How does the Decomp(artmentalzation) Physical Model help move Everglades Restoration Forward?

Colin SaundersSouth Florida Water Management DistrictNational Conference on Ecosystem RestorationCoral Springs, FL. April, 2016

C. CoronadoS. NewmanF. SklarE. Tate-Boldt

J. HarveyJ. ChoiB. RosenJ. Lewis

D. HoD. Hickman

L. Larsen

Co-authors

C. ZweigE. ClineC. HansenF. Santarmaria

P. RegierR. Jaffe

D. He

F. SklarC. SaundersS. NewmanC. CoronadoC. ZweigS. Hagerthey

J. HarveyB. RosenM. DickmanJ. ChoiJ. Lewis

S. BaisdenS. WilcoxN. GarrattD. CrawfordT. KinseyD. George

J. TrexlerM. Bush

S. BornhoeftM. Ross

P. Ruiz

D. HoD. Hickman

L. LarsenD. Watts

DPM Science Team

A. SwartzJ. GomezK. SkalakL. Soderqvist

E. Tate-BoldtM. MannaE. ClineC. HansenM. BlahaF. Santarmaria

R. JaffeD. He

P. RegierB. JaraJ. Sah

back to this?*

Is it possible to go from

this…

The RestorationChallenge

*McVoy et al.2005

DPM study

DPM study

Impacted ridge & slough landscape

Pre-drainage ridge & slough landscape

Flow …A Critical Piece of the Restoration Puzzle

As you cross from Ridge to Slough the difference is:

Healthy = 20-30 cmImpacted = 0-10 cm

The Bedrock Surface is not reflected on the peat

surface

N

Impacted ridge & slough landscape

Pre-drainage ridge & slough landscape

S

Simulated Landscapes

With flow Without flow

Larsen et al., 2011. Recent and Historic Drivers of Landscape Change in the Everglades Ridge, Slough, and Tree Island Mosaic Critical Reviews in Environmental Science and Technology, 41: 6, 344 — 381

Flow …A Critical Piece of the Restoration Puzzle

The DECOMP Physical Model (DPM)

A landscape-scale field experiment to address scientific, hydrologic, and water management uncertainties for DECOMP

1. Ecological benefits of sheetflow

2. Ecological benefits of removing levees and backfilling canals

Sheetflow Hypothesis Cluster

sloughridge

Do deep water sloughs exhibit higher velocities, more sediment transport?

To what extent does high-flow redistribute sediment (slough to ridge)?

Canal Backfill Hypothesis Cluster

marsh sediment

canal sediment(High Phosphorus)

Does backfilling help maintain natural sediment transport? Does backfilling reduce mobilization of canal sediments? Does backfilling impact fish populations?

DPMFlow-way

Complete Fill

Partial Fill

No Fill

Experimental DesignL67-AS-152

CB1

CB2

CB3

CC2

CC1

RS1

RS2 S1

UB3

UB1

UB2

DB3

DB2

DB1

WCA3A

WCA3B

BACI TIME LINE

month2014201320122011 20162015

JFMAMJJASONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASONDSONDJFMAMJJASOND

AFTER IMPACT MONITORINGBEFORE IMPACT MONITORING

What is Being Measured? Hydrology Hydraulics of L-67A culverts (head and tail water stages and cfs) Tracer studies (SF6 tracer and dye) A network of sites for stage, water depths, flow direction, and velocity Synoptic mapping of water depth and velocity in conjunction with

flow manipulations Vegetation mapping for hydraulic resistance Canal hydraulics

Sediment and Nutrient Dyamics Synoptic mapping of surface water biogeochemistry and sediment

erosive properties Resuspension and deposition of natural particles (LISST) Particle transport (Floc tracers, sediment traps, biogeochemical

markers)

Biological Environmental monitoring (dissolved oxygen, pH, temperature,

specific conductivity) Fauna characterization (native and exotic) and movement Vegetation and periphyton structure

Flow field resolved with water tracers

180 min

5 min post-injection

N

10 min

Dye tracer, 2013

5 cm s-1

Dye (E. Cline)SF6 (D. Ho)

S-152

0.4 cm/s

0.3 cm/s

1 cm/s2 cm/s

5 cm/s

1 cm/s

The Initial Pulse - Tracking Sediment and Phosphorus Across the Landscape

N

S. Newman, E. Tate-Boldt, C. Hansen, Christa Zweig (SFWMD)

Data from Harvey, Choi, Dickman (USGS)

Flow velocities increased with flow duration and despite

steady discharge

RS1 Slough Velocity

S152 discharge

RS1 stage

Data from C. Saunders, SFWMD

C1

0.000

0.004

0.008

0.012

0.016 ridgeslough

RS1

mas

s lo

adin

g pe

r fro

ntal

are

a (g

cm

-2 d

-1)

0.000

0.004

0.008

0.012

0.016

RS2

Date6/11 10/11 2/12 6/12 10/12 2/13 6/13 10/13 2/14 6/14 10/14 2/15 6/15

0.000

0.004

0.008

0.012

0.016

C1

RS1

RS2

ridgeslough

Load

per

fron

tal a

rea

(g c

m-2

d-1)

Date

Sediment transport increased with sustained flow

– Physical properties matched to natural Everglades floc

– recaptured using 11 Guass magnets –synoptic surveys and downstream capture

– UV-fluorescent, different colors to track multiple cohorts

Tracer

Tracking Floc Movement –Synthetic Tracer

E. Tate-Boldt - NCER poster

S152

Slough Tracer Drop

Tracking Floc Movement

see E. Tate-Boldt et al. NCER poster

Slough

-6 -3 0 3 6meters

6

3

0

-3

-6

# Particles

Ridge-Edge

Slough-6 -3 0 3 6

meters

6

3

0

-3

-6

Ridge-Edge Drop

Video by C. Saunders - SFWMD

Distance East (m)0 5 10 15 20

Floc

Hei

ght (

cm)

0

5

10

15

20

25

30

35

2 weeks6 weeks10 weeks

RS1 – SloughFloc Height Transect

Slough Floc Reduced Under Sustained Flow

Data from C. Saunders, E. Tate-Boldt, C. Hansen, S. Newman - SFWMD

Distance East (m)0 5 10 15 20

Floc

Hei

ght (

cm)

0

5

10

15

20

25

30

35

2 weeks6 weeks10 weeks

Slough Floc Reduced Under Sustained Flow

5

10

15

20

5

10

15

20

Floc

Hei

ght (

cm)

5

10

15

20

Weeks After Flow Starts-10 0 10 20

5

10

15

20

Pre-Flow

Flow #1

Flow #2

Flow #3

RS1 – SloughFloc Height Transect

Data from C. Saunders, E. Tate-Boldt, C. Hansen, S. Newman - SFWMD

Measuring Floc Erodibility - Benthic Annular Flume

Photos from PARTRAC 2008. (Glasgow, UK)

Floc More Erodible After Sustained High Flow

Z5-1

Time (s)0 1000 2000 3000 4000 5000

Turb

idity

(NTU

)

0

20

40

60

80

100

120

Velo

city

(cm

/s)

0

1

2

3

4

5

6Feb 2015Oct 2014 Flume speed

CriticalErosionThresholdVelocity

Erosion“Capacity”

Data from S. Newman and M. Manna (SFWMD)

Floc More Erodible After Sustained Flow

Z5-1

Time (s)0 1000 2000 3000 4000 5000

0

20

40

60

80

100

120

Velo

city

(cm

/s)

0

1

2

3

4

5

6Feb 2015Oct 2014 Flume speed

150-m (high)RS1

Time (s)0 1000 2000 3000 4000 5000

0

20

40

60

80

100

120

0

1

2

3

4

5

6Feb 2015Oct 2014Flume speed

350-m (high) 1000-m (Control)

Data from S. Newman and M. Manna (SFWMD) - 2016 SFER

Changes in Algal Taxa of Advected Sediments

Pinnularia(diatom)

Botryococcus(green alga)

Data from B. Rosen (USGS)

RS1Ridge RS1 Slough

# al

gal s

peci

es /

sam

ple

Biochemical Composition of Floc Changes with Flow

Data from R. Jaffe, P. Regier, D. He (FIU) - 2016 SFER

Bot

ryoc

occ.

Con

cent

ratio

n (u

g/ g

) 150-m

350-m

700-m

1000-m

1000-m

2000-m

Green Algae

Botryococcanes

Flow#1 Flow#2

Restoration and Management Implications – Findings from the Ridge-and-Slough

Sustained high flows of 8+ weeks effectively “clear sloughs” by self-reinforcing feedbacks higher velocities, increased transport, reduction in floc Short-duration pulse flows increase suspended sediments 10-fold but limited spatial impact. High flows triggered mechanisms that rebuild topography –slough velocities sufficient to entrain and redistribute sediments from sloughs into ridges Restoration Milestones - After successive flow events, floc chemistry changes are observed farther downstream. Monitoring “fast responding” parameters could set expectations about how landscapes respond to restored flow

Sheetflow Restoration -The Big Picture

S152

S152 flows move radially and preferentially eastward, diluting sheetflow and sediment transport Some water was expected to mound up along the L67C levee, redirecting flow south

Sheetflow Restoration -The Big Picture

S152

That water is re-routed by the canal toward the gap, maintaining radial flow … and mobilizing canal sediments “Getting the flow direction right” requires 2 fixes Importance of doing adaptive management experiments in the restoration footprint

Physical & Biogeochemical-mediated responses in sloughs

Flow

SAV breaks up& clears out

Floc reduced

Increasedgreen algaederived OM

Floc more erodible, decays faster,

higher TP

Sediments transported down-slough, and/or settle in ridges

Flow downstream

SAV breaks up& clears out

Floc reduced

increasedgreen algaederived OM

Floc more labile, decays faster, more erodible

Sheetflow Restoration -The Big Picture

S152

S152 flows move radially and preferentially eastward, diluting sheetflow and sediment transport Some water was expected to mound up along the L67C levee, redirecting flow south

*** REALITY ***

That water is re-routed by the canal toward the gap, maintaining radial flow … and mobilizing canal sediments “Getting the flow direction right” requires 2 fixes - active adaptive management (opening up remnant sloughs) and measures to slow canal flows Importance of doing adaptive management experiments in the restoration footprint itself