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 2
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Plot 9
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 5
Plot 6
Plot 7
Plot 8
Plot 9
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 2
Plot 3
Plot 4
Plot 5
Plot 6
Plot 7
Plot 8
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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Plot 10
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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Plot 2
Plot 3
Plot 4
Plot 5
Plot 6
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Plot 8
Plot 9
Plot 10
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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Plot 2
Plot 3
Plot 4
Plot 5
Plot 6
Plot 7
Plot 8
Plot 9
Plot 10
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 [email protected]
813-274-8371
Serra Herndon [email protected]
727-867-8166 ext. 227
Contact Info