Westshore Seagrass Transplanting Project€¦ · August 2017 Plot 1 Plot 2 Plot 3 Plot 4 Plot 5...

Westshore Seagrass Transplanting Project City of Tampa, Heather Maggio

Tampa Bay Watch, Serra Herndon

History of Canal Dredging Project

• Most Westshore residential canals were created in the 1950’s

• No maintenance responsibility was established

• Citizen requests to dredge sediment buildup for decades

• City analyzed need for dredging in over 30 residential canals

• City developed a project to perform maintenance dredging

• Surveyed the canal for baseline conditions

Project Dredge Design and Criteria

• 20 foot-wide mechanical dredge down centerline of canals • Dredge canal bottom to -5.0 foot mean low water • Assumed slope from outside edges of dredge; this material will also be

removed from within the 20’ wide centerline cut • No impacts to environmental resources (seagrass, oysters, mangroves) • Setbacks: 5’ from docks 10’ from seawall 5’ from env. resources • Dredge materials disposed of at permitted site in Port Tampa Bay

City’s Construction Contract

• City issued a construction contract to Duncan Seawall for $2.8 Million

• Notice to Proceed issued 2/21/13

• 10 canals received dredging under the contract

• Contract includes dredging of 55,000 cubic yards of material, including contingency amount

Canal 20

Project Total Numbers

• 949 square meters of seagrass transplanted to 14 total plots= 2,300 plugs

• COT mitigation was 1,900 plugs- 9 plots of 20m x 10m and 1 plot of 10m x 10m= 1,900 square meters

• TBEP mini-grant project was 400 additional plugs- 4 plots of 10m x 10m= 400 square meters

Monitoring Methodology

• Monitor semi-annually in 2015, 2016 and annually 2017-2019 • Braun Blanquet cover abundance • Short Shoot Density • Canopy Height • Bioturbation • Presence of attached or drift algae

• Monitoring reports submitted to USACE & FDEP annually

Septe

mber

2015

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Plot

10

Ref

H.w. %

Cover

26-

50%

5-25% 26-50% 26-

50%

26-

50%

26-

50%

26-

50%

5-25% 5-25% 5-25% <5%

S.f. %

Cover

0 0 5-25% 0 0 0 0 0 0 0 0

August

2017

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Plot

10

Ref

H.w. %

Cover

76-

100%

76-

100%

51-75% 76-

100%

76-

100%

76-

100%

76-

100%

51-75% 51-

75%

76-

100%

5-

25%

S.f. %

Cover

0 0 5-25% 0 0 0 0 0 0 0 0

T.t %

Cover

0 0 0 0 0 0 0 <5% 0 0 0

September

2016

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Plot 9

Plot

10

Ref

H.w. % Cover 26-

50%

76-

100%

51-

75%

76-

100%

76-

100%

51-

75%

76-

100%

51-

75%

51-

75%

51-

75%

5-

25%

S.f. % Cover 0 0 0 0 0 0 0 0 0 0 0

T.t % Cover 0 <5% 0 0 0 0 0 <5% 0 0 0

One Year Monitoring 2015

Two Year Monitoring 2016

Three Year Monitoring 2017

August

2017

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Ref

SSD 9.7Hw 10.1Hw 8.2 Hw

6.6Sf

10.7Hw 14.6Hw 8.1Hw 8.8Hw 7.6Hw

2Tt

7.6Hw 11.7Hw 4.2Hw

CH (cm) 31.4Hw 30.3Hw 30.7 Hw

36Sf

28.6Hw 34.2Hw 34.6Hw 31.6Hw 27.3Hw

28Tt

30.3 Hw 30.1Hw 21.2Hw

One Year Monitoring 2015

Two Year Monitoring 2016

Three Year Monitoring 2017

Sept

2016

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Ref

SSD 6.6Hw 9.7Hw

5Tt

6.2Hw 9.2Hw 7.7Hw 8.8Hw 8.5Hw 9.4Hw

3Tt

9Hw 7.5Hw 4Hw

CH

(cm)

24.6Hw 29.3H

w 28Tt

28.3Hw 28.2Hw 30.4H

w

29.6H

w

27.4Hw 28.5Hw

11Rm

31.8Hw 29.8Hw 19Hw

Sept

2015

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Ref

SSD 9.5Hw 8Hw 10Hw 8.4Hw 8.6Hw 8.2Hw 8.9Hw 6.5Hw 5.1Hw 5.6Hw <1Hw

CH

(cm)

17.7Hw 17.6Hw 18.2Hw 18.2H

w

20.2H

w

18Hw 19.4Hw 19.1Hw 17.2Hw 17.1Hw 0Hw

Public Service Announcement

Thank you! Any questions?

Heather Maggio heather.maggio@tampagov.net

813-274-8371

Serra Herndon sherndon@tampabaywatch.org

727-867-8166 ext. 227

Contact Info