DEVELOPED CONDITION DESIGN STORM

SLIDE 18

18

Peak Flow Comparisons Peak Flow Comparisons

SLIDE 19

19

Peak Flow Comparisons Peak Flow Comparisons

SLIDE 20

20

Total Volume Analyses

2.93% 15.46% 100-year 4.80% 23.30% 10-year 7.18% 31.69% 2-year 8.42% 35.50% 1-year AVERAGE PERCENT INCREASE IN VOLUME EXISTING TO BUILD- OUT CONDITION AVERAGE PERCENT DECREASE IN VOLUME EXISTING TO PRE- DEVELOPED CONDITION DESIGN STORM

Volume Comparisons

SLIDE 21

21

Volume Comparisons Volume Comparisons

SLIDE 22

22

Volume Comparisons Summary of Hydrologic Analyses

Changes in land use have dramatically altered

peak flows and volumes

Changes most significant during smaller (more

frequent) storm events

Stormwater management focusing on smaller

storm events in specific sub-watersheds will provide the most significant changes in runoff flow and volume

Retrofits are more important than new

development requirements

SLIDE 23

23

Shear Stress Analysis

Used output from DAFLOW to calculate

average velocity and shear stress at various locations in the Ramanessin Brook

Calculated critical shear stress (point above

which erosion occurs)

– used particle size and specific gravity of the stream

bed sediments

Compared shear stress calculations with

critical shear stress

Shear Stress at RB1

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 10/28/2004 0:00 11/17/2004 0:00 12/7/2004 0:00 12/27/2004 0:00 1/16/2005 0:00 2/5/2005 0:00 2/25/2005 0:00 3/17/2005 0:00 4/6/2005 0:00 4/26/2005 0:00 5/16/2005 0:00 Date-Time Shear Stress (Lb-Force/ft^2) 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 Precipitation (in) Shear Stress (Lb/ft^2) Critical Shear stress(Lb/Ft^2) Precipitation (in)

SLIDE 24

24

Shear Stress at RB5

0.1 0.2 0.3 0.4 0.5 0.6 10/28/2004 0:00 11/17/2004 0:00 12/7/2004 0:00 12/27/2004 0:00 1/16/2005 0:00 2/5/2005 0:00 2/25/2005 0:00 3/17/2005 0:00 4/6/2005 0:00 4/26/2005 0:00 5/16/2005 0:00 Date-Time Shear Stress (Lb-Force/ft^2) 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 Shear Stress (Lb/ft^2) Critical Shear stress(Lb/Ft^2) Precipitation (in)

Precipitation (in)

SLIDE 25

25

Pollutant Loading Model (WAMIT)

Sub-watershed flows obtained from hydrologic

model

Runoff EMCs calculated using stormwater sampling

data from nearby Raritan River Basin and Toms River Basin

Landuse EMCs flow-weighted for each sub-

watershed

WAMIT provides direct linkage between DA-FLOW

and WASP

– sediment transport model would be needed

DAFLOW / WAMIT Interface

SLIDE 26

26

Pollutant Loading Analyses

Estimated total load per day for TP, TSS, and

FC for each sub watershed based on total volumes under 1 & 2 Year Storm Events

Compared estimated loads with measured

loads during sampling events for a six month simulation

SLIDE 27

27

SLIDE 28

28

Total Phosphorus

1 2 3 4 5 6 RB1 RB3 RB4 RB5 Sampling Stations Average Ratio of Observed Loads to Predicted Loads

Total Suspended Solids

1 2 3 4 5 6 RB1 RB3 RB4 RB5 Sampling Stations Average Ratio of Observed Loads to Predicted Loads

SLIDE 29

29

Fecal Coliform

1 2 3 4 5 6 RB1 RB3 RB4 RB5 Sampling Stations Average Ratio of Observed Loads to Predicted Loads

Results: Sediment Quality Analyses

Bank and bed results were nearly identical Results between sites were similar Sediment was consistently high in phosphorus

(144 mg/kg Avg TP)

Sediment was low in fecal coliform

SLIDE 30

30

Results: Water Quality Analyses

Phosphorus

– Total phosphorus vs TSS – Total phosphorus vs Iron – Total phosphorus vs turbidity

Suspended Solids

– TSS vs. flow

Bacterial Indicators

– Fecal coliform vs flow – Fecal coliform vs TSS

Total Phosphorus vs. TSS RB5

0.00 0.10 0.20 0.30 0.40 0.50 0.60 10 20 30 40 50 60 TSS (mg/L) Total Phosphorus (mg/L)

SLIDE 31

31

Total Phosphorus vs. Iron at RB5

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 Iron (mg/L) Total Phosphorus (mg/L)

Total Phosphorus vs. Turbidity at RB5

0.00 0.10 0.20 0.30 0.40 0.50 0.60 10 20 30 40 50 60 70 80 Turbidity (NTU) Total Phosphorus (mg/L)

SLIDE 32

32

Summary: Total Phosphorus

Phosphorus is highly correlated with TSS, iron,

and turbidity

Iron-rich sediments from glauconitic soils bind

phosphorus to particles

– Phosphorus is rendered unavailable for plant and

algal growth in the stream (in presence of oxygen)

Observed levels of phosphorus cannot be

explained by runoff loads, especially downstream

Erosion represents a major phosphorus source

TSS

5 10 15 20 25 30 35 40 45 Base RB1 RB2 RB3 RB4 RB5 TSS (mg/l) Mean 90th Percentile FW2-TM Criterion

SLIDE 33

33

TSS vs. Flow RB4

20 40 60 80 100 120 140 160 180 200 10 20 30 40 50 60 Flow (cfs) TSS (mg/L)

Summary: Total Suspended Solids

Under high flows, TSS exceeds FW2-TM

criterion in downstream areas

Observed levels of TSS cannot be explained

by runoff loads, especially downstream

Erosion represents a major source of TSS

SLIDE 34

34

Fecal Coliform

200 400 600 800 1,000 1,200 Base RB1 RB2 RB3 RB4 RB5 Geometric Mean (Colonies/100ml) Summer Geometric Mean Winter Geomoetric Mean Geomean Std

Fecal Coliform vs. Flow RB4

1 10 100 1000 10000 100000 0.00 10.00 20.00 30.00 40.00 50.00 60.00 Flow (cfs) Fecal Coliform (#/100ml)

SLIDE 35

35

Fecal Coliform vs. TSS RB4

1 10 100 1000 10000 100000 5 10 15 20 25 30 35 40 45 50 TSS (mg/L) Fecal Coliform (#/100ml)

Summary: Fecal Coliform

Summer samples much higher than winter Standards exceeded at reference station in summer High levels of bacterial contamination observed at both

low and high flows

Fecal coliform appears to be correlated with TSS when

TSS is high

Observed fecal coliform levels may be explained based

n runoff and baseflow loads

– Fecal contamination does not appear to be caused by erosion

f bacteria-rich sediments