Appendix_6_-_Comprehensive_Physical_Monitoring_Plan.pdf

U.S. Army Corps of Engineers – Jacksonville District

Physical Monitoring Plan

Pinellas County

Sand Key Beach Nourishment (0238664-001-JC) Modification No. 0238664-009-JN

Treasure Island and Long Key Beach Nourishment (0221569-016-JN) Modification No. 0221569-017-JN

John's Pass Maintenance Dredging (0270453-003-JN) Modification No. 0270453-004-JN

June 21, 2017

Beach Profile, Borrow Area, and Maintenance Dredging Surveys and Reporting

A . Scope of Monitoring: This monitoring scope is presented to document Pinellas County’s comprehensive, long-term monitoring plan for assessment of the performance of the Pinellas County Shore Protection Project’s beach nourishment and maintenance dredging projects including: Sand Key Beach Nourishment, Long Key and Treasure Island Beach Nourishment, and Johns Pass Maintenance Dredging.

B. Monitoring Plan Objectives:

1. Ensure a spatially and temporally consistent beach and borrow area survey program on a biennial basis over the full length of the Pinellas County Shore Protection Project plus control areas adjacent to fill areas.

2. Establish a comprehensive beach profile database which will provide for easy data access and will be compatible with all existing State and federal agency database and GIS applications.

3. Provide greater flexibility than the current project-specific survey schedule to allow for the assessment of acute erosion events due to storms or other causes.

C. Monitoring Plan Components:

1. Biennial Topographic and Bathymetric Surveys. This component will consist of project-wide profile surveys at approximately 1,000 ft intervals extending from Clearwater Pass to the southern extent of the Sand Key Segment plus control area and the entire extents of Treasure Island and Long Key (Reference Monuments R52 – R115 and R126 - R166). Survey profiles will be referenced to specific monuments (i.e. Range 0+00 = monument location). Project and monitoring area extents are given in Table 1 below.

kennycarmola_i New Stamp

2. The profiles will extend form a position landward of the monument sufficient to including existing dune features or other topographic features located on the beach proper out to a minimum of 3,000 ft offshore (from the landward onshore data point) or to -20 ft NAVD88 (approximate depth of closure) whichever is reached first. Elevations will be determined minimally at 25 ft intervals along the full length of the profile. If Pinellas County, through its engineering analysis based on historical beach data, determines that a beach profile has remained significantly constant up to specific distance landward of the monument, may choose to provide a statement of adjustment to reduce the length of said profile on the following biennial survey. At a minimum, however, adjusted profiles will be surveyed again per the original specifications to a length of 3,000 ft offshore or to -20 ft of depth, for every other biennial survey.

3. The monitoring surveys shall be conducted during a spring or summer month and repeated as close as practicable during that same month of the year.

4. Surveys will be conducted to assess the erosional effects of major storms or other acute erosion events. The timing and extent of these surveys will be determined jointly by Pinellas County, FDEP, and the Corps of Engineers. These surveys would serve to complement, not duplicate, any storm effects assessments that may be underway by other state, federal, or local agencies.

Table 1: Beach Fill Monitoring Information

Nourishment Sites

Project Area

Monitoring Area (at a minimum)

Survey Locations

Within Monitoring

Area

Landward and Seaward Extent of Profiles to be

Surveys

Sand Key R55 – R66 & R71A – R109

R52 – R115 Each of FDNR monuments

Position landward of the monument sufficient to include existing dune features and other topographic features located on the beach proper out to a minimum of 3,000 feet offshore or to -20 feet NAVD88 whichever is reached first

Treasure Island

R126A – R128A & R136

– R142

R126 – R143 Each of FDNR monuments

Long Key R144 – R146 & R160 – R166

R144 – R152 & R155 –

R166

Each of FDNR monuments and USACE monuments

D. Specific Physical Monitoring Requirements for all Pinellas County Joint Coastal Permits:

1. Beach and Offshore Surveys.

a. Topographic and bathymetric profile surveys of the beach and offshore shall be conducted within 90 days prior to commencement of construction of a beach nourishment event, within 60 days following completion of construction, and biennially thereafter beginning with the next regularly scheduled county-wide biennial monitoring survey. A pre-construction survey of the project area to receive beach fill may use surveys conducted for purposes of construction bidding, contracting or construction management. The post-construction survey of the beach fill may use surveys and other information collected periodically during construction for purposes of construction management and payment. Alternatively, the post-construction survey may consist of a single beach-offshore profile survey event of the project monitoring area conducted within 60 days after completion of beach fill placement.

b. Pre-construction surveys for hotspot nourishment placing volumes less than 15,000 cubic yards of sand will not be required, provided no changes to the permitted sand source is requested.

c. If the time period between the post-construction survey and the first biennial monitoring survey is less than six months, then the Permittee may at their discretion, postpone the first monitoring survey until the next regularly scheduled biennial event.

d. The pre- and immediate post-construction monitoring event shall include profile surveys at each of the Department of Environmental Protection’s DNR reference monuments with the bounds of the beach fill area and also shall include the next profile locations on each adjacent side to the beach fill area.

e. In addition to the above proposed survey intervals, additional survey events will be conducted following significant storm events. The threshold for initiating surveys following storm events will be established jointly by Pinellas County, FDEP, and the Corps of Engineers.

f. All work activities and deliverables for the biennial monitoring surveys shall be conducted in accordance with the latest update of the Division of Water Resource Management (DWRM) Monitoring Standards for Beach Erosion Control Projects, Sections 01000 and 01100. This document is available on the Publication/Technical Reports page of the FDEP-DWRM website.

2. Offshore Borrow Area Surveys.

a. Bathymetric surveys of the borrow area(s) shall be conducted within 90 days prior to commencement of construction and again within 60 days following completion of construction of the project concurrently with the beach and offshore survey required above.

Alternatively, the pre-construction and the post-construction surveys of the borrow area may consist of surveys and other information collected during construction for purposes of construction management. A prior design survey may be submitted for the pre-construction survey.

b. Survey grid lines across the borrow area(s) shall be spaced to provide sufficient detail for accurate volumetric calculations but spaced not more than a maximum of 500 ft apart, and shall extend a minimum of 500 ft beyond the boundaries of the borrow site. In all other aspects, work activities and deliverables shall be consistent with the Department’s Monitoring Standards for Beach Erosion Control Projects, Section 01200.

3. Inlet Borrow Area Surveys.

a. Bathymetric surveys of borrow area(s) located at inlet channels and shoals shall be conducted within 90 days prior to commencement of construction and again within 60 days following completion of construction of the project. Thereafter, monitoring surveys of the inlet borrow area(s) shall be surveyed concurrently with the biennial beach and offshore surveys required above. A prior design survey may be submitted for the pre-construction survey.

b. Survey grid lines across the borrow area shall be spaced 500 ft apart and shall extend a minimum of 500 ft beyond the boundaries of the borrow site. For borrow sites located in tidal inlet shoals, bathymetric surveys of the entire shoal complex, including any attachment bars, shall be conducted unless otherwise specified by the Department based upon the size of the shoal and the potential effects of the dredging on inlet processes.

• For Johns Pass, the shore-parallel survey lines shall extend from approximately R- 123 to R-130.

• For Blind Pass, the shore-parallel survey lines shall extend from approximately R- 142 to R-146.

• For Pass-a-Grille, the shore-parallel survey lines shall start at approximately R-165 and extend approximately 6,000 feet to the south.

There should be at least 4 profile lines passing through the ebb shoal borrow area. Work activities and deliverables shall be consistent with the Department’s Monitoring Standards for Beach Erosion Control Projects, Section 01200.

4. Monitoring Reports.

a. The permittee shall submit and engineering report and the monitoring data to the Department within 120 days following completion of the post-construction and each biennial monitoring survey.

b. The report will summarize and discuss the data, the performance of the beach fill project, and identify erosion and accretion patterns within the monitored area. The results shall be analyzed for patterns, trends, or changes between annual surveys and cumulatively since project construction. In addition, the report will include a comparative review of project performance to performance expectations and identification of adverse effects attributable to the project.

The report will specifically include:

1. A record of the volume and location of all beach fill or inlet sand bypassing material placed within the project area;

2. The volume and distribution of infilling of the inlet borrow area(s) and changes of the inlet channels and shoals;

3. The volume and percentage of advance nourishment lost since the last beach nourishment project as measured landward of the MHW line of the most recent survey;

4. The most recent MHW shoreline positions (feet) in comparison with the design profile at each individual monument location;

5. The MHW shoreline position changes (feet) relative to the pre-construction survey at each individual monument location for all the monitoring periods;

6. The total measured remaining volume (cubic yards) in comparison with the total predicted remaining volume (cubic yards) above the MHW line and above the Depth of Closure for the entire project area over the successive monitoring periods;

and,

7. Other shoreline position and volumetric analysis the Permittee or engineer deem useful in assessing, with quantitative measurements, the performance of the project.

c. The report will include computations, tables and graphic illustrations of volumetric and shoreline position changes for the monitoring area. An appendix shall include superimposed plots of the two most recent beach profile surveys, the design profile, and pre- and post-construction beach profile at each individual reference monument location.

d. An updated sediment budget shall be provided prior to each beach nourishment event that uses the Pass-a-Grille, Johns Pass or Blind Pass inlet channels and ebb shoal borrow areas as a sand source. The sediment budget shall be included in the biennial engineering report using the data required by the physical monitoring plan.

e. A digital copy of the monitoring report and a digital file of the survey data shall be submitted to the Division of Water Resource Management’s Compliance Officer in Tallahassee. Failure to submit reports and data in a timely manner constitutes grounds for revocation of the permit.

When submitting monitoring information to the Department, a transmittal cover letter clearly labeled with the following: “This monitoring information is submitted in accordance with the approved Monitoring Plan for Permit No. XXXXXXX-XXX-XX, Project Name, for the monitoring period [XX].”

f. Storm Monitoring Reports. A report detailing and analyzing the results from Post-Storm hydrographic monitoring conducted during the previous year will be submitted with the annual reports.

Attachment No. 11

Grundl_R Stamp

Grand Canal Maintenance Dredging

July 2021

Pursuant to 62B‐41.005(16), F.A.C., physical monitoring of the project is required through acquisition of project‐specific data to include, at a minimum, topographic and bathymetric surveys of the beach, and dredge area, and engineering analysis.

The monitoring data is necessary in order for both the project sponsors and the Department to regularly observe and assess, with quantitative measurements, the performance of the project, any adverse effects which have occurred, and the need for any adjustments, modifications, or mitigative response to the project. The scientific monitoring process also provides the project sponsor and the Department with information necessary to plan, design and optimize subsequent follow‐up projects, potentially reducing the need for and costs of unnecessary work, as well as potentially reducing any environmental impacts that may have occurred or be expected.

A schedule of monitoring events is presented below in Table 1., Northern Shell Key monitoring area illustrated in Figure 1., and monitoring profile locations are specified in Table 2.

Table 1. Physical Monitoring Schedule

Monitoring Event

Disposal Area Topographic &

Bathymetric Surveys

Dredge Area & Northern Shell Key

Topographic & Bathymetric Surveys

Engineering Monitoring

Reports

Pre-Construction x x

Post-Construction x x x Year 1

In accordance with previously established county-wide coastal monitoring x x Year 2 x x Year 3 x x

Year 4 Year 5 x x

Grundl_R Stamp

1. Disposal Area Topographic and Bathymetric Surveys (Beach Profile Surveys) Topographic and bathymetric profile surveys of the beach and offshore shall be conducted within 90 days prior to commencement of construction, and within 60 days following completion of construction of the project. Thereafter, monitoring surveys shall be conducted in accordance with the established Pinellas County Physical Monitoring Plan for FDEP Permit No. 0221569‐016‐JN (June 2017) until the next beach disposal event. If the time period between the immediate post‐ construction survey and the first annual monitoring survey is less than six months, then the Permittee may request a postponement of the first monitoring survey until the following monitoring period.

A prior design survey of the beach and offshore may be submitted for the pre‐ construction survey if consistent with the other requirements of the permit. When pre‐ or post‐construction surveys are conducted separately from the annual monitoring surveys, they will only cover the fill disposal area plus one additional R‐ monument on either side of the project area with the maximum survey extents being R‐159 to R‐166.

All work activities and deliverables shall be conducted in accordance with the latest update of the Department’s Monitoring Standards for Beach Erosion Control Projects.

2. Dredge Area & Northern Shell Key Surveys Topographic and bathymetric surveys of Northern Shell Key and the Grand Canal dredge area(s) shall be conducted within 90 days prior to commencement of construction, and within 60 days following completion of construction of the project.

Thereafter, monitoring surveys shall occur annually for three years post‐ construction, then every other year until the next maintenance dredging event or permit expiration. A prior design survey may be submitted for the pre‐construction survey if consistent with the other requirements of this permit.

Northern Shell Key topographic and bathymetric profile surveys shall be collected at the monitoring stations listed in Table 2 as well as along the MHW within the survey area. At a minimum, profiles shall start at the monitoring station or edge of vegetation, whichever is more landward and extend to the limits of previously surveyed lines as shown in Figure 1.

Survey grid lines across the dredge areas shall be spaced to provide sufficient detail for accurate volumetric calculations of the dredge areas as well as the Northern Shell Key/Grand Canal monitoring area but spaced not more than a maximum of 200 feet apart and shall extend a minimum of 500 feet beyond the boundaries of the dredge areas. Figure 1 displays tracklines that have been previously surveyed in this area to serve as a reference for planning future survey events. In all other aspects, work activities and deliverables shall be consistent with the Department’s Monitoring Standards for Beach Erosion Control Projects.

3. Engineering Monitoring Report /Survey Data Transmittal

An engineering report and the monitoring data will be submitted to the JCP Compliance Officer within 90 days following completion of the post‐construction survey. Annual physical monitoring reports for Northern Shell Key and Grand Canal Dredge areas will summarize and discuss the data, the performance of the maintenance dredging project, and identify erosion and accretion patterns within the monitored area. In addition, the report will include a comparative review of project performance to performance expectations and identification of adverse impacts attributable to the project. The report shall specifically state:

A record of the volume dredged and fill placement location

The MHW shoreline position changes (ft.) relative to the pre‐construction survey at each individual Northern Shell Key profile location

A figure depicting the Northern Shell Key MHW locations

The total volume accumulated within the dredge area(s) The volume and distribution of infilling of the dredge area(s) since construction Other shoreline position and volumetric analysis the Permittee or engineer deem useful in assessing, with quantitative measurements, the performance of the Grand Canal Maintenance Dredging project.

Appendices will include plots of survey profiles and graphical representations of volumetric and shoreline position changes for the monitoring area. Results will be analyzed for patterns, trends, or changes between annual surveys and cumulatively since project construction. The monitoring report and survey data will be submitted electronically to the JCP Compliance Officer.

Table 2. Northern Shell Key Monitoring Profiles

Figure 1. Northern Shell Key/Grand Canal Monitoring Area.

ID Northing Easting Azimuth

SL1 1215617.3 420460.8 10

SL1.5 1215636.1 420115.7 9

SL2 1215707.2 419755.1 7

SL3 1215670.8 419402.1 6

SL3.5 1215166.6 419132.1 345

SL4 1215252.5 418644.8 345

SL5 1215194.4 418141.9 12

SL5.5 1215263.5 417558.5 12

SL6 1215654.7 417016.2 354

SL7 1215599.3 416272.1 344

SL8 1215241.0 415943.4 317

SL9 1214932.9 415853.2 298

SL10 1214666.5 415763.3 274

SL11 1214188.9 415673.4 274