Materials Transport & NSCD

Material ClassesVelocity to Transport Relationships

York NSCD RestorationPSY CCREP

Material Transport

• Organic Matter: DOM (70-90%), FPOM, CPOM, large woody debris (branches to whole trees).

• Inorganic Matter (Mineral): alluvium & bedload• Higher discharge streams can carry more and

larger particles.– Suspended load: fine suspended particles (turbidity).– Bed load: Larger particles that bounce along bottom of

stream.– The relative amount of suspended vs. bed loads is

dependent on velocity and turbulence of stream flow.

After rain, higher turbidity is not just a function of sediment run off; higher flow velocity suspends more sediments from bottom.

Total concentration of suspended particles highest near bottom.

Velocity & Material Transport Size

Deposition vs Erosion

Sediment Impacts & Contamination• Excess Sedimentation:

– Reduces hard substrate for periphyton.– Clogs gravel interstices; reduces spawning habitat for fish.– Microbial activity increase may cause oxygen depletion.– Filling and flooding.– Increases drinking water treatment costs; reduces aesthetics.

• Many chemicals, contaminants will collect within and adhere to sediments.

• Variable transport of contaminated sediments can have severe impact on biota:– Sediments collect in pools– Contaminated sediments can be retained for long periods of

time.• Erosion is more aggressive due to unstable stream

banks, flashy storm response, or sediment starved waters (e.g. below dams)

Rates of Stream-Bank Erosion

Cross Section of SBCC

486

488

490

492

494

496

498

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200

Distance (ft)

Ele

vatio

n (ft

)

Aquatic Resource Restoration Company (ARRC), unpublished data

June 2003

March 2004

October 2004

About 2-20 ft of bank lost per year.

This is 10-100 times faster than expected.

How can we stabilize our stream channels?

Continuous monitoring instrumentation (below) is placed in the stream for a

month at a time

23 September 2003

Hour (from 17:00 on 09/22/2003)

17 21 01 05 09 13 17

Dis

char

ge (m

3 /h)

Sus

pend

ed S

edim

ent L

oad

(kg/

h)

0

2e+4

4e+4

6e+4

8e+4

1e+5

Rai

nfal

l (in

ches

per

hou

r)

0.0

0.1

0.2

0.3

0.4

DischargeSS LoadRainfall

Data collected during a storm event (above) illustrates that this is when most erosion occurs.

NSCD• Natural Stream Channel Design

• Based on science of water flow = hydrology

• New channels may be created with meanders.

• Man-made structure of rock or logs to divert flow and slow erosion.

• Considers watershed size, climate, topography and geology to determine the proper dimensions, pattern and profile for no net erosion or accretion.

“J”-hook structures along meanders.

Natural Stream Channel Design (NSCD)

Replacing the streamside (riparian) forest.

odorus Creek Restoration Efficacy Program Studying the Effectiveness of NSCD Restoration Efforts

- Does water quality during storm events improve?

- Is there a positive biological community response?

(periphyton, macroinvertebrates, finfish)

South and East Branch

Watersheds

Downstream Continuous Monitoring Sites

Upstream Reference Sites

Completed Restoration

Planned Restoration

Water Quality& Flow

• We measure nutrients and suspended sediments in water samples during all conditions and all year!

• We also measure the stream flow to determine how much nutrient and sediments travels downstream.

Storm Event Volume to Sediment Load(3/2003 – 3/2004)

Storm Event Volume (1000 x m3)

1 10 100 1000Sed

imen

t Loa

d (m

etric

tons

)

0.1

1

10

100

1000

?

Periphyton = “rock slime”Indicator of nutrient and sediment pollution.

We also monitor the macroinvertebrate community, which mostly includes stream

insects.

Fish surveys by electrofishingPeter Siwik

PA Council of Trout Unlimited, 2002

Wild spawning trout would be a hallmark of restoration success, but it will likely require fisheries management changes such “catch and release”.

Below Sewage Treatment

Plants!

Parasites

Infections

Deformations