Rookery at Perico Seagrass Advance Mitigation

ROOKERY AT PERICO SEAGRASS ADVANCE MITIGATION

Mitigation Establishment Criteria Report

May 17, 2013

ROOKERY AT PERICO SEAGRASS ADVANCE MITIGATION

Table of Contents

EXECUTIVE SUMMARY ...... I

1.0 INTRODUCTION ...... 1.1

2.0 COMPENSATORY MITIGATION (DIRECT IMPACTS) ...... 2.2 2.1 MANGROVE FOREST DESIGN AND IMPLEMENTATION ...... 2.2 2.2 MONITORING METHODOLOGY ...... 2.2 2.3 SUCCESS CRITERIA ...... 2.4 2.4 LONG-TERM MAINTENANCE ...... 2.5

3.0 HABITAT CREATION MITIGATION CREDITS ...... 3.5 3.1 SEAGRASS HABITAT CREATION ...... 3.5 3.1.1 Design Details ...... 3.5 3.1.2 Implementation Options ...... 3.7 3.1.3 Mitigation Credit Assessment (UMAM) ...... 3.9 3.1.4 Monitoring Details ...... 3.13 3.1.5 Mitigation Credit Determination ...... 3.17 3.1.6 Long-Term Protection ...... 3.19 3.2 MANGROVE HABITAT CREATION ...... 3.19 3.2.1 Design Details ...... 3.19 3.2.2 Mitigation Credit Assessment (UMAM) ...... 3.20 3.2.3 Monitoring Details ...... 3.22 3.2.4 Mitigation Credit Determination ...... 3.24 3.2.5 Mangrove Creation Areas Long-Term Protection ...... 3.25

4.0 BIBLIOGRAPHY ...... 4.25

LIST OF APPENDICES

APPENDIX A FIGURES ...... A.0 A.1 Seagrass Donor Area Exhibit ...... A.1

APPENDIX B ATTACHMENTS ...... B.0 B.1 Perico Preserve Habitat Restoration Modeling Study Prepared by Coastal Planning and Engineering, Inc. December 2012 ...... B.1 B.2 Uniform Wetland Mitigation Assessment Worksheet - Parts I and II ...... B.2

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Executive Summary

This document has been prepared to provide supporting information for the Southwest Florida Water Management District (SWFWMD) and U.S. Army Corps of Engineers (USACE) relative to the establishment and release of mitigation credits for the project known as Rookery at Perico Seagrass Advance Mitigation. This document was prepared as a separate document to focus on the establishment of mitigation credits, a key component of the project. The purpose of this document is to provide a framework for the generation, monitoring, success determination, and release of mitigation credits that is applicable for both the SWFWMD and USACE.

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1.0 Introduction

This document has been prepared to outline the process by which the regulatory permits may authorize the generation and release of mitigation credits for the Rookery at Perico Seagrass Advance Mitigation project. For SWFWMD, this will entail the establishment of a regional offsite mitigation area (ROMA). This document will be provided to both the SWFWMD and USACE to be incorporated into the permit conditions for the applicable permits to be issued. The Applicant acknowledges that this is a unique project and that this document may generate feedback from both the review and resource agencies. The Applicant desires to work with the agencies to establish a mitigation credit generation and release criteria that satisfies the regulatory requirements and provides a predictable mitigation credit quantity for the Applicant.

In addition to habitat creation and restoration activities proposed for the purpose of generating mitigation credits, this document will also discuss the details associated with the design, monitoring, and success of the compensatory mitigation for project construction related impacts (i.e. mangrove forest excavation) discussed within the “Support Narrative” that accompanied both the USACE Individual Permit application and the SWFWMD Individual ERP application. Please reference Attachment B of the “Support Narrative and Documentation for SWFWMD ERP Application” or “Support Narrative and Documentation for USACE Application – Revised May 2013” for the Construction Plans or Project Plans, respectively, referenced herein.

The following aspects and criteria will be discussed in this document:

 Compensatory mitigation – Mangrove forest creation

 Design and implementation

 Monitoring methodology

 Success criteria

 Long-term maintenance

 Habitat creation mitigation credits – Seagrass and mangrove

 Habitat creation design

 Implementation options

 Conceptual mitigation credit assessment

 Monitoring methodology

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 Mitigation credit determination/quantification

 Mitigation credit release schedule/details

 Long-term maintenance

2.0 Compensatory Mitigation (direct impacts)

The proposed project requires 0.41 acre of impact to the mangrove forest adjacent to Perico Bayou for two flushing channel cuts, as described in the “Rookery at Perico Seagrass Advance Mitigation – Support Narrative and Documentation for SWFWMD ERP Application” and “Rookery at Perico Seagrass Advance Mitigation – Support Narrative and Documentation for USACE Application”. The calculated Uniform Mitigation Assessment Method (UMAM) functional loss associated with the impacts is 0.12. The Applicant proposes to mitigate for this impact through onsite mangrove forest creation.

2.1 MANGROVE FOREST DESIGN AND IMPLEMENTATION

The Applicant proposes to provide compensatory mitigation for the mangrove impacts through the establishment of a “Mangrove Mitigation Zone” along the fringe of the “Seagrass Creation Area” as shown on the Construction Plans. The 0.5 acre mangrove creation area will be constructed as a 20-foot wide and 1,089-foot long linear fringe ranging from one (1) foot below mean high water (0.33’ NAVD) to one (1) foot above mean high water. It is anticipated that the portion above mean high water will develop into a black mangrove dominated forest and a red mangrove forest will develop below mean high water. It is likely that a transition area containing both species will develop near mean high water.

Following the finish grading activities for the basin, vegetation will be installed along the upper elevations to minimize the potential for erosion within and into the Mangrove Mitigation Zone. As shown on the planting specifications in the Construction Plans, 439 red mangrove propagules will be planted on five-foot centers and 110 3-gallon red mangroves will be planted on ten-foot centers below mean high water and 108 two-inch (minimum) liner black mangroves will be planted on ten-foot centers.

2.2 MONITORING METHODOLOGY

The following monitoring methodology has been designed to sufficiently monitor the Mangrove Mitigation Zone to determine whether the mitigation activities are progressing towards and eventually meeting the success criteria required by the regulatory permits.

A mitigation construction completion/baseline report will be prepared and submitted to SWFWMD/USACE for approval within 30 days of the completion of planting activities. Once

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approval is received from SWFWMD/USACE, the monitoring and maintenance period for the Mangrove Mitigation Zone will commence.

Monitoring events will be conducted for the Mangrove Mitigation Zone. The following monitoring events are proposed; time zero, time zero + 6 months, time zero + 1 year, time zero + 2 years, time zero + 3 years, time zero + 4 years, and time zero + 5 years. However, once the Mangrove Mitigation Zone achieves the success criteria and is approved, the Applicant may choose to discontinue future monitoring events. The monitoring will be conducted by a qualified professional. The mangrove monitoring will consist of a qualitative assessment and quantitative assessment, as detailed below. A report summarizing the conditions observed during the monitoring event(s), the maintenance activities completed during the previous year, maintenance activities recommended during the next year, and a discussion relating observed conditions to the success criteria will be prepared. The monitoring report will be prepared and submitted to SWFWMD/USACE within 30 days following the completion of the annual monitoring events (up to 5 annual reports).

The qualitative assessment will include a visual inspection of the entire mitigation area to note general observations of reduced/exceptional mangrove growth, estimated nuisance/invasive species cover, areas of erosion, and fauna utilization.

The quantitative assessment will provide data suitable for estimating areal percent cover by mangroves, areal percent cover by nuisance/exotic species, and annual growth rate. Quantitative monitoring will be conducted using line intercept transects in randomly selected locations within the Mangrove Mitigation Zone. Detailed monitoring procedures are as follows:

1. The MHW line will be utilized as a linear baseline through the area and will be stationed in 10-foot sections starting at zero at the southeast terminus.

2. Using GIS, a minimum of 15 transects will be generated at random 10-foot stations oriented perpendicular to the baseline.

3. Each monitoring transect will be located in the field and the start and end points will be marked at the edge of mangrove canopy cover.

4. A measuring tape will be extended between the markers with the zero (0) point on the waterward end of the transect.

5. Starting at zero, the species and height of the nearest mangrove individual to the line will be collected every 0.5 meter. This data will be used to calculate annual growth rate.

6. Starting at zero, continue along the entire transect line noting where any canopy or basal portion of plants cross or touch the line. Record the measurements and species. Where two species cross or touch at the same location, record both species. This data will be used to calculate percent cover for mangroves and nuisance/exotic species.

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Representative photographs will be taken from a minimum of five (5) fixed photograph stations established at the time of planting completion. In addition, a photograph of each monitoring transect line will be taken.

2.3 SUCCESS CRITERIA

The Mangrove Mitigation Zone will be considered successful at the time the success criteria are met. The mitigation will be considered successful once the area is documented as meeting the criteria below during an annual monitoring event and is subsequently inspected and approved by SWFWMD/USACE. The success criteria must be met within 5 years or the Applicant shall propose a remediation plan detailing activities to be implemented to meet the success criteria. The success criteria shall include the following:

a) The mitigation area meets the definition of a mangrove swamp (FLUCCS:612) through dominance of mangrove species;

b) The mitigation area can be determined to be a wetland or other surface water pursuant to Chapter 62-340, F.A.C.;

c) Estimated areal percent cover by mangrove species for the entire mitigation area is 50 percent or greater;

d) A positive annual growth rate is documented; and

e) Cover by nuisance and invasive species is less than 5 percent.

A specified height of mangroves within the mitigation area is not a success criteria parameter. It is understood that the mangroves will likely not reach their full height potential within the 5-year monitoring period. However, the time lag used to calculate the required compensatory mitigation assumes an 11 – 15 year time lag to provide adequate time for the mangrove canopy to develop. It is unreasonable to monitor the mitigation area for 11+ years to document mangrove height if the mitigation area is demonstrating sufficient growth and habitat development based on the areal cover estimate and annual growth rate calculation and trending toward a climax mangrove forest.

The Mangrove Mitigation Zone is designed to occur within a 20-foot wide area centered along the mean high water (0.33 ft. NAVD); however, the Mangrove Mitigation Zone boundary shall be flexible allowing the mitigation area to include areas above and below the 20-foot zone to be included in the Mangrove Mitigation Zone if necessary to meet the 0.5 acre mitigation requirement. At the time the Mangrove Mitigation Zone is deemed successful, a sub-meter DGPS shall be utilized to collect points denoting the limits of the Mangrove Mitigation Zone. Points collected shall be spaced a maximum of 30 feet apart and shall adequately capture the limits of the zone. The points will be utilized to generate a boundary of the total successful mangrove mitigation area.

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Any portion of the successful Mangrove Mitigation Zone beyond the required 0.5 acre of compensatory mitigation for direct impacts will be added to the Mitigation Credits available to Permittee. See Section 3.2 below for additional details.

2.4 LONG-TERM MAINTENANCE

The Mangrove Mitigation Zone will be maintained in perpetuity following the initial installation of plants. An appropriate maintenance schedule will be developed to minimize the presence of nuisance/invasive species through the application of approved, systemic herbicides and/or hand removal. The maintenance schedule will minimize the application of herbicides through active monitoring, allowing maintenance events to be completed when necessary. In addition to the control of nuisance/invasive species, the Applicant will implement practices to keep the Mangrove Mitigation Zone free from human disturbance or destruction to the greatest extent practical.

The mitigation area will be maintained at the success criteria by the Applicant in perpetuity. In addition, the Mangrove Mitigation Zone will be included within the conservation easement boundary.

3.0 Habitat Creation Mitigation Credits

This section describes the habitat creation design, implementation options, mitigation credit assessment, monitoring methodology, mitigation credit determination, mitigation credit release schedule/details, and long-term maintenance for each of the proposed habitat creation types.

3.1 SEAGRASS HABITAT CREATION

The creation and establishment of a tidal basin dominated by seagrass is the primary goal of the proposed project. The purpose of the seagrass habitat creation is to provide a reserve of mitigation credits that other governmental agencies within Manatee County can draw upon to offset seagrass impacts associated with their projects.

3.1.1 Design Details

As shown in the Construction Plans, a 16.40 acre basin has been excavated from fallow farm fields. The basin will be connected to the tidal waters of Perico Bayou through the excavation of two flushing channels. Both the channels and the basin will be excavated to a depth of -2 feet NAVD. This depth was identified as a suitable depth for seagrass establishment based on the presence of healthy, continuous seagrass cover at this elevation within Perico Bayou. Thalassia testudinum and Halodule wrightii have been identified growing at elevations near -2 feet NAVD in Perico Bayou. The seagrass creation area totals 12.21 acres, corresponding to the area encompassing the elevation range of -1.5 feet NAVD to -2.0 feet NAVD. Also included is the area at elevation -2.7 feet NAVD that encircles the Rookery Island.

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The Seagrass Creation Area basin has been designed with broad, gentle slopes (10:1) to allow the creation of mangrove, marsh, and upland habitats beneficial to wildlife utilization adjacent to the Seagrass Creation Area. The adjacent habitats have been designed and located to provide erosion protection, shelter, and potential nesting habitat for species that may utilize the basin. Through connectivity with other Perico Preserve restoration areas, a network of wildlife corridors will be established that extend from Perico Bayou to the interior mangrove swamps of Perico Island.

The creation of a water environment suitable for the seagrass establishment is a critical component for the Seagrass Creation Area. The water environment includes multiple parameters including tidal range/duration, flushing times, and erosion/scour. To maximize the probability that suitable seagrass growing conditions will exist within the basin, the design of the basin is based on replicating the conditions within the adjacent portion of Perico Bayou where healthy, continuous seagrass is established. In other words, if the basin is designed such that water environment conditions (e.g. temperature, salinity, and tide range) within the basin are similar to Perico Bayou, water environment conditions in the basin should be suitable for seagrass establishment. To facilitate the design of the Seagrass Creation Area, the Applicant contracted with Coastal Planning and Engineering, Inc. to prepare the “Perico Preserve Habitat Restoration Modeling Study” in December 2012, reference Attachment B.1. The modeling study focused on a tidal exchange analysis. The tidal exchange analysis provides a comparison between the proposed basin and Perico Bayou.

Multiple flushing model scenarios were developed, ran, and analyzed to assess the proposed flushing and flow conditions. Per standard practice, a No-Action Scenario was assessed to document baseline conditions if no improvements are made. Two design alternatives were evaluated that included a connection to and the restoration of the mosquito ditch flowing from the southwestern portion of the basin through the mangrove swamp, under S.R. 64, and into Spoonbill Bay. A fourth model was assessed that included blocking the flow of the mosquito ditch, which served two purposes, demonstrating the conditions if the restored ditch silted in or if the ditch connection was abandoned and not constructed.

The fourth model (October 12 Design with Clogged Mosquito Ditch) serves as the model that is applicable to the design proposed herein. Two flushing scenarios were assessed for this model alternative, one with a tracer in the seagrass basin only (Scenario A) and one with a tracer in the seagrass basin as well as Spoonbill Bay and Perico Bayou (Scenario B). The model results under Scenario B show the middle of the seagrass basin (Rookery Middle) flushes the initial tracer to a concentration equal to one percent (1%) of the original concentration within 11.5 days. Within the middle of Perico Bayou outside the seagrass basin (Rookery Outside), the model shows 12.1 days to flush the initial tracer to a concentration equal to one percent (1%) of the original concentration. These flushing results demonstrate that flushing within the seagrass basin will be similar to or improved beyond the flushing that exists within Perico Bayou outside of the seagrass basin, where healthy continuous seagrass currently exists.

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The model also concluded that “current speeds within the flushing channels and mosquito ditch throughout a tidal cycle are less than 0.2 feet per second” and that “based on the mean sediment size determined during the granularmetric analysis of the sand samples collected from the restoration area (Appendix C), 0.18 millimeters, the mean velocity for stable channel design is 0.6 feet per second (Vanoni, 1977). As a result, sediment is not expected to mobilize in these areas.” Therefore, it is anticipated that water quality within the seagrass basin or Perico Bayou will not be adversely affected nor will sediment scour or re-suspension be an issue.

3.1.2 Implementation Options

Considering that the Seagrass Creation Area is proposed as up-front mitigation for future impacts, the Applicant has flexibility in regards to timing associated with the establishment of seagrass cover. The Applicant desires to establish seagrass cover as soon as possible while minimizing cost. In addition, it will be beneficial to allow the sediments in the Seagrass Creation Area a period of exposure to the tidal waters to normalize sediment chemistry and structure. Therefore, the Applicant proposes three implementation methods that may be utilized separately or combined. The options are described below.

3.1.2.1 Natural Recruitment

The natural recruitment option entails excavation of the Seagrass Creation Area and flushing channels. Following the excavation, the Applicant will monitor the area to note the recruitment of seagrass. This method is most conducive to the establishment of Halodule wrightii, since this species is an active colonizer and has a faster rate of growth. It is anticipated that natural recruitment will occur, because dense Halodule wrightii cover is present immediately outside the proposed flushing channels. The potential for seagrass to colonize the seagrass basin solely through recruitment is believed to be high; however the amount of time required is highly variable and very difficult to predict (Fonseca et al., 1998). The Applicant acknowledges that this option may take many years (>5 years) to establish large areas of seagrass cover.

3.1.2.2 Small-scale Planting

This option will entail the installation of seagrass planting units in multiple locations within the Seagrass Creation Area. The goal is to provide “seed units” that will grow and expand throughout the area and augment the natural recruitment process. Halodule wrightii, Thalassia testudinum, or both species could be planted as part of this option. This option could include the installation of closely-spaced (i.e. 3-foot centered) planting units in a small area (colony) or sparsely scattered (i.e. 20-foot centered) planting units over a large area. The timeline for establishment of seagrass cover using this option will be dependent on the species planted and the quantity of units transplanted.

At the time the Applicant chooses to implement a seagrass transplanting event, a written notice will be provided to SWFWMD and USACE describing the general location of the planting units, quantity of units to be harvested/planted, proposed transplanting date, proposed donor location, and source of backfill sediment (if necessary). Following each transplanting event, a written

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notice will be provided to SWFWMD and USACE summarizing the area planted, number of units harvested/planted, dates of planting, and location of the harvested seagrass plugs within the seagrass donor areas.

3.1.2.3 Large-scale Planting

This option will entail the installation of seagrass planting units across the entire Seagrass Creation Area or a large portion thereof. The goal is to provide immediate seagrass cover that will grow and coalesce throughout the area. Halodule wrightii, Thalassia testudinum, or both species could be planted as part of this option. This option could be implemented as part of a modified compressed succession approach, whereby Halodule wrightii would be transplanted into the Seagrass Creation Area at a high density and allowed to coalesce over a few growing seasons. Once sufficient cover by Halodule wrightii has stabilized and colonized, a seagrass transplanting event would be conducted for Thalassia testudinum. The timeline for establishment of seagrass cover using this option will be dependent on the species planted and the quantity of units transplanted. It is anticipated that this option would significantly shorten the time period required for the establishment of dense seagrass cover.

3.1.2.4 Planting Methods

All seagrass planting activities will be conducted under the supervision of Manatee County or their designated, qualified consultants/contractors. The “modified shovel method” and “pneumatic plugger method” are the proposed planting methods to be utilized to transplant seagrass planting units within the Seagrass Creation Area. However, the Applicant requests the flexibility to use other methods (e.g. peat pot, bare root, PVC corer) that have shown demonstrated success for seagrass transplanting and are not likely to cause adverse damage to seagrass donor areas.

All transplanted seagrass planting units (donor seagrass) will be harvested from the proposed “Seagrass Donor Area” shown on Figure A.1 – Seagrass Donor Area Exhibit or from other donor sites to be identified and approved prior to seagrass harvesting. It is anticipated that the Seagrass Donor Area located adjacent to the project area, as shown on the exhibit referenced above, will provide a sufficient quantity of Halodule wrightii donor material. However, additional nearby donor areas may be required to provide sufficient quantity of quality Thalassia testudinum donor material. Seagrass donor material will only be harvested from areas with a minimum Braun-Blanquet Cover Abundance (BBCA) of “4”, see Section 3.1.4.2.II. for details on the BBCA scale. The locations and characteristics of additional donor areas will be provided to SWFWMD and USACE for review and approval prior to commencing harvesting activities. The minimum spacing between donor seagrass planting units harvested from the seagrass donor areas is five (5) feet. Planting units will be harvested in a systematic way, along transects, such that the locations of harvested planting units can be tracked and monitored following harvesting. All harvested seagrass planting units will be kept adequately saturated and protected from desiccation during the transplanting activities. All harvested units will be planted the same day that they are harvested. The proposed seagrass planting methods are described below.

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The proposed transplanting method for Halodule wrightii is the “modified shovel method” (Montin and Dennis, 2003). This method was developed by Stantec for use with shallow-rooted seagrasses and has been used successfully in multiple locations, including Tampa Bay (Port Manatee) and Biscayne Bay. Seagrass planting units will be harvested with a square shovel (approx. 9.5 inches by 11.5 inches) that has been modified to cleanly cut the seagrass rhizomes and allow water to pass through it. The units are placed on trays and transported to the planting area and installed flush with the surrounding sediments using the same modified shovel. Backfilling of harvested areas is not necessary with this method, because the holes are broad and shallow.

The proposed transplanting method for Thalassia testudinum is the “pneumatic plugger method”. This method uses a Stantec-patented 8-inch core plugger that has been optimized for the efficient extraction of deeper-rooted seagrass species with minimal disturbance through the use of compressed air to relieve suction pressure generated by the removal of sediment underwater. The sharp edges of the plugger cleanly sever the seagrass rhizomes to reduce stress of the planting unit and the 8-inch width allows the collection of a sufficient number of apical meristems that are critical to the growth and expansion of seagrass planting units. Fonseca highlighted the importance of transplanting rhizome apical meristems to provide a source of new shoots and horizontal growth; going further to suggest that the number of short shoots along a long shoot should be maximized to derive benefits from the clonal nature of the plants (Fonseca et al., 1998).

The “pneumatic plugger method” includes the use of the plugger and a specially-designed canister used for transport of the harvested units to the planting location. The canister keeps the soil matrix intact and saturated from the time of harvest until planting.

The holes resulting from pneumatic plugger harvesting will be backfilled with clean, sediment to minimize potential for the enlargement of holes from erosion. Backfill material may be sourced from the seagrass planting holes within the Seagrass Creation Area or from a suitable external source.

3.1.3 Mitigation Credit Assessment (UMAM)

Seagrass habitat mitigation credits generated by the proposed project will provide up-front mitigation for impacts to seagrass habitat proposed by Manatee County or other related government agencies’ projects. The attached UMAM worksheets, see Attachment B.2, provide the functional gain that may be generated by the proposed project. Since the mitigation credits will be available only after the habitat has been created and is providing function, time lag and risk factors are not applicable.

Two UMAM assessments have been provided for the assessment of seagrass habitat at the time of mitigation credit determination. One UMAM assessment applies to areas that provide patchy seagrass cover and the other UMAM assessment applies to areas providing continuous seagrass cover. Both UMAM assessments are based on cover by persistent seagrass species, including Halodule wrightii, Thalassia testudinum, and Syringodium filiforme. Although the

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UMAM relative functional gain (RFG) is not species dependent, percent species composition will be calculated and provided for future evaluation of the applicability of the seagrass mitigation credits to offset seagrass habitat impacts associated with permitted impacts.

UMAM will be utilized to calculate the quantity of Federal and state mitigation credits provided by the Seagrass Creation Area, in accordance with Chapter 62-345 of the Florida Administrative Code (FAC) and as accepted for use by the USACE. The quantity of mitigation credits will be determined by applying the UMAM RFG, as calculated on the attached UMAM worksheets and described below, to the delineated seagrass habitat polygons resulting from the monitoring activities proposed in Section 3.1.4.2.

The UMAM assessment scoring presented on the attached UMAM forms is based on the following habitat indicators. The Location and Landscape Support and Water Environment scores are the same for both patchy and continuous seagrass cover. Two scores are presented for community structure, one each for patchy cover and continuous cover.

 Location and Landscape Support

. Current

The assessment area is currently in the process of conversion from fallow farmland dominated by ruderal vegetation to an excavated freshwater pond. The area currently provides no significant ecological functions or benefits for terrestrial or aquatic species. Considering the area is upland, the current condition score is zero (0).

. With Mitigation

The seagrass creation area (assessment area) will be surrounded by complimentary habitats created along the slope of the seagrass basin. These areas will consist of a mangrove forest, naturally-recruited salt marsh, and coastal forest. The mangrove forest will increase function of the seagrass creation area as a nursery habitat. All of the habitats will function to reduce erosion from adjacent areas. The seagrass creation area as well as the adjacent habitats will be maintained to minimize or eliminate the presence of invasive plants. The flushing channels will provide regular tidal exchange and will eliminate barriers for fish and other aquatic animals to access Perico Bayou. The area beyond the seagrass creation area and adjacent slope habitats includes Phase 1 upland and wetland restoration areas on the south, west, and north. This assemblage of varied habitats provides a wildlife corridor and significant cover for wildlife accessing the seagrass creation area and adjacent habitats. The Rookery Island has been located within the central portion of the seagrass creation area to minimize the ability for predators to reach the island. The Rookery Island has been designed to provide a mangrove fringe for nesting and an interior salt barren for ground roosting and foraging.

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Given the attributes and functions detailed above, the Location and Landscape Support has a “with mitigation” score of nine (9).

 Water Environment

. Current

The assessment area is currently in the process of conversion from fallow farmland dominated by ruderal vegetation to an excavated freshwater pond. The area currently provides no water environment. Considering the area is upland, the current condition score is zero (0).

. With Mitigation

The seagrass creation area will be excavated to -2.0 feet NAVD, which corresponds to elevations within Perico Bayou that currently support healthy continuous seagrass cover. The area surrounding the Rookery Island will be excavated to -2.7 feet NAVD to provide increased protection from predators accessing the island from land during low tides. The tidal regime will provide sufficient flushing to maintain good water quality similar to Perico Bayou. As the modeling results demonstrate, the tidal regime will mimic Perico Bayou and provide optimal flushing times for seagrass establishment and growth. In addition, the modeling results demonstrate that normal flow velocities will not cause adverse erosion, sedimentation, or scouring within or adjacent to the seagrass creation area. Water quality improvements have not been modeled nor assessed; however, it is anticipated that the increased basin area and presence of submerged aquatic vegetation will provide a net water quality benefit to those portions of Perico Bayou that regularly receive tidal exchange with the seagrass creation area. The placement of oyster shell along the flushing channels will provide substrate for the attachment and colonization by mollusks and crustaceans. The presence of these water filtering organisms will provide water quality benefits, in addition to the increase forage value for fish, crabs, and other predators.

Given the attributes and functions detailed above, the Water Environment has a “with mitigation” score of nine (9).

 Community Structure

. Current

The assessment area is currently in the process of conversion from fallow farmland dominated by ruderal vegetation to an excavated freshwater pond. Considering the area is upland, the current condition score is zero (0).

. With Mitigation

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The seagrass creation area will provide a benthic community dominated by submerged aquatic vegetation (i.e. seagrass). The goal is to provide a suitable habitat for the long-term development of a climax community dominated by Thalassia testudinum. Depending on the period of time the system is allowed to mature and the method of seagrass establishment (e.g. natural recruitment or transplanting), the seagrass community throughout the seagrass creation could include patchy and/or continuous seagrass cover composed of Halodule wrightii, Syringodium filiforme, and/or Thalassia testudinum. Considering that each seagrass species provide specific habitat functions that are of similar value to the benthic environment, the specific species present within the seagrass creation area will not affect the UMAM’s community structure score.

The seagrass creation area will be constructed to have a very consistent bottom elevation throughout, with a deeper (0.7 foot) area surrounding the Rookery Island. This will allow the area to function similar to large grass flats existing in Perico Bayou and other parts of Sarasota Bay and Tampa Bay. Natural forces, such as bioturbation, will likely alter elevations in isolated areas providing a more natural bottom that will be beneficial to seagrass development.

It is anticipated, based on the proposed design, that the creation area will provide optimal seagrass habitat for the seagrass species themselves as well as fauna likely to utilize the habitat. The assemblage of invertebrate and fish species utilizing the seagrass creation area is likely to be similar to the connected and adjacent habitats of Perico Bayou, Sarasota Bay, and southern Tampa Bay.

The UMAM community structure score will be determined based on the results of the aerial assessment and quantitative monitoring, relative to the determination and mapping of patchy and continuous seagrass cover. Patchy seagrass cover will include those areas where seagrass is the dominant bottom cover (>50%) and the seagrass cover is of moderate density (25 – 50% cover per 0.5 square meter). Continuous seagrass cover will include those areas where seagrass is nearly continuous, covering more than 85% of the bottom, and the seagrass cover is dense (>50% cover per 0.5 square meter).

Areas delineated as patchy seagrass cover, as defined in Sections 3.1.4.2., will receive a community structure score of eight (8) and continuous seagrass cover will receive a community structure score of nine (9). A thorough review of research documents, leads one to conclude that there is no definitive conclusion on whether patchy seagrass is less valuable as habitat than continuous seagrass. Dense cover by continuous seagrass provides greater biomass production by unit area; however, patchy seagrass cover provides increased edge that is beneficial to predators that feed within and along seagrass beds. As is similar in terrestrial habitats, the habitat mosaic present within patchy seagrass beds may provide benefits to fauna that are not provided by continuous seagrass cover.

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However, the difference in community structure scores proposed above (eight vs. nine) is based on the potential that the patchy seagrass cover is less stable or not fully developed. This reduction in community structure accounts for seasonal variation in seagrass cover or seagrass migration that may affect the total cover by seagrass within the habitat.

3.1.4 Monitoring Details

The Applicant proposes the following monitoring methodology and success criteria for use in quantifying the mitigation credits generated by the project and available for use to compensate for habitat impacts within Manatee County proposed/approved by other governmental agencies.

3.1.4.1 Monitoring Schedule

The Applicant proposes a flexible monitoring schedule that will be dictated by the seagrass implementation method(s) utilized, rate of seagrass habitat establishment, and timeline associated with mitigation credit demand. Since this mitigation project seeks to generate mitigation credits prior to initiation of the impacts (up-front mitigation), formal monitoring to assess the credits generated will commence once the Applicant deems the seagrass creation area adequately established to warrant conducting monitoring events. However, the following requirements will be applicable once monitoring is initiated.

a) Seagrass habitat monitoring will be conducted during the active growing season, preferably June – September;

b) Annual monitoring must be conducted at least once per year during the two years prior to requesting credit determination/release; and

c) Once annual monitoring commences it must continue annually until credit determination.

3.1.4.2 Monitoring Methodology

The focus of the seagrass monitoring will be to assess the quality and quantity of seagrass habitat existing within the Seagrass Creation Area. The primary parameters requiring assessment include density, percent cover, and area. General qualitative data associated with wildlife utilization and water quality will be noted. Quantitative data will be collected to assess the quality and quantity of created seagrass habitat. The Applicant does not propose to include monitoring methodology to assess survival or expansion of any planted seagrass, if applicable, because the up-front mitigation credits are focused on the final created habitat.

The following seagrass habitat monitoring methodology is proposed to assess the Seagrass Creation Area and to obtain data required to calculate the quantity of seagrass mitigation credits generated.

I. Aerial Mapping

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Aerial photographs of sufficient quality and resolution will be collected annually for all areas within the Seagrass Creation Area. Aerial photography will be collected when weather (e.g. cloud cover and wind) and water conditions (e.g. clarity and tide height) are suitable for the collection of cloud-free images that allow the visual delineation of seagrass signatures. It is anticipated that aerial photograph resolution will be 1-foot or better. A minimum quantity, as determined by a Professional Surveyor and Mapper, of ground control points will be field-established and surveyed. Acquired aerial photography will be rectified utilizing the surveyed ground control points.

Utilizing GIS or suitable image processing/analysis software, the limits of potential seagrass and non-seagrass signatures will be delineated and overlain on the aerial photographs. Feature delineation will be accomplished through heads-up digitizing (on- screen) or supervised classification using image analysis tools. The delineated features will be converted to ESRI polygon feature classes representing seagrass and non- seagrass areas.

Quantitative transect data collected, see below, will be utilized to confirm or reject aerial signatures delineated as seagrass. For example, a patch of dark signature delineated as seagrass during the image analysis may be rejected, based on field evidence that the signature represented algae.

Following the collection and assessment of the quantitative field data, the delineated seagrass polygons will be revised. Once all areas of delineated seagrass are mapped, final seagrass polygons will be created. Seagrass polygon boundaries will be delineated based on visual continuity of seagrass and quantitative data. Polygons will be created and attributed as one of the following classifications: patchy seagrass, continuous seagrass, or non-seagrass.

The classification of seagrass areas as patchy or continuous has been debated many times without universal acceptance of a definition. SWFWMD frequently maps seagrass cover as patchy or continuous as part of its seagrass distribution mapping projects. SWFWMD does not utilize a specific percent spatial cover classification system to define patchy versus continuous seagrass; rather SWFWMD uses general references such as “continuous and uniform signature”, “small sandy bottom features may be interspersed within the bed, but are not dominant”, and “singular isolated patches of seagrass or extensive areas of patch strands”. These general definitions are useful for large-scale mapping efforts, but are not suited to smaller scale mapping and assessment like that necessary.

Handley, et.al. described a seagrass classification system in Appendix 1 of the “Seagrass Status and Trends in the Northern Gulf of Mexico: 1940-2002” report. There description was also developed for use on large-scale mapping (1:24,000) with patchy seagrass ranging from 0% (very sparse) to 85% (dense sparse). The U.S. NOAA Coastal Services Center “Guidance for Benthic Habitat Mapping: An Aerial Photographic

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Approach” publication recommends a percent cover system whereby continuous seagrass is areas where 51 – 100% of the bottom is covered by SAV and patchy is all areas where up to 50% of the bottom is covered by SAV.

Considering that this project is relying on small-scale seagrass habitat mapping (approximately 1:1,200) and the goal is to provide seagrass habitat providing fishery and other habitat function, the patchy/continuous seagrass definition will be based on the structure of the seagrass habitat necessary to provide ecological functions being assessed. Therefore, patchy seagrass is defined as areas with spatial cover between 51% and 85%. This spatial cover percent defines patchy seagrass areas as being dominated by seagrass cover. Continuous seagrass cover is defined as areas with spatial cover greater than 85%.

Polygons will be created and classified as continuous seagrass for areas containing seagrass that are larger than 435 square feet with less than 15 percent bare (non- seagrass) sediment based on aerial signatures. Polygons will be created and classified as patchy seagrass for areas containing multiple seagrass patches, each less than 435 square feet, that collectively cover a minimum of 435 square feet and contain between 15 and 50 percent bare (non-seagrass) sediment based on aerial signatures.

The anticipated minimum feature size is 400 square feet, but may be adjusted depending on the quality of aerial photography during the first monitoring event. The minimal detectable unit is estimated to be four (4) square feet, but will be determined upon review of aerial photography during the first monitoring event.

II. Quantitative Monitoring

Quantitative seagrass habitat monitoring data will be collected during each monitoring event using the point-intercept method. The collected data will be utilized to calculate seagrass abundance, species abundance, density, and estimated percent cover. Prior to the first monitoring event, a point-grid overlay will be created for the entire Seagrass Creation Area using GIS. The point overlay will consist of points spaced 30 meters apart throughout the creation area.

Prior to each monitoring event, the delineated seagrass polygons from the aerial assessment will be overlain on the point-grid and those points falling within the delineated polygons will be selected as potential point intercept sampling locations. A random subset of the selected points will be selected as the point intercept sampling locations. In addition, each point will have a randomly chosen bearing that will be used as the bearing for orienting the transect. Any transects that will fall outside of the delineated polygons will be recalculated such that all sampling occurs within delineated seagrass polygons.

During each monitoring event the following monitoring procedures will be followed:

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1) Using a sub-meter DGPS or better, sampler will navigate to each point intercept sample point and extend a 25-meter transect line in the direction of the previously chosen bearing direction.

2) Starting at zero (0) meter, a qualified ecologist will swim the entire transect with a one-meter rod centered along the transect line. The ecologist will note the distance along the transect line where any seagrass or algal species are encountered within the one-meter belt. Distance measures will be species specific (i.e. where shoalgrass transitions to turtlegrass the distance for shoalgrass will end when the distance for turtlegrass begins) to avoid inflating the distance covered by seagrass.

3) In addition to the belt transect distance-occurrence measurements, a 0.5 meter by 0.5 meter (quarter-meter square) quadrat divided into 100 cells will be centered on the transect and sampled at 0, 5, 10, 15, 20, and 25 meters along the transect line.

4) At each quadrat location, the following quantitative data will be collected:

 Braun-Blanquet Cover Abundance (BBCA) score for all seagrass species;

 BBCA score for each identified seagrass species; and

 BBCA score for algae;

5) BBCA scores will collected based on the following values:

 0 = no seagrass present

 0.1 = solitary shoots with small cover

 0.5 = few shoots with small cover

 1.0 = numerous shoots but less than 5% cover

 2.0 = any number of shoots but with 5-25% cover

 3.0 = any number of shoots but with 25-50% cover

 4.0 = any number of shoots but with 50-75% cover

 5.0 = any number of shoots but with > 75% cover

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6) At each quadrat location, any observations of epiphytic cover, fauna utilization, bioturbation, or other conditions that may positively or negatively affect seagrass cover or function.

7) Representative photographs will be taken along transects and at random quadrat locations.

3.1.4.3 Monitoring Assessment and Reporting

A monitoring report will be provided to both SWFWMD and USACE within 60 days following the completion of each monitoring event. Quantitative data collected during each monitoring event will be utilized to calculate species abundance, seagrass density, and percent cover. Qualitative data acquired as observations during the monitoring event will be summarized within the report.

The monitoring report will contain, at a minimum, the following items:

a) Project Overview including project description and activities completed,

b) Description of monitoring methodology,

c) Results from quantitative and qualitative monitoring,

d) Maps showing delineated seagrass polygons and monitoring transects,

e) Discussion of monitoring and aerial assessment results,

f) A statement regarding potential seagrass habitat mitigation credits achieved based on application of UMAM RFG to quantified acreages of patchy and/or continuous seagrass cover, and

g) Appendices containing collected quantitative data, aerial photograph maps with ground control points, and representative photographs.

3.1.5 Mitigation Credit Determination

3.1.5.1 Quantification Methodology

Seagrass mitigation credits available for release will be quantified by applying the appropriate UMAM-calculated RFG (patchy or continuous) to the delineated seagrass polygons, as described in Section 3.1.3 Mitigation Credit Assessment above. Patchy and continuous seagrass cover are defined in Section 3.1.4.2 above. Credit criteria for each seagrass cover type (patchy or continuous) are described below.

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The UMAM RFG for patchy seagrass will be applied to delineated seagrass polygons where the following criteria are met: a) Minimum polygon size of 435 square feet, b) 51 to 85 percent spatial seagrass cover based on aerial signature, and c) A minimum average Braun-Blanquet Cover Abundance score of 3, representing moderate seagrass density. The UMAM RFG for continuous seagrass will be applied to delineated seagrass polygons where the following criteria are met: a) Minimum polygon size of 435 square feet, b) Greater than 85 percent spatial seagrass cover based on aerial signature, and c) A minimum average Braun-Blanquet Cover Abundance score of 4, representing dense seagrass density. Final credit determination will be based on the mean functional gain (approved credits) attained during the two years with the highest documented functional gain. Please see example credit determination below.

Credit Determination Example Annual Acreage UMAM Credit Cover By UMAM Final Credits Year FG/ Sum Type Cover RFG (two year mean) Credits (highest Type bold) 2014 Patchy 5.73 0.87 4.99 8.72 2014 Continuous 4.15 0.90 3.74 2015 Patchy 2.10 0.87 1.83 9.94 2015 Continuous 9.01 0.90 8.11 10.09 2016 Patchy 2.80 0.87 2.44 9.50 2016 Continuous 7.85 0.90 7.07 2017 Patchy 3.07 0.87 2.67 10.25 2017 Continuous 8.42 0.90 7.58

Those areas within the Seagrass Creation Area that were not delineated as patchy or continuous seagrass during the two years averaged to calculate the “approved credits”, will remain eligible to generate mitigation credits and be classified as unvegetated bottom.

3.1.5.2 Schedule and Release Details

Seagrass habitat mitigation credits will be quantified at a point in time dictated by the Applicant. Seagrass mitigation credits will not be available until the Applicant has submitted and received

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written approval of a formal credit determination request to SWFWMD and USACE. The formal credit request shall be submitted following or simultaneously with the annual monitoring report for that year. Both the monitoring report and credit request shall be submitted early enough in the growing season (i.e. prior to September 15) to allow sufficient time for field inspection by SWFWMD and USACE staff, if requested.

Mitigation credits will become available for use by other governmental agencies following the approval of the formal credit determination request, execution and recording of a conservation easement, and the preparation of a mitigation credit ledger for SWFWMD and USACE.

Applicant may continue to monitor the unvegetated bottom areas and submit a new formal credit determination request to SWFWMD and USACE once these areas meet the mitigation credit criteria. All future requests must adhere to the monitoring methodology and credit determination criteria detailed above.

Applicant acknowledges that each agency proposing to utilize mitigation credits generated by the Rookery at Perico Seagrass Advance Mitigation project must demonstrate, independently, that the Rookery at Perico mitigation credits sufficiently offset the impacts proposed by the agency’s project.

3.1.6 Long-Term Protection

The Applicant will execute a conservation easement over the Seagrass Creation Area. Motorized vessels will be restricted from the area and the Applicant will post signage and take other appropriate measures to minimize or eliminate foot traffic through the creation area. If necessary, Applicant will maintain flushing channels in a condition that allows sufficient flushing of the Seagrass Creation Area.

3.2 MANGROVE HABITAT CREATION

Mangrove forest will be created along the slope surrounding the Seagrass Creation Area. The purpose of the mangrove habitat creation is to provide a reserve of mitigation credits that other governmental agencies within Manatee County can draw upon to offset mangrove impacts associated with their projects.

3.2.1 Design Details

As described in Section 2.1 above, a 0.5 acre mangrove mitigation area will be constructed along the southern slope of the Seagrass Creation Area. Outside of the mangrove mitigation area along the seagrass basin slope, a 1.27 acre natural recruitment zone is proposed from elevation -1.5 feet NAVD to 1.0 foot NAVD. An additional 0.11 acre mangrove creation area (Rookery Island Planting Zone) will be constructed around the perimeter shelf of the Rookery Island at elevation of 0.20 feet NAVD. Please reference Construction Plans showing the proposed location and elevation of the natural recruitment zone and Rookery Island Planting Zone. The Applicant will allow mangroves and/or saltmarsh habitat to naturally recruit within the

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natural recruitment zone; however, the Applicant may also encourage the establishment of a mangrove forest through the installation of mangrove propagules or container-grown mangroves. The Rookery Island Planting Zone will be planted with 45 container-grown (minimum 1 gallon) red mangroves.

3.2.2 Mitigation Credit Assessment (UMAM)

Mangrove habitat mitigation credits generated by the proposed project will provide up-front mitigation for impacts to mangrove habitat proposed by Manatee County or other related government agencies’ projects. The attached UMAM worksheets, see Attachment B.2, provide the functional gain generated by the proposed project. Since the mitigation credits will be useable only when the habitat has been created and is providing function, time lag and risk factors are not applicable.

UMAM will be utilized to calculate the quantity of Federal and state mitigation credits provided by the mangrove creation areas, in accordance with Chapter 62-345 of the Florida Administrative Code (FAC) and as accepted for use by the USACE. The quantity of mitigation credits will be determined by applying the UMAM RFG, as calculated on the attached UMAM worksheets and described below, to the delineated mangrove habitat polygons resulting from the monitoring activities proposed in Section 3.2.3.2. The UMAM assessment scoring presented on the attached UMAM forms is based on the following habitat indicators.

 Location and Landscape Support

. Current

The assessment area is currently in the process of conversion from fallow farmland dominated by ruderal vegetation to an excavated freshwater pond bank. The area currently provides no significant ecological functions or benefits for terrestrial or aquatic species. Considering the area is upland, the current condition score is zero (0).

. With Mitigation

The mangrove creation areas (natural recruitment zone and Rookery Island planting zone) will surround the seagrass basin and Rookery Island. The mangrove area will provide a forested fringe between the seagrass basin and the restored upland habitats. Nuisance, exotic, and invasive plant species will be controlled through maintenance events to maintain cover of these species at less than five percent (5%). The mangrove area will provide nursery habitat suitable for foraging and shelter by many species of fish and crustaceans. Prop roots of red mangroves will provide suitable surfaces for adherence by clams, oysters, barnacles, and similar organisms. The mangrove forest will provide nesting and roosting habitat for a variety of wading birds, including little blue herons (Egretta caerulea), great blue herons (Ardea herodius), and great egrets (Ardea albus). In addition, the seagrass

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basin slope mangrove forest will provide cover for mammals to move throughout Perico Preserve. The isolation of the Rookery Island from the surrounding uplands will decrease the potential for predators to have access to bird nests. The unvegetated central portion of the Rookery Island will provide a protected area for mating and newly fledged birds to learn forage behavior.

Given the attributes and functions detailed above, the Location and Landscape Support has a “with mitigation” score of eight (8).

 Water Environment

. Current

The assessment area is currently in the process of conversion from fallow farmland dominated by ruderal vegetation to an excavated freshwater pond. The area currently provides no water environment. Considering the area is upland, the current condition score is zero (0).

. With Mitigation

The elevations at which the mangrove creation areas will be established correspond to mean high water and elevations of existing mangroves. The tidal connections will allow the hydrologic regime within the tidal basin to mimic Perico Bayou, thus providing adequate hydrology and water quality. The area surrounding the Rookery Island will be excavated to -2.7 feet NAVD to provide increased protection from predators accessing the island from land during low tides. The tidal regime will provide sufficient flushing to maintain good water quality that is similar to Perico Bayou.

Given the attributes and functions detailed above, the Water Environment has a “with mitigation” score of eight (8).

 Community Structure

. Current

. With Mitigation

The mangrove creation areas will be vegetated with mangroves through a combination of natural recruitment and planting. Nuisance, exotic, and invasive plant

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species will be controlled through maintenance events to maintain cover of these species at less than five percent (5%).

Given the attributes and functions detailed above, the Community Structure has a “with mitigation” score of eight (8).

3.2.3 Monitoring Details

3.2.3.1 Monitoring Schedule

The Applicant proposes a flexible monitoring schedule that will be dictated by the mangrove implementation method(s) utilized, rate of mangrove canopy establishment, and timeline associated with mitigation credit demand. Since this mitigation project seeks to generate mitigation credits prior to initiation of the impacts (up-front mitigation), formal monitoring to assess the credits generated will commence once the Applicant deems the mangrove creation areas adequately established to warrant conducting monitoring events. However, the following requirements will be applicable once monitoring is initiated.

a) Annual monitoring must be conducted at least once per year during the three years prior to requesting credit determination/release and

b) Once annual monitoring commences it must continue annually until credit determination.

3.2.3.2 Monitoring Methodology

The mangrove creation areas will be monitored following the same methodology proposed for the Seagrass Mitigation Area, as described in Section 2.2 and detailed below.

The monitoring will be conducted by a qualified professional. The mangrove monitoring will consist of a qualitative assessment and quantitative assessment, as detailed below. A report summarizing the conditions observed during the monitoring event and a discussion relating observed conditions to the mitigation credit determination will be prepared.

The qualitative assessment will include a visual inspection of the mangrove creation areas to note general observations of reduced/exceptional mangrove growth, estimated nuisance/invasive species cover, areas of erosion, and fauna utilization.

The quantitative assessment will provide data suitable for estimating areal percent cover by mangroves, areal percent cover by nuisance/exotic species, and annual growth rate. Quantitative monitoring will be conducted using line intercept transects in randomly selected locations within the mangrove creation areas. Detailed monitoring procedures are as follows:

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1. The MHW line will be utilized as a linear baseline through the area and will be stationed in 10-foot sections starting at zero at the southernmost or westernmost edge. The outside top-of-bank will be utilized as the linear baseline on the Rookery Island.

2. Using GIS, a minimum of one (1) transect per 75 feet linear feet of mangrove covers will be generated at random 10-foot stations oriented perpendicular to the baseline.

3. Each monitoring transect will be located in the field and the start and end points will be marked at the terminus of mangrove canopy cover.

4. A measuring tape will be extended between the markers with the zero point on the waterward end of the transect.

5. Starting at zero, the species and height of the nearest mangrove individual to the line will be collected every 0.5 meter. This data will be used to calculate the average height of the mangroves (by species) and annual growth rate.

A monitoring report will be provided to both SWFWMD and USACE within 60 days following the completion of each monitoring event. Quantitative data collected during each monitoring event will be utilized to calculate species abundance, average mangrove height, annual growth rate, and percent cover. Qualitative data acquired as observations during the monitoring event will be summarized within the report.

The monitoring report will contain, at a minimum, the following items:

h) Project Overview including project description and activities completed,

i) Description of monitoring methodology,

j) Results from quantitative and qualitative monitoring,

k) Maps showing created mangrove habitat limits and monitoring transects,

l) Discussion of monitoring results,

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m) A statement regarding potential mangrove habitat mitigation credits achieved based on application of UMAM RFG to quantified acreages meeting the credit determination criteria, and

n) Appendices containing collected quantitative data and representative photographs.

3.2.4 Mitigation Credit Determination

3.2.4.1 Quantification Methodology

At the time the Applicant desires to submit a mangrove habitat mitigation credit determination request, a sub-meter DGPS shall be utilized to collect points denoting the limits of the created mangrove habitats meeting the mitigation credit criteria. Points collected shall be spaced a maximum of 30 feet apart and shall adequately capture the limits of the zone. Mangrove habitat mitigation credits available for release will be quantified by applying the UMAM-calculated RFG to the acreage based on the delineated limits.

Only those mangrove habitat areas meeting the mitigation credit determination criteria below will be included in the delineated mangrove habitats.

a) The created mangrove habitat meets the definition of a mangrove swamp (FLUCCS:612) through dominance of mangrove species;

b) The created mangrove habitat can be determined to be a wetland or other surface water pursuant to Chapter 62-340, F.A.C.;

c) Estimated areal percent cover by mangrove species for each delineated mangrove habitat area is 60 percent or greater;

d) A positive annual growth rate over a period of three years (minimum) is documented;

e) The calculated average mangrove height is four (4) feet or greater; and

f) Cover by nuisance and invasive species is less than 5 percent.

3.2.4.2 Schedule and Release Details

Mangrove habitat mitigation credits will be quantified at a point in time dictated by the Applicant. Mangrove mitigation credits will not be available until the Applicant has submitted and received written approval of a formal credit determination request to SWFWMD and USACE. The formal credit request shall be submitted following or simultaneously with the annual monitoring report for that year.

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Applicant may continue to monitor the mangrove habitat creation areas that were not a subject of the credit release and submit a new formal credit determination request to SWFWMD and USACE once these areas meet the mitigation credit criteria. All future requests must adhere to the monitoring methodology and credit determination criteria detailed above.

3.2.5 Mangrove Creation Areas Long-Term Protection

The mangrove creation areas will be maintained in perpetuity following determination of mitigation credits. An appropriate maintenance schedule will be developed to minimize the presence of nuisance/invasive species through the application of approved, systemic herbicides and/or hand removal. The maintenance schedule will minimize the application of herbicides through active monitoring, allowing maintenance events to be completed when necessary. In addition to the control of nuisance/invasive species, the Applicant will implement practices to keep the mangrove creation areas free from human disturbance or destruction to the greatest extent practical.

The creation area will be maintained at the credit determination criteria by the Applicant in perpetuity. In addition, the area will be included within the conservation easement boundary.

4.0 Bibliography

Fonseca, Mark S., et al. 1998. Guidelines for the Conservation and Restoration of Seagrasses in the United States and Adjacent Waters. NOAA Coastal Ocean Program Decision Analysis Series No. 12. NOAA Coastal Ocean Office, Silver Spring, MD. 222 pp.

Handley, L., et.al., eds., 2007, Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002: U.S. Geological Survey Scientific Investigations Report 2006–5287, 267 pp.

Montin, Gary J. & Dennis III, Raymond F., A Shallow Water Technique for the Successful Relocation and/or Transplantation of Large Areas of Shoalgrass (Halodule wrightii) (Env. Affairs Consultants, Inc. Oct. 2003) (published in the Proceedings of the Hillsborough Community College 30th Annual Conf.: Ecosystems Restoration and Creation).

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U.S. NOAA Coastal Services Center. 2001. Guidance for Benthic Habitat Mapping: An Aerial Photographic Approach by Mark Finkbeiner [and by] Bill Stevenson and Renee Seaman, Technology Planning and Management Corporation, Charleston, SC. (NOAA/CSC/20117-PUB).

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Appendix A Figures

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A.1 SEAGRASS DONOR AREA EXHIBIT

rh \\us1227-f01\workgroup\2155\active\215510428\env\05_rpt-deliv\deliverables\swfwmd\submittal_final\rpt_mitigation_credits_20130516_final.docx A.1 Note: Donor material will be harvested within this area where seagrass cover is assessed as a minimum of "4" on the Braun-Blanquet Cover Abundance scale only. 1:05:01 PM

LEGEND Seagrass Donor Area Project Boundary Property Boundary

Feet Stantec Consulting Services Inc. 0 150 300 2205 North 20th Street Rookery at Perico Seagrass Advance Mitigation The information on this map has been compiled Tampa, FL 33605 by Stantec staff from a variety of sources and is SEAGRASS DONOR AREA subject to change without notice. Stantec makes tel 813.223.9500 no representations or warranties, express or implied, MAY 2013 as to accuracy, completeness,timeliness, or rights fax 813.223.0009 to the use of such information. ³ \\us1227-f01\workgroup\2155\active\215510428\gis\mxd\SWFWMD_Initial\215510428_donor_area_89523_20130430.mxd | Saved: 5/3/2013 One Team. Infinite Solutions. ROOKERY AT PERICO SEAGRASS ADVANCE MITIGATION Appendix B Attachments May 17, 2013

Appendix B ATTACHMENTS

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B.1 PERICO PRESERVE HABITAT RESTORATION MODELING STUDY PREPARED BY COASTAL PLANNING AND ENGINEERING, INC. DECEMBER 2012

rh \\us1227-f01\workgroup\2155\active\215510428\env\05_rpt-deliv\deliverables\swfwmd\submittal_final\rpt_mitigation_credits_20130516_final.docx B.1 PERICO PRESERVE HABITAT RESTORATION MODELING STUDY MANATEE COUNTY, FL

Prepared for:

Manatee County, Florida

Prepared by:

Coastal Planning & Engineering, Inc., 2481 N.W. Boca Raton Blvd. Boca Raton, FL 33431

December 2012 PERICO PRESERVE HABITAT RESTORATION MODELING STUDY MANATEE COUNTY, FL

EXECUTIVE SUMMARY

Perico Preserve Restoration area is located on Perico Island in Manatee County between Tampa Bay and Sarasota Bay, east of Anna Maria Island. The project area is former farmland located on Perico Island that Manatee County purchased and plans to restore as seagrass and mangrove habitat designed by WilsonMiller Stantec Inc. (Stantec). The restoration will include channels from Perico Bayou to the restoration site and a canal that utilizes pre-existing mosquito control ditches to connect to Spoonbill Bay.

This report presents a tidal exchange analysis of the preliminary design and the most recent design through numerical modeling to evaluate circulation and residence (flushing) time. The flushing of the created subtidal and intertidal habitats is dependent on the connections to Tampa Bay and Sarasota Bay through adjacent water bodies – Perico Bayou to the east and Spoonbill Bay to the south. Based on the model results:

 The major effects of the project on flow during average conditions would be limited to the immediate project area. Outside the immediate project area, project-induced changes in currents would be small (~0.3 feet/second) or negligible.

 Overall, the main conduits for the flushing of the Habitat Restoration’s main pond will be the two cuts connecting it to Perico Bayou.

 Given the release of a pollutant inside the project’s main pond only, the times required to dilute the pollutant to 10% and 1% of its initial concentration in the immediate project area would be 2 to 3 days and 7 to 8 days, respectively. Most of the flushing would occur through the two cuts connecting the main pond to Perico Bayou. As such, a clog in the mosquito ditch that connects the pond to Spoonbill Bay would not have a significant impact on flushing times. The amount of time required to flush the pollutant out of Perico Bayou and Palma Sola Bay as a whole would be on the order of 9 to 11 days.

 Under the existing conditions, roughly 6 to 8 days would be required to dilute a pollutant released inside Perico Bayou and Spoonbill Bay to 10% of its original concentration in those two water bodies.

 Under the with-project conditions, roughly to 6 to 9 days would be required to dilute a pollutant released inside Perico Bayou, Spoonbill Bay, and the project’s main pond to 10% of its original concentration in those areas. A clog in the mosquito ditch connecting the pond to Spoonbill Bay would not have a significant impact on those flushing times.

 Based on the sediment analysis of local grain size and simulated current speeds, the flushing channels will be stable. Additionally, the current speeds within the remainder of the model are below the threshold for sediment mobility.

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PERICO PRESERVE HABITAT RESTORATION MODELING STUDY MANATEE COUNTY, FL

Table of Contents

1. INTRODUCTION ...... 1 1.1 Methodology ...... 1 1.2 Project Area ...... 1 2. MODELING DATA ...... 2 2.1 Bathymetry and Topography ...... 2 2.2 Water Levels ...... 6 2.3 Weather Data ...... 9 2.4 Seagrass ...... 9 2.5 Forest Locations ...... 9 3. MODEL GRIDS ...... 9 4. MODEL CALIBRATION ...... 17 4.1 Model Forcing ...... 17 4.2 Calibration Parameters ...... 17 4.3 Culvert ...... 23 4.4 Initial Calibration Results ...... 23 4.5 Sensitivity Analysis and Model Refinement ...... 23 4.6 Final Calibration Results ...... 26 5. REGIONAL MODEL SIMULATIONS ...... 33 5.1 Water Levels ...... 33 5.2 Winds ...... 35 5.3 Rainfall ...... 35 5.4 Bottom Friction ...... 35 5.5 Regional Model Results ...... 35 6. LOCAL MODEL SIMULATIONS GIVEN THE PROPOSED ALTERNATIVES ...... 40 6.1 Alternative 1: No-Action Scenario ...... 41 6.2 Alternative 2: April-September 2012 Design ...... 42 6.3 Alternative 3: October 2012 Design...... 43 6.4 Alternative 4: October 2012 Design with Clogged Mosquito Ditch ...... 44 6.5 Sediment Mobility ...... 45 7. CONCLUSIONS ...... 68 8. REFERENCES ...... 69

List of Figures

Figure 1: Perico Preserve Location (Stantec, 2012)...... 2 Figure 2: Project Features Based on the Stantec April-September 2012 Design...... 3 Figure 3: Tide Gage Locations...... 7 Figure 4: June 2012 Water Level Measurements by CPE and USGS...... 8 Figure 5: Observed Water Levels and Astronomical Tides at ANMF1 during the June 2012 Deployment Period...... 8 Figure 6: Observed and Simulated Water Levels during Average Conditions...... 10 ii COASTAL PLANNING & ENGINEERING, INC.

Figure 7: Seagrass and Forest Locations near the Project Area...... 11 Figure 8: Typical Condition of the Existing Mosquito Ditches...... 12 Figure 9: Local Flow Grid...... 13 Figure 10: Calibration Grid and Local Flow Grid near Culvert under Manatee Avenue...... 14 Figure 11: Regional Flow Grid...... 15 Figure 12: Regional Flow Grid Bathymetry...... 16 Figure 13: Local Flow Grid Bathymetry and Topography...... 18 Figure 14: Local Flow Grid Bathymetry and Topography near the Project Area...... 19 Figure 15: Wind Velocities at ANMF1 during the Calibration Period...... 20 Figure 16: Rainfall during the Calibration Period...... 21 Figure 17: Typical Bottom Friction Map during the Initial Calibration Phase...... 22 Figure 18: Simulated and Observed during the Initial Calibration Phase...... 23 Figure 19: February 3, 2012 Photograph of Culvert under Manatee Avenue...... 25 Figure 20: Close-up of Local Flow Grid Bathymetry near Culvert under Manatee Avenue...... 25 Figure 21: Bottom Friction Map Used in the Final Calibration Run and Subsequent Model Runs...... 27 Figure 22: Wind and Rainfall Sensitivity Analysis Results...... 28 Figure 23: Typical Simulated Currents during the Calibration Period...... 29 Figure 24: Typical Simulated Water Levels during the Calibration Period...... 30 Figure 25: Simulated Currents and Water Levels in the Culvert Interior, Final Calibration...... 31 Figure 26: Simulated Currents under the Manatee Avenue Bridge, Final Calibration...... 32 Figure 27: Average Condition Water Levels...... 34 Figure 28: Bottom Friction Map Used in the Regional Model...... 36 Figure 29: Typical Simulated Currents over the Regional Flow Grid...... 37 Figure 30: Typical Simulated Water Levels over the Regional Flow Grid...... 38 Figure 31: Comparison of Open-Gulf Water Levels to Water Levels on the Open Boundaries of the Local Flow Grid...... 39 Figure 32: Bottom Friction Map for Alternative 2...... 46 Figure 33: Alternative 3 Design Changes...... 47 Figure 34: Bottom Friction Map for Alternative 3...... 48 Figure 35: Alternative 4 Clogged Bathymetry...... 49 Figure 36: Initial Tracer Location (Dark Red) for Scenario A, Alternatives 2, 3, and 4...... 50 Figure 37: Concentration Tracking Points & Initial Tracer Location (Dark Red) for Scenario B, Alternatives 1, 3, and 4...... 51 Figure 38: Typical Spring-Tide Flood Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 2...... 52 Figure 39: Typical Spring-Tide Ebb Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 2...... 53 Figure 40: Simulated Currents in the Culvert Interior under Average Conditions Given Alternatives 1 and 2...... 54 Figure 41: Simulated Currents outside the South End of the Culvert under Average Conditions Given Alternatives 1 and 2...... 55 Figure 42: Simulated Currents under the Manatee Avenue Bridge under Average Conditions Given Alternatives 1 and 2...... 56 Figure 43: Increases (+greens) or Decreases (-reds) in Current Speed Given the Construction of Alternative 2...... 59 iii COASTAL PLANNING & ENGINEERING, INC.

Figure 44: Typical Spring-Tide Flood Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 3...... 60 Figure 45: Typical Spring-Tide Ebb Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 3...... 61 Figure 46: Increases (+greens) or Decreases (-reds) in Current Speed Given the Construction of Alternative 3...... 62 Figure 47: Simulated Currents in the Culvert Interior under Average Conditions Given Alternatives 1 and 3...... 63 Figure 48: Simulated Currents outside the South End of the Culvert under Average Conditions Given Alternatives 1 and 3...... 64 Figure 49: Simulated Currents under the Manatee Avenue Bridge under Average Conditions Given Alternatives 1 and 3...... 65 Figure 50: Simulated Currents within the Mosquito Ditch and Flushing Channels under Average Conditions Given Alternative 3 as Compared to the Critical Velocity for Sediment Mobility. ... 66 Figure 51: Simulated Currents within the Culvert Interior under Average Conditions as Compared to the Critical Velocity for Sediment Mobility...... 67

List of Tables

Table 1: Bathymetric and Topographic Data Sources ...... 5 Table 2: Tide Gage Locations ...... 6 Table 3: Delft3D Grid Characteristics ...... 13 Table 4: Perico Preserve Delft3D-FLOW Calibration Summary ...... 21 Table 5: Summary of Wind and Rainfall Sensitivity Analysis ...... 26 Table 6: Delft3D Calibration Parameters, Perico Preserve ...... 33 Table 7: Bottom Roughness Coefficients for Alternatives 2 through 4 ...... 42 Table 8: Perico Bayou Tidal Flushing Results, Scenario B, Tracer in Spoonbill Bay, Perico Bayou, & Rookery ...... 57 Table 9: Perico Bayou Tidal Flushing Results, Scenario A, Tracer in Rookery Only ...... 58

List of Appendices

Appendix A: Current, Water Level, and Tracer Animations in *.WMV format only. Appendix B: Tidal Flushing Estimates. Appendix C: Granularmetric Analysis

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PERICO PRESERVE HABITAT RESTORATION MODELING STUDY MANATEE COUNTY, FL

1. INTRODUCTION

The Perico Preserve Habitat Restoration area is located on the Perico Island in Bradenton, Manatee County, FL on the east side of Sarasota Bay across from the north end of Anna Maria Island (Figure 1). The project area is former farmland that Manatee County purchased and plans to restore as seagrass and mangrove habitat designed by WilsonMiller Stantec Inc. (Stantec). The restoration will include channels from Perico Bayou to the restoration site and a canal that utilizes preexisting mosquito control ditches to connect to a box culvert that goes under Manatee Avenue into Spoonbill Bay.

The restoration will create intertidal and subtidal zones with seagrass and mangrove habitat in Sarasota Bay and lower Tampa Bay. The project aims to allow sustaining suitable habitat conditions.

This study was performed by Coastal Planning & Engineering, Inc. (CPE) and provides a numerical modeling analysis of the Perico Preserve Habitat Restoration project to assess circulation and residence (flushing) time of the restoration area in support of the County’s permit application.

1.1 Methodology

This report presents a tidal exchange analysis of the restoration area through the development and numerical modeling of alternatives to evaluate options for the created habitat. For model development, existing datasets were supplemented with bathymetric and topographic surveys by Stantec, water level measurements, sediment samples, and ground-level photography. The alternatives were analyzed using the Delft3D-FLOW model (Deltares, 2011) in depth-averaged mode to assess the circulation and residence (flushing) time of each option. Delft3D-FLOW is a multi-dimensional (2D or 3D) hydrodynamic simulation program capable of calculating non- steady flow resulting from tidal and meteorological forcing on a boundary fitted grid (Deltares, 2011).

1.2 Project Area

The Perico Preserve Habitat Restoration area is located on Perico Island, which is bordered by Perico Bayou, Anna Maria Sound, and Palma Sola Bay (see Figure 1). The island is occupied by residential housing developments, mangrove swamp, and vacant farmland that will be converted into the Perico Preserve. The project area itself is located north of the Perico Island housing development on the eastern side of the island.

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Figure 1: Perico Preserve Location (Stantec, 2012).

A more detailed view of the project area appears in Figure 2. The project will have three primary design features – a large, saltwater pond with a Rookery Island in the middle and seagrass on the bottom, flushing cuts on the eastern side of the pond, and a restored and extended mosquito ditch connecting the main pond to an existing culvert under Manatee Avenue. Additional design features include a number of smaller ponds outside the main pond and two mound features on the southern and eastern sides of the main pond.

2. MODELING DATA

2.1 Bathymetry and Topography

The primary sources of topographic and bathymetric data used in this study were the following:

1. Topographic survey points appearing on the September 2012 survey drawing by Stantec.

2. Topographic survey points appearing on the April 2012 project plans by Stantec.

3. The July 2007 Light Detection and Ranging (LIDAR) survey by the Florida Division of Emergency Management (FDEM). This survey was distributed in ASCII grid format by the NOAA Digital Coast website (http://www.csc.noaa.gov/digitalcoast/data). The spacing of the ASCII grid files was 5 feet.

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CUTS CUTS TIDAL FLUSHING FLUSHING DITCH OF MOSQUITO OF MOSQUITO RESTORATION RESTORATION AND EXTENSION SEAGRASS SEAGRASS PROPOSED POND WITH SALTWATER SALTWATER EXISTING CULVERT CULVERT

Figure 2: Project Features Based on the Stantec April-September 2012 Design.

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4. Digital Elevation Models (DEMs) by the U.S. Geological Survey (USGS, 2004). The DEM files were distributed by http://data.geocomm.com/ and had a spacing of 33 feet (10 meters). The DEMs were published in 2004, but were based on quad maps that reflect 1984 conditions.

5. The 1953 and 1954 surveys of Sarasota Bay, Anna Maria Sound, and Tampa Bay by the National Oceanographic and Atmospheric Administration (NOAA).

Regional model simulations, which are discussed later in this report, used the following additional data sources:

1. The October 2011 survey of Longboat Key by Coastal Planning & Engineering, Inc. (CPE, 2012).

2. The June 2011 survey of Lido Beach, Sarasota by CPE (2011).

3. The May 2011 surveys of Anna Maria Island and Longboat Pass by CPE (2011).

4. The November 2010 survey of Longboat Pass by the U.S. Army Corps of Engineers.

5. The August 2010 survey of southern Siesta Key by CPE (2010).

6. The June-July 2010 LIDAR survey of the region’s coastline by the Joint Airborne LIDAR Bathymetry Technical Center of Expertise (JALBTCX). This survey was distributed in ASCII grid format by the NOAA Digital Coast website (http://www.csc.noaa.gov/digitalcoast/data). The spacing of the ASCII grid files was 6 feet.

6. The January 2010 survey of New Pass by the U.S. Army Corps of Engineers.

7. The October 2009 survey of Anna Maria Island by CPE (2010).

8. The July-September 2005 survey of Siesta Key by FDEP (2005).

9. The Tampa Bay DEM by USGS (2001).

10. The U.S. Coastal Relief Model by NOAA (2006) available under the “Design-a-Grid” website (http://www.ngdc.noaa.gov/mgg/gdas/gd_designagrid.html).

The datums and accuracy of each data source appear in Table 1. The primary datums used in the model study were the Florida State Plane Coordinate System, West Zone, North American Datum of 1983 (FL-West NAD83) and the North American Vertical Datum of 1988 (NAVD). Conversions to these datums were performed using the following:

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Table 1: Bathymetric and Topographic Data Sources

Vertical Horizontal Datum and Vertical Accuracy Areas Date Source Datum and Units (approx.) Units Stantec September 2012 Perico Preserve Project Area Summer 2012 FL-West NAD83 feet feet NAVD 0.2 feet Survey Drawing Stantec April 2012 Perico Preserve Project Area Spring 2012 FL-West NAD83 feet feet NAVD 0.2 feet Project Plans 0.16 feet onshore Longboat Key October 2011 CPE (2012) FL-West NAD83 feet feet NAVD 0.5 feet offshore 0.16 feet onshore Lido Beach, Sarasota June 2011 CPE (2011) FL-West NAD83 feet feet NAVD 0.5 feet offshore Anna Maria Island and 0.16 feet onshore May 2011 CPE (2011) FL-West NAD83 feet feet NAVD Longboat Pass 0.5 feet offshore Longboat Pass November 2010 USACE (2010) FL-West NAD83 feet feet MLLW 0.5 feet Southern Siesta Key 0.16 feet onshore August 2010 CPE (2010) FL-West NAD83 feet feet NAVD (Point O’ Rocks to Midnight Pass) 0.5 feet offshore Collier County June-July 2010 JALBTCX / NOAA LIDAR FL-West NAD83 feet feet NAVD 0.5 feet to Pasco County New Pass January 2010 USACE (2010) FL-West NAD83 feet feet MLLW 0.5 feet 0.16 feet onshore Anna Maria Island October 2009 CPE (2010) FL-West NAD83 feet feet NAVD 0.5 feet offshore Collier County July-Aug. 2007 FDEM / NOAA LIDAR FL-West NAD83 feet feet NAVD 0.5 feet to Pinellas County July-September 0.16 feet onshore Sarasota County FDEP (2005) FL-West NAD83 feet feet NAVD 2005 0.5 feet offshore NAD83 Latitude & Tampa Bay 1945-1996 USGS (2001) feet NAVD 0.5 feet Longitude Manatee County 1984 USGS DEMs UTM-17N NAD83 m m NGVD 0.5 feet Sarasota Bay, Anna Maria NOAA Surveys NAD83 Latitude & 1953-1954 m MLW 0.5 feet Sound, and Tampa Bay H08034 and H08035 Longitude U.S. Coastal Relief Model NAD83 Latitude & U.S. Atlantic & Gulf Coast 1950-1999 m MLLW 0.5 feet (NOAA, 2006) Longitude

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 Universal Transverse Mercator (UTM) Zone 17, NAD83 to FL-West NAD83: SuperTrans 1.01.3362 (Deltares, 2010) and Corpscon 6.0 (USACE, 2010).

 National Geodetic Vertical Datum of 1929 (NGVD) to NAVD: Corpscon 6.0 (USACE, 2010).

 Mean Low Water (MLW) and Mean Lower Low Water (MLLW) to NGVD and NAVD: VDATUM 2.3.5 (NOAA, 2012).

For all coordinate conversions, a ratio of 3,937 U.S. feet to 1,200 meters was assumed.

2.2 Water Levels

CPE 2010 Field Measurements

Tide gages were deployed by CPE between June 11 and June 23, 2012 at the locations shown in Table 2 and Figure 3. Processed water level data from the tide gages was given in feet NAVD every 10 minutes. Dates and times were given relative to Eastern Daylight Time (EDT). In general, the water levels at the Main Channel tide gage were 0.13 to 0.36 feet higher than those at the Perico Bayou tide gage. However, at all 3 gages, water levels compared favorably with nearby measurements by USGS (see Figure 4), ranging from -1.51 to +1.78 feet NAVD.

Table 2: Tide Gage Locations

Latitude Longitude Tide Gage Deployed or Maintained by (°N) (°W) ANMF1 27.534444 82.734444 University of South Florida (USF) Anna Maria Outside* 27.496700 82.713300 WWW Tide and Current Predictor & NOAA Foot Bridge 27.497706 82.669249 Coastal Planning & Engineering, Inc. Main Channel 27.484842 82.696802 Coastal Planning & Engineering, Inc. Palma Sola 27.523889 82.646389 U.S. Geological Survey (USGS) Perico Bayou 27.512430 82.682015 Coastal Planning & Engineering, Inc. *NOTE: This gage was operational July 1, 1990 to October 31, 1990 only.

Typical Water Level Conditions

Observed water levels and astronomical tides at the north end of Anna Maria Island (ANMF1) are shown in Figure 5. The difference between the two is known as the “residual tide”. During the first half of the deployment period, the residual tides at ANMF1 were less than 0.5 feet. However, during the second half of the deployment period, the residual tides increased due to rainfall and storm surge from Tropical Storm Debby, which formed in the Gulf of Mexico on June 23 and made landfall near Cedar Key on June 27. For this reason, the water levels in Figure 4 and Figure 5 were not representative of average conditions. Furthermore, water levels at the

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Figure 3: Tide Gage Locations.

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Figure 4: June 2012 Water Level Measurements by CPE and USGS.

Figure 5: Observed Water Levels and Astronomical Tides at ANMF1 during the June 2012 Deployment Period.

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Main Channel tide gage were consistently higher than those at the at the Perico Bayou tide gage. Thus, using the elevated water levels in Figure 4 could affect the simulations of flushing and flow direction. For these two reasons, water levels from a more typical period were identified for use in the tidal flushing analysis.

Typical water levels at ANMF1 over a two week period in 2011 appear in the top half of Figure 6. The period shown in Figure 6 encompasses the typical spring-neap tidal variation, with relatively low residual tides. Concurrent water levels in the open Gulf were estimated by adding the residual tides at ANMF1 to the astronomical tide at the Anna Maria Outside tide gage near Manatee Avenue & Gulf Drive. The resulting water levels in the bottom half of Figure 6 were used to drive the regional model simulations, which are discussed later in this report.

2.3 Weather Data

Wind velocities and rainfall during the deployment period were taken from 6 minute measurements provided at ANMFI (USF, 2012). Wind velocities and rainfall values during average conditions were developed based on daily values at ANMFI (USF, 2012) and the Sarasota-Bradenton Airport between January 1 and December 31, 2011 (Weather Underground, 2012). The rainfall values and wind velocities used in the model simulations are detailed later in this report.

2.4 Seagrass

Seagrass locations from the Florida Fish and Wildlife Conservation Commission (FFWCC, 2011) were used to set bottom friction values in the Delft3D-FLOW model. The seagrass locations provided by FFWCC were a compilation of statewide data from aerial photographs, field measurements, and other sources between 1987 and 2008 (FFWCC, 2011). Seagrass locations near the project area appear in Figure 7.

2.5 Forest Locations

Forest and brush locations were used to set bottom friction values to reflect the overgrown condition of the existing mosquito ditches (see Figure 8). The locations of forested areas were digitized from 2010-2011 aerial photographs, and appear in Figure 7.

3. MODEL GRIDS

Three grids were used in the modeling study:

1. A Regional Flow Grid encompassing all of Sarasota Bay, Anna Maria Sound, and Tampa Bay.

2. A local Calibration Grid used for initial model simulations.

3. A Local Model Grid, with tighter grid spacing to resolve the restored and extended mosquito ditch in Figure 2. 9 COASTAL PLANNING & ENGINEERING, INC.

Figure 6: Observed and Simulated Water Levels during Average Conditions.

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Figure 7: Seagrass and Forest Locations near the Project Area.

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Figure 8: Typical Condition of the Existing Mosquito Ditches. Date of Photograph: February 3, 2012.

Grids appear in Figure 9 through Figure 11. The Calibration Grid and Local Model Grid covered the same area. However, as shown in Figure 10 and Table 3, the Local Model Grid had a tighter spacing to better replicate the shape of the mosquito ditch. All three (3) grids were constructed in Cartesian coordinates based on the Florida State Plane Coordinate System, West Zone, North American Datum of 1983 (FLW-NAD83). Grid properties are listed in Table 3.

All three (3) grids follow the Deltares (2011) guidelines for smoothing and orthogonality (see Table 3). The smoothing represents the change in cell size between two rows of grid cells. A smoothing value of 1.1 indicates that the cell size between two rows of grid cells increases by 10%. The maximum smoothing value recommended by the model’s developer is 1.2. The orthogonality is equivalent to the angle between the north-south and east-west grid lines. The angles between the north-south and east-west grid lines should be at least 87.7 degrees within the area of interest.

Bathymetry over the Regional Flow Grid was based on the data sources in Table 1. The 2012 surveys by Stantec were used first, followed by the remaining sources in the order shown in Table 1. The resulting bathymetry appears in Figure 12.

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Table 3: Delft3D Grid Characteristics

Regional Calibration Local Flow Recom- Flow Grid Grid Grid mended # of East-West Cells 343 499 781 -N/A- # of North-South Cells 563 420 720 -N/A- East-West Spacing (feet) - Min. 58 7 2 -N/A- East-West Spacing (feet) - Max. 1,846 328 328 -N/A- North-South Spacing (feet) - Min. 35 12 3 -N/A- North-South Spacing (feet) - Max. 1,339 328 328 -N/A- East-West Smoothness - Min. 1.00 1.00 1.00 -N/A- East-West Smoothness - Max. 1.08 1.22 1.23 1.2 North-South Smoothness - Min. 1.00 1.00 1.00 -N/A- North-South Smoothness - Max. 1.11 1.19 1.21 1.2 Orthogonality (deg.) - Min. 88.3 90.0 90.0 87.7 Orthogonality (deg.) - Max. 90.0 90.0 90.0 -N/A-

Figure 9: Local Flow Grid.

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CULVERT CULVERT

Figure 10: Calibration Grid and Local Flow Grid near Culvert under Manatee Avenue.

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Local Flow Grid & Calibration Grid

Figure 11: Regional Flow Grid.

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Figure 12: Regional Flow Grid Bathymetry.

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Bathymetry over the Calibration Grid and the Local Flow Grid was based on the 2012 surveys by Stantec, followed by the July 2012 LIDAR survey, the USGS (2004) Digital Elevation Models, and the 1953-1954 hydrographic surveys by NOAA (see Table 1). Similar to the Regional Flow Grid, the most recent data sources were used first, followed by the remaining data sources going back in time. Bathymetry and topography over the Local Flow Grid appears in Figure 13 and Figure 14. The bathymetry and topography over the Calibration Grid is similar in appearance.

4. MODEL CALIBRATION

4.1 Model Forcing

Initial calibration of the Delft3D-FLOW model was performed using the water level measurements in Figure 4 and the Calibration Grid. Water levels at the Perico Bayou tide gage provided the forcing on the northern side of the grid (see thin black line in Figure 4 and pink line in Figure 13). Water levels at the Main Channel tide gage provided the forcing on the eastern side of the grid (see blue dashed line in Figure 4 and pink line in Figure 13). Output from the model was evaluated at the Foot Bridge (see Figure 3 and orange dashed line in Figure 4).

Additional model forcing was provided using wind and rainfall measurements at ANMF1 (USF, 2012) (see Figure 15 and Figure 16). Wind speeds ranged from 0 to 29 mph, with the highest wind speeds occurring on June 20. Daily rainfall was on the order 1 to 2 inches. Rainfall values were comparable to those at the Sarasota/Bradenton Airport during the end of the calibration period. During the beginning of the calibration period, ANMF1 reported more rainfall than occurred at the airport. It should also be noted that there were a few periods (June 15-18) during which the weather instrumentation at ANMF1 malfunctioned.

4.2 Calibration Parameters

Calibration of the model was conducted by varying the value of Manning’s n, which was used as the bottom friction coefficient in the Delft3D-FLOW model. All other model parameters were set to their default values.

As shown in Figure 7, much of the seafloor surrounding the project area is covered by seagrass. Seagrass beds often increase the bottom friction. The way to account for this effect is to increase the value of Manning’s n by 0.010 to 0.030 (Lloyd Environmental, 2006; Hauck and Brown, 1990; Loder, 2008). To assess the sensitivity of the water levels to variable friction, the schematizations listed in Table 4 were examined.

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Figure 13: Local Flow Grid Bathymetry and Topography.

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Figure 14: Local Flow Grid Bathymetry and Topography near the Project Area.

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Figure 15: Wind Velocities at ANMF1 during the Calibration Period.

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Figure 16: Rainfall during the Calibration Period.

Table 4: Perico Preserve Delft3D-FLOW Calibration Summary

Simulated – Observed Calibration Manning’s n Water Level at the Run Foot Bridge (feet) Bare Sand Seagrass Land* Mean RMS A 0.020 0.020 0.040 -0.10 0.19 B 0.020 0.030 0.040 -0.07 0.20 C (Selected) 0.015 0.025 0.040 -0.09 0.19 D 0.015 0.015 0.040 -0.11 0.20 E 0.012 0.015 0.040 -0.11 0.20 * Areas above Mean Higher High Water (+0.63 feet NAVD).

Manning’s n coefficients for floodplains are typically on the order of 0.035 for farmland, 0.050 for light brush, and 0.15 for tress (LMNO Engineering, 2000). As a first approximation, a Manning’s n value of 0.040 was assumed above Mean Higher High Water (MHHW +0.63 feet NAVD, NOAA, 2004). Below MHHW, Manning’s n values were based on the seagrass locations shown in Figure 7 and the schematizations listed in Table 4. A typical friction map during the initial calibration appears in Figure 17. Given the shallow depths near the project area, all model runs were conducted in depth-averaged mode.

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Figure 17: Typical Bottom Friction Map during the Initial Calibration Phase.

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4.3 Culvert

Since the existing mosquito ditches leading into the culvert under Manatee Avenue (Figure 2) were heavily overgrown (see Figure 8), they offered little or no hydraulic connection between Perico Bayou (east of the project area) and the water body south of the culvert. As such, the effect of the culvert on water levels at the Foot Bridge was negligible. For this reason, the culvert was not included in the initial calibration runs. Later model runs, which used the more detailed Local Flow Grid, included the culvert. The implementation of the culvert in these simulations is discussed later in this report.

4.4 Initial Calibration Results

Simulated and observed water levels during the selected Calibration Run C appear in Figure 18. The agreement between the simulated and observed water levels was within acceptable ranges and the friction scheme of Calibration Run C provided the basis for subsequent model runs.

Figure 18: Simulated and Observed during the Initial Calibration Phase.

4.5 Sensitivity Analysis and Model Refinement

To examine the sensitivity of the model to wind, rainfall, and grid spacing, Calibration Run C was repeated with the following modifications:

1. Winds not included, rainfall included. 23 COASTAL PLANNING & ENGINEERING, INC.

2. Rainfall not included, winds included.

3. Winds and rainfall not included.

4. Winds and rainfall included, with the Local Flow Grid instead of the Calibration Grid.

The final modification listed above included the following changes to the model setup:

 The use of the more detailed Local Flow Grid, instead of the Calibration Grid (see Figure 10).

 The inclusion of the culvert in Figure 2 and Figure 19. Given the fine grid spacing, the most efficient means of incorporating the culvert into the model was to modify the bathymetry and the bottom friction mapping (see Figure 20). Based on the dimensions of the structure and the average invert elevation of -2.7 feet NAVD, the ceiling of the culvert was located at roughly +3.3 feet NAVD (see Figure 19). A Manning’s n value of 0.015 was assumed inside the culvert.

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+3.3 FEET NAVD APPROX.

6 FEET 9 FEET

INVERT ELEV. -2.6 to -2.8 FEET NAVD

Figure 19: February 3, 2012 Photograph of Culvert under Manatee Avenue.

Figure 20: Close-up of Local Flow Grid Bathymetry near Culvert under Manatee Avenue.

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 An additional bottom friction type for forest and heavy brush was included to better account for the overgrown condition of the existing mosquito ditches (see Figure 8). The locations of the forest and heavy brush areas were based on the 2010-2011 aerial photographs, and appear in Figure 7. Based on the listing provided by LMNO Engineering (2000), the most appropriate Manning’s n value for these areas would be 0.075. This value was applied in all forest and heavy brush areas above MHHW (see Figure 7). It was also applied to all forest and heavy brush areas below MHHW in the area bounded by Manatee Avenue, Perico Bayou, the Perico Island housing development, and the Harbour Isle housing development. The resulting friction mapping appears in Figure 21.

Results at the Foot Bridge given the modifications above are presented in Figure 22 and Table 5. As shown therein, the inclusion of wind and rain had a minor effect on the model results. The use of the finer modeling grid and the addition of the culvert had almost no effect on the model results. Thus, the selected friction scheme with the additional forest and brush category was used in the model.

Table 5: Summary of Wind and Rainfall Sensitivity Analysis

Difference (feet) between Calibration Run C and Run C with …

Rain Neglected, Rain Included, Rain Neglected, Rain Included, Wind Included, & Wind Neglected, & Wind Neglected, & Wind Included, & Calibration Grid Calibration Grid Calibration Grid Local Flow Grid Minimum -0.10 -0.08 -0.09 -0.02 Mean -0.01 0.01 0.01 0.00 RMS 0.01 0.03 0.03 0.00 Maximum 0.01 0.21 0.19 0.01

4.6 Final Calibration Results

The final calibration setup utilizes the Local Flow Grid (Figure 9 and Figure 10), the wind velocities in Figure 15, the rainfall data in Figure 16, the bottom friction mapping in Figure 21, the assumed bathymetry inside the culvert as shown in Figure 20, and the water level data collected between June 12 and June 23, 2012. Final calibration results based on this setup appear in Figure 22 (bottom plot) and in Figure 23 through Figure 26. In general, the highest currents occur in constricted areas such as the culvert interior, the Foot Bridge, and the Manatee Avenue bridge between Perico Island and Flamingo Drive. Over the calibration period, current speeds at those locations are on the order of 2 to 3 feet/second during peak flood or ebb.

Inside the culvert, the highest estimated water level is +1.62 feet NAVD, and the currents are ebb-dominated (see Figure 25). Since the highest water level is below the ceiling of the structure (see Figure 19), the treatment of the culvert in the model is representative of existing conditions.

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Figure 21: Bottom Friction Map Used in the Final Calibration Run and Subsequent Model Runs.

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Figure 22: Wind and Rainfall Sensitivity Analysis Results.

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Figure 23: Typical Simulated Currents during the Calibration Period.

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Figure 24: Typical Simulated Water Levels during the Calibration Period.

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Figure 25: Simulated Currents and Water Levels in the Culvert Interior, Final Calibration.

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Figure 26: Simulated Currents under the Manatee Avenue Bridge, Final Calibration.

At the Manatee Avenue bridge, the predominant direction of the current during the calibration period is from south to north (see Figure 26). This is due to the characteristics of the observed water levels that were used to drive the model. It should be noted that the calibration period included the effects of Tropical Storm Debby. Over the calibration period, the water levels at the Main Channel tide gage were 0.13 to 0.36 feet higher than those at the Perico Bayou tide gage (see Figure 4). As a result, estimated currents near the Manatee Avenue bridge were from north to south during the majority of the calibration period. Given the final calibration results, the schematization of the bottom friction and the magnitudes of the currents were acceptable. However, assessment of the typical flow patterns and flushing times suggested the model would require model inputs that would be more representative of average conditions. As a result, the production runs were not driven by water levels observed during Tropical Storm Debby, but rather water levels that are more representative of average conditions. Modeling parameters used in the final calibration and subsequent model simulations appear in Table 6.

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Table 6: Delft3D Calibration Parameters, Perico Preserve

Min. Default Max. Selected Value

Delft3D-FLOW Model, Flow Parameters:

Number of Vertical Layers 1 1 100 1 Bottom Friction Coef. for Flow: Chezy's Friction Coef. C 0 65 1000 Not Used Bare Bottom, 0.015 Seagrass, 0.025 Manning's n 0.000 None 0.150 Floodplain, 0.040 Forest/Brush, 0.075 Horiz. Eddy Viscosity (m2/s) 0 10 100 1 Not Applicable for Vertical Eddy Viscosity (m2/s) 0 1 x 10-6 100 Depth-Averaged Models 1 Horiz. Eddy Diffusivity (m2/s) 0 10 1000 (CPE, 2008) Not Applicable for Vertical Eddy Diffusivity (m2/s) 0 1 x 10-6 1000 Depth-Averaged Models Pollutant Transport Advection Scheme -N/A- Cyclic -N/A- Van Leer Wind Stress Formulation Default formulation

5. REGIONAL MODEL SIMULATIONS

A regional model simulation was conducted to provide local water levels that would be representative of average conditions. The inputs for the regional model simulation were the grid in Figure 11, the bathymetry in Figure 12, and the following:

5.1 Water Levels

Water level data at Port Manatee (27° 38.3' N, 82° 33.7' W, http://tidesandcurrents.noaa.gov) and ANMF1 was reviewed to identify a recent, spring-neap tidal cycle with low residual tides (i.e.: less than 0.5 feet). Water levels between May 24 and June 7, 2011 met this requirement (see Figure 6). To develop a set of input water levels for the Regional Flow Grid, the following steps were taken:

1. The estimated water levels along Anna Maria Key, Bradenton Beach (see Figure 6, lower half, black dashed line) were smoothed using a 60 minute running average.

2. The smoothed water levels were then combined into a 14 day “loop” to be repeated as needed.

The resulting “Open-Gulf” water levels appear in Figure 27.

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Figure 27: Average Condition Water Levels.

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5.2 Winds

Wind velocities during average conditions were developed based on the average wind speeds at the north end of Anna Maria Island (ANMF1, USF, 2012) from January 1 and December 31, 2011: 9.8 mph, north-northeast (32°). This wind velocity was comparable to average of the daily values at the Sarasota-Bradenton Airport during the same period: 7.8 mph, east-northeast (63°) (Weather Underground, 2012).

5.3 Rainfall

Rainfall values at ANMF1 over 2011 appeared to be out of scale, reporting an average of 451 inches between January 1 and December 31, 2011. Accordingly, rainfall was based on the average of the daily values at the Sarasota-Bradenton Airport over the same period: 44 inches per year or 0.12 inches/day (Weather Underground, 2012).

5.4 Bottom Friction

Bottom friction was schematized in the same manner as the final calibration run. The friction map appears in Figure 28.

5.5 Regional Model Results

Typical results from the regional model simulation appear in Figure 27 (middle and bottom), Figure 29, Figure 30, and Figure 31. In general, the regional model results suggest the following:

 Simulated water levels near the open boundaries of the Local Flow Grid are similar to those in the Gulf of Mexico. However, they lag the water levels in the Gulf by 1 to 2 hours (see Figure 31).

 Under average conditions, the mean water level elevation at the northern side of the Local Flow Grid (Perico Bayou tide gage) is similar to the mean water level elevation on the western side of the Local Flow Grid south of Manatee Avenue (Main Channel tide gage) (see Figure 31).

 Under average conditions, the water levels just east of the Main Channel tide gage are within 0.37 feet of water levels at the Perico Bayou tide gage (see Figure 30).

The estimated water levels shown in Figure 27 (middle and bottom) and Figure 31 were used as inputs on the open boundaries of the Local Flow Grid (see Figure 13). Local flow patterns and tidal flushing times under average conditions are detailed in the next section.

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Figure 28: Bottom Friction Map Used in the Regional Model.

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Depth-Averaged Currents (feet/s), Day 0.875 of Simulation

Figure 29: Typical Simulated Currents over the Regional Flow Grid.

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Water Levels (feet NAVD), Day 0.875 of Simulation

Figure 30: Typical Simulated Water Levels over the Regional Flow Grid.

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Figure 31: Comparison of Open-Gulf Water Levels to Water Levels on the Open Boundaries of the Local Flow Grid.

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6. LOCAL MODEL SIMULATIONS GIVEN THE PROPOSED ALTERNATIVES

The initial design of the Perico Preserve Habitat Restoration appears in Figure 2. The flow and tidal flushing of the initial design was simulated (Alternative 2) and compared to a no-action scenario (Alternative 1). Based on the results of the initial simulations, Alternative 3 was developed with slight modifications to the mosquito ditch and flushing cuts. A fourth alternative was simulated to evaluate the effects of a potential clog within the mosquito ditch. The simulated alternatives are summarized below:

 Alternative 1: No-Action Scenario. No restoration features are included in this alternative.

 Alternative 2: April-September 2012 Design. This alternative includes the proposed rookery pond, vegetated with seagrass, two tidal flushing cuts and the restoration of the mosquito ditch (Figure 2 and Figure 32).

 Alternative 3: October 2012 Design (Figure 33 and Figure 34). This alternative is similar to Alternative 2, except for the following:

o The restored and extended mosquito ditch will include two “turn-around” areas at the sharp bends in the channel to facilitate use by kayakers.

o To accommodate a timber pedestrian bridge, the alignment of the mosquito ditch extension will be slightly different near its northeastern end.

o The sides of the flushing cuts between the Rookery Pond and Perico Bayou will be armored with rip-rap or bags of oyster shells. The armoring was simulated by increasing the value of Manning’s n to 0.033 (Furniss, et al, 2006; Te-Hsing, et al, 2010).

 Alternative 4: October 2012 Design with Clogged Mosquito Ditch. This alternative was simulated to evaluate what might occur if the mosquito ditch became clogged near the timber pedestrian bridge (see Figure 35).

Each alternative was evaluated using the Local Flow Grid (Figure 9 and Figure 10), the average wind and rainfall values described in the previous section, the water level boundary conditions in Figure 27 (middle and bottom), and the calibration parameters in Table 4.

To simulate tidal flushing, the following scenarios were considered:

 Scenario A: A tracer with an initial concentration of 1 kg/m3 (1,000 mg/L) in the Rookery pond only (see Figure 36). This scenario was simulated for Alternatives 2, 3, and 4.

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 Scenario B: A tracer with an initial concentration of 1 kg/m3 (1,000 mg/L) in Spoonbill Bay and Perico Bayou under Alternatives 1, 3, and 4, and in the Rookery Pond given Alternatives 3 and 4 (see Figure 37).

6.1 Alternative 1: No-Action Scenario

The No-Action Scenario was simulated to evaluate the present circulation patterns under average conditions. It was also used as a basis to compare to the potential impacts of each alternative on circulation. The bathymetry and bottom roughness given the Without-Project Scenario appear in Figure 13, Figure 14, Figure 20, and Figure 21. To cover the initial warm-up period and a spring-neap tidal cycle, the simulation period was 16 days.

Model results given the No-Action Scenario appear in Appendix A and Figure 38 to Figure 41. Under average conditions, estimated flows in the culvert interior tend to be flood dominated, rather than ebb dominated (see Figure 40), with peak flood currents on the order of 1.0 feet/second during spring tides, and peak ebb currents on the order of -0.6 feet/second.

Outside the south end of the culvert, the model suggests that currents are very low under average conditions (see Figure 41). Peak flood currents are on the order of 0.10 feet/second, while peak flood currents are on the order of 0.05 feet/second.

At the bridge between Perico Island and Flamingo Drive, the model suggests that flows under average conditions switch direction frequently due to the interaction of the incoming and outgoing water from Perico Bayou and Palma Sola Bay. The highest currents under average conditions appear to be from north to south, with peak speeds near 1.8 feet/second during spring tides and southerly-directed flows, and 1.3 feet/second during northerly-directed flows (see Figure 42).

To simulate the existing tidal flushing patterns, Spoonbill Bay and Perico Bayou were simulated with a tracer that had an initial concentration of 1 kg/m3 (1,000 mg/L) (Tracer Scenario B, Figure 37). The simulation of Alternative 1 was then repeated to evaluate tidal flushing patterns. Biological, chemical, or radioactive decay of the tracer was assumed to be negligible. The tracer concentrations of the incoming water from the Gulf Intracoastal Waterway and Tampa Bay were assumed to be zero. The flushing times at any given location were the times required for the concentration of the tracer to drop below 1 to 10% of its original value (i.e.: 0.10 to 0.01 kg/m3). To facilitate the evaluation of the results, tracking points were established at key locations within the project area and the model grid (see Figure 37 and Table 8).

Tidal flushing patterns given the No Action Scenario appear in Table 8 and Appendices A and B. During the first day of the simulation, the model suggests that the tracer will spread into the existing mosquito ditch, entrance to Spoonbill Bay, and the channel between Perico Bayou and Palma Sola Bay. Dilution of the tracer to 10% of initial concentration within Spoonbill Bay and Perico Bayou is estimated to take 6 to 7 days. Dilution of the tracer to the same level in the mosquito ditch is estimated to take 7 to 8 days. An additional 5 to 6 days is required to flush the tracer to 1% of its initial concentration in Perico Bayou. In Spoonbill Bay and the existing

41 COASTAL PLANNING & ENGINEERING, INC. mosquito ditch, the amount of time required to flush the tracer to 1% of its initial concentration would likely exceed 16 days.

6.2 Alternative 2: April-September 2012 Design

Alternative 2 is the preliminary April-September 2012 Design. It includes the basic site plan as depicted in the April 2012 construction drawings, along with mosquito ditch and flushing cuts on the September 2012 survey drawing (Stantec, 2012). The bathymetry and topography used for this alternative appear in Figure 2. To account for the various design features on bottom roughness, the values of Manning’s n were modified as shown in Table 7 and Figure 32:

Table 7: Bottom Roughness Coefficients for Alternatives 2 through 4

Project Feature Manning’s n Note Main Pond 0.025 Seagrass planting area Project Area Outside 0.015 Below MHHW (+0.63 feet NAVD) Main Pond 0.040 Above MHHW (+0.63 feet NAVD) Flushing Cuts 0.015 Below MHHW (+0.63 feet NAVD) Mosquito Ditches 0.015 Below MHHW (+0.63 feet NAVD) Rip-Rap or Oyster Shell 0.033 Sides of flushing cuts, Alternatives 3 & 4 only Armoring Remaining Areas See Figure 21 Final Calibration Values

To evaluate tidal flushing times under Tracer Scenario A, the main pond was filled with a tracer that had an initial concentration of 1 kg/m3 (1,000 mg/L) (see Figure 36). Since Alternative 2 was a preliminary design, Tracer Scenario B was not simulated. The time of the simulation and the other assumptions regarding the tracer were the same as those of Alternative 1, Tracer Scenario B.

Model results given the Alternative 2 appear in Appendices A and B, Figure 38 to Figure 42, Figure 43, and Table 9. In general, the model results suggest the following:

 The April-September 2012 Design will not have a large effect on circulation patterns except near the project area itself (see Figure 38 to Figure 42 and Figure 43). The potential effects of Alternative 2 on circulation would be:

o The introduction of flow into the main pond through the two flushing cuts in Figure 2 and Figure 43.

o Minor changes to the current speeds under the Manatee Avenue. Bridge between Perico Island and Flamingo Drive (see Figure 42). Project-induced changes to the current under typical conditions would be on the order of 0.05 feet/second, but could approach 0.3 feet/second during spring tides.

o Increased current speed in the interior of the culvert between low water slack and mid-tide. These increases are most obvious on the second half of days 5 through 7 and the beginning of days 9 through 15 (see Figure 40). Under the No-Action

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Scenario, current speeds during these times are negligible. However, by providing a hydraulically efficient connection between the culvert and the main pond, the construction of Alternative 2 would allow water to flow through the culvert and the ditch during these times, raising the current speed to the 0.2 to 0.3 foot per second range. Outside the southern entrance of the culvert, project- induced increases in current speed would occur in similar proportions (see Figure 41). However, the current speeds at that location are only about 10% of those inside the culvert (Figure 40 versus Figure 41).

 Under the April-September 2012 design and Tracer Scenario A, the model estimates that approximately 2 to 3 days are required to flush the tracer to 10% of its original concentration (see Table 9). An additional 5 days would be needed to dilute the tracer to 1% of its original concentration (see Table 9). The majority of the tidal flushing will occur through the two flushing cuts on the eastern side of the project area (see Appendix A animations). However, the model results do show some spreading of tracer into the extended mosquito ditch. Under Tracer Scenario A, the time required the flush the mosquito ditch to 10% of the original tracer concentration is estimated to range from 3 to 4 days, with dilution of the tracer to 1% of its original concentration requiring 8 days (see Table 9). Over Perico Bayou and Palma Sola Bay as a whole, the estimated 1% flushing time under Tracer Scenario A is on the order of 9 to 11 days (see Appendix A animations).

6.3 Alternative 3: October 2012 Design

Alternative 3 is the revised design, which includes a timber pedestrian bridge, armoring on the Rookery Pond’s flushing cuts, and two “turn-around” areas along the extended mosquito ditch to facilitate use by kayakers (see Figure 33 and Figure 34). The bathymetry and topography for Alternative 3 are similar to that of Alternative 2, except for the extended mosquito ditch (see Figure 33). To account for the various design features on bottom roughness, the values of Manning’s n were modified as shown in Table 7 and Figure 34.

Both tracer scenarios were simulated for Alternative 3 (see Figure 36, Figure 37, Table 8, and Table 9). Model results given Alternative 3 appear in Figure 44 through Figure 49, Table 8, Table 9, and Appendices A and B. In general, the model results suggest the following:

 Flow patterns would be very similar to those of Alternative 2. Project-induced changes in flow would also be similar to those of Alternative 2 (compare Figure 44 through Figure 49 with Figure 38 through Figure 43).

 Under Tracer Scenario A, the flushing of pollutants out of the Rookery Pond would be similar to that of Alternative 2, with the majority of the tidal flushing occurring through the two flushing cuts on the eastern side of the project area (see Appendix A animations). The corresponding flushing times would also be very similar to Alternative 2 (see Table 9).

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 Under Tracer Scenario B:

o The time required to dilute the tracer to concentration to 10% of its original value in the Rookery Pond would be 6 to 7 days instead of 2 to 3 days (see Table 8, Table 9, and Appendix A animations) under Tracer Scenario A. Likewise, the time required to dilute the tracer concentration to 1% of its original value ranges from 12 to 14 days instead of 7 to 8 days. Since the tracer is spread over a larger area (compare Figure 36 and Figure 37), the times required to flush the tracer out of the Rookery Pond under Tracer Scenario B would be several days longer than those of Tracer Scenario A.

o The impact of the additional tracer in the Rookery Pond on flushing times in the mosquito ditch, the culvert, and Spoonbill Bay would be minor. There are two reasons for this finding. First, the model results for Alternative 3, in general, suggest that most of the tidal flushing out of the Rookery Pond would occur through the flushing cuts on the eastern side of the project area (see Appendix A animations). Second, under Alternative 3, the cross-sectional area of the mosquito ditch would be somewhat larger than it is under the existing conditions (Alternative 1), with less brush and debris to block flow (see Figure 8, Figure 21, and Figure 34). As such, the improved condition of the ditch would likely offset the effects of the additional pollutants from the Rookery Pond.

o The additional tracer in the Rookery Pond would increase the flushing times in Perico Bayou and the connecting channel into Palm Sola Bay by at least one day (see Table 8).

6.4 Alternative 4: October 2012 Design with Clogged Mosquito Ditch

Alternative 4 was simulated to examine what might occur if the mosquito extension became clogged near the proposed pedestrian bridge (see Figure 33 and Figure 35). Model results given Alternative 4 appear in Table 8, Table 9, and Appendices A and B. In general, these results suggest the following:

 In the majority of the Rookery Pond flushing times under either tracer scenario (A or B) would be similar to those of Alternatives 2 and 3, under which the mosquito ditch is not clogged (see Table 8 and Table 9). The results for Alternatives 2 and 3 generally suggest that most of the tidal flushing would occur through the two flushing cuts on the eastern side of the project area. For this reason, a clog in the mosquito ditch would not likely have an impact on flushing times in most of the pond. Likewise, flushing times in Perico Bayou and the connecting channel into Palma Sola Bay would be similar to those of Alternative 3.

 Near the southwest corner of the pond (Rookery W. and Mosq. Ditch E), flushing times under Tracer Scenario B could decrease versus Alternative 3 (see Table 8), since there would be no pollutants entering these areas from Spoonbill Bay via the mosquito ditch. 44 COASTAL PLANNING & ENGINEERING, INC.

 In the isolated, northeast end of the mosquito ditch (Mosq. Ditch E), flushing time times under Tracer Scenario A could be slightly lower than Alternative 3 (see Table 9). This result is due to the fact that there would be no pollutants entering the area between the proposed pedestrian bridge and the eastern kayak turn-around (see Figure 33). Since the pollutants would be spread over a shorter length if the ditch were clogged (see Figure 35), less time might be required to flush the northeast end of the clogged ditch under Tracer Scenario A.

 In the culvert and the southwestern section of the mosquito ditch, flushing times under Tracer Scenario B would increase versus Alternative 3 (see Table 8). The clog in the ditch would force all of the pollutants to be flushed via the culvert, resulting in slightly longer flushing times.

Overall, the model results suggest that changes in flushing times given a clog in the mosquito ditch would be relatively small (< 1 day). As the majority of tidal flushing in the Rookery Pond would occur via the two flushing cuts on its eastern side, a clog in the mosquito ditch should not adversely affect the tidal flushing of the main pond.

6.5 Sediment Mobility

The model results were also used to estimate the likelihood of tidal currents to mobilize sediments within the restoration area and the connections with the adjacent bays. In general, the model results suggest the current speeds within the restoration area are slower than the critical velocities necessary to scour a channel or continuously mobilize sediment. The current speeds within the flushing channels and mosquito ditch throughout a tidal cycle are less than 0.2 feet per second (Figure 35). Based on the mean sediment size determined during the granularmetric analysis of the sand samples collected from the restoration area (Appendix C), 0.18 millimeters, the mean velocity for stable channel design is 0.6 feet per second (Vanoni, 1977). As a result, sediment is not expected to mobilize in these areas. Within the interior of the culvert, velocities approach 0.9 feet per second during short periods of the spring tide (Figure 35). During these peak tides, there is possibility sediment may mobilize, as has been observed under existing conditions. Overall, the model results do not suggest the proposed alternatives would affect the sediment mobility within the vicinity of the culvert.

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Figure 32: Bottom Friction Map for Alternative 2.

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TIMBER BRIDGE & MODIFIED CHANNEL ALIGNMENT KAYAK TURN-AROUNDS

Figure 33: Alternative 3 Design Changes.

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RIP-RAP OR SHELL OYSTER ARMORING

Figure 34: Bottom Friction Map for Alternative 3.

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CLOGGED DITCH

Figure 35: Alternative 4 Clogged Bathymetry.

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Figure 36: Initial Tracer Location (Dark Red) for Scenario A, Alternatives 2, 3, and 4.

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NOTE – Initial concentration in the Rookery is assumed to be zero for Alternative 1 (No Action).

Figure 37: Concentration Tracking Points & Initial Tracer Location (Dark Red) for Scenario B, Alternatives 1, 3, and 4.

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Figure 38: Typical Spring-Tide Flood Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 2.

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Figure 39: Typical Spring-Tide Ebb Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 2.

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Figure 40: Simulated Currents in the Culvert Interior under Average Conditions Given Alternatives 1 and 2.

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Figure 41: Simulated Currents outside the South End of the Culvert under Average Conditions Given Alternatives 1 and 2.

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Figure 42: Simulated Currents under the Manatee Avenue Bridge under Average Conditions Given Alternatives 1 and 2.

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Table 8: Perico Bayou Tidal Flushing Results, Scenario B, Tracer in Spoonbill Bay, Perico Bayou, & Rookery

Flushing Time (days) to Given % of Original Tracer Concentration

Station Name FL-West NAD83 Alternative 1 Alternative 3 Alternative 4 E (feet) N (feet) to 1% to 10% to 1% to 10% to 1% to 10%

MAIN POND:

ROOKERY W 436,730 1,151,857 * * 14.2 7.0 11.6 6.4 ROOKERY MIDDLE 437,166 1,152,125 * * 13.2 6.3 11.5 6.3 ROOKERY NE 437,342 1,152,393 * * 12.4 6.2 11.3 6.2 ROOKERY SE 437,693 1,151,948 * * 12.4 6.2 12.2 6.2

MOSQUITO DITCH:

MOSQ DITCH E 436,575 1,151,735 * * 15.2 8.0 11.7 6.4 CULVERT N 435,089 1,150,240 > 16 7.6 > 16 7.7 > 16 8.3 CULVERT INSIDE 435,086 1,150,204 > 16 7.4 > 16 7.3 > 16 7.9 CULVERT S 435,070 1,150,128 > 16 7.3 > 16 7.3 > 16 7.4

SPOONBILL BAY:

SPOONBILL BAY N 435,080 1,149,409 > 16 6.9 > 16 7.0 > 16 6.8 SPOONBILL BAY S 435,019 1,148,577 > 16 6.3 > 16 6.3 > 16 6.3

MISC. LOCATIONS:

FOOTBRIDGE 439,199 1,150,681 12.2 6.7 13.3 7.2 12.9 7.2 MANATEE AV 439,307 1,150,177 12.3 6.9 13.3 7.3 13.1 7.3 MAIN CHANNEL 432,081 1,145,973 5.8 * 5.8 * 5.8 * PERICO BAYOU 435,137 1,156,360 1.0 0.0 1.0 0.0 1.0 0.0 ROOKERY OUTSIDE 438,323 1,152,539 11.1 5.9 12.2 6.9 12.1 6.9

NOTE: *Concentration never exceeds 1% or 10% at these locations.

57 COASTAL PLANNING & ENGINEERING, INC.

Table 9: Perico Bayou Tidal Flushing Results, Scenario A, Tracer in Rookery Only

Flushing Time (days) to Given % of Original Tracer Concentration

Station Name FL-West NAD83 Alternative 2 Alternative 3 Alternative 4 E (feet) N (feet) to 1% to 10% to 1% to 10% to 1% to 10%

MAIN POND:

ROOKERY W 436,730 1,151,857 7.5 2.5 7.5 2.5 7.6 2.6 ROOKERY MIDDLE 437,166 1,152,125 7.4 2.3 7.4 2.3 7.4 2.3 ROOKERY NE 437,342 1,152,393 7.3 2.2 7.3 2.2 7.3 2.2 ROOKERY SE 437,693 1,151,948 7.3 2.2 7.3 2.2 7.3 2.2

MOSQUITO DITCH:

MOSQ DITCH E 436,575 1,151,735 7.9 3.2 7.9 3.2 7.7 2.7 CULVERT N 435,089 1,150,240 5.6 1.0 5.6 1.0 * * CULVERT INSIDE 435,086 1,150,204 4.7 0.9 4.7 0.9 * * CULVERT S 435,070 1,150,128 3.7 0.8 3.7 0.8 * *

MISC. LOCATIONS:

FOOTBRIDGE 439,199 1,150,681 8.3 * 8.3 * 8.3 * MANATEE AV 439,307 1,150,177 8.3 * 8.3 * 8.3 * MAIN CHANNEL 432,081 1,145,973 * * * * * * PERICO BAYOU 435,137 1,156,360 * * * * * * ROOKERY OUTSIDE 438,323 1,152,539 8.0 * 8.0 * 8.0 *

NOTE: *Concentration never exceeds 1% or 10% at these locations.

58 COASTAL PLANNING & ENGINEERING, INC.

Typical Flood

Typical Ebb

Figure 43: Increases (+greens) or Decreases (-reds) in Current Speed Given the Construction of Alternative 2.

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Figure 44: Typical Spring-Tide Flood Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 3.

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Figure 45: Typical Spring-Tide Ebb Currents under Average Conditions Given the No Action Scenario (Alternative 1) and Alternative 3.

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Typical Flood

Typical Ebb

Figure 46: Increases (+greens) or Decreases (-reds) in Current Speed Given the Construction of Alternative 3.

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Figure 47: Simulated Currents in the Culvert Interior under Average Conditions Given Alternatives 1 and 3.

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Figure 48: Simulated Currents outside the South End of the Culvert under Average Conditions Given Alternatives 1 and 3.

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Figure 49: Simulated Currents under the Manatee Avenue Bridge under Average Conditions Given Alternatives 1 and 3.

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Figure 50: Simulated Currents within the Mosquito Ditch and Flushing Channels under Average Conditions Given Alternative 3 as Compared to the Critical Velocity for Sediment Mobility.

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Figure 51: Simulated Currents within the Culvert Interior under Average Conditions as Compared to the Critical Velocity for Sediment Mobility.

67 COASTAL PLANNING & ENGINEERING, INC.

7. CONCLUSIONS

Using the Delft3D-FLOW model, tidal flushing was evaluated in Perico Bayou, Spoonbill Bay, and the main pond to be constructed as part of the Perico Preserve Habitat Restoration. Calibration of the model was conducted using water levels collected in June 2012, which were characterized by heavy rains. To examine tidal flushing over more typical conditions, tidal flushing patterns given the existing conditions, the preliminary project design, and the most recent project design were evaluated using water levels from an earlier period characterized by average weather conditions. Overall, the findings of the tidal flushing evaluations were the following:

 Overall, the main conduits for the flushing of the Habitat Restoration’s main pond will be the two cuts connecting it to Perico Bayou.

68 COASTAL PLANNING & ENGINEERING, INC.

8. REFERENCES

Coastal Planning & Engineering, Inc., 2010. 2009 Third-Year Annual Post-Construction Monitoring Report for Anna Maria Island, Manatee County, Florida, Coastal Planning & Engineering, Inc., Boca Raton, Florida.

Coastal Planning & Engineering, Inc., 2010. 2009 Lido Key Beach Renourishment Project, 2- Year Post-Construction Engineering Monitoring Report, Coastal Planning & Engineering, Inc., Boca Raton, Florida.

Coastal Planning & Engineering, Inc., 2012. 2005–2006 Longboat Key Beach Nourishment Project, 2011 Annual Beach Survey and Analysis, Coastal Planning & Engineering, Inc., Boca Raton, Florida.

Deltares, 2010. SuperTrans Manual - OpenEarth - Deltares Wiki, http://publicwiki.deltares.nl/display/OET/SuperTrans+manual.

Deltares, 2011. Delft3D-FLOW, Simulation of Multi-Dimensional Hydrodynamic Flows and Transport Phenomena, Including Sediments, User Manual, Part of Hydro- Morphodynamics, Deltares, Rotterdam, Netherlands.

Flater, D., Pentcheff, D., 2009. WWW Tide and Current Predictor, http://tbone.biol.sc.edu/tide/.

Florida Department of Environmental Protection, 2003. LABINS Mean High Water Interactive Map, Florida Department of Environmental Protection, Tallahassee, FL, http://data.labins.org/imf3/IMHW3/imfStyle2.jsp.

Florida Department of Environmental Protection, 2005. Sarasota 2005 DEP Ground Survey, Florida Department of Environmental Protection, Tallahassee, FL, ftp://ftp.dep.state.fl.us/pub/water/beaches/HSSD/ProfileData/prof839088/SAPZ.ZIP/ COUNTYWIDE(R1-R183)/ST0507_CON_1.PRF.

Florida Department of Environmental Protection, 2012. Land Boundary Information System, High-Resolution Images, Florida Department of Environmental Protection, Tallahassee, FL, http://data.labins.org/2003/MappingData/DOQQ/hi-res_index.cfm.

Florida Division of Emergency Management, 2007. 2004 - 2008 Florida Division of Emergency Management (FDEM) Lidar Project: Southwest Florida, Florida Division of Emergency Management, Tallahassee, FL, http://www.csc.noaa.gov/digitalcoast/data/coastallidar.

Florida Fish and Wildlife Conservation Commission, 2011. Seagrass Florida Vector Digital Data, Florida Fish and Wildlife Conservation Commission, Tallahassee, FL, http://ocean.floridamarine.org/mrgis/Description_Layers_Marine.htm.

69 COASTAL PLANNING & ENGINEERING, INC.

GeoCommunity, 2004. GIS Data Catalog, MindSites Group, Niceville, FL, http://data.geocomm.com/catalog/index.html.

Google, 2012. Google Earth, Google, Mountain View, CA, http://www.google.com/earth/index.html.

National Oceanographic and Atmospheric Administation, 2006. GEODAS Grid Translator - Design-a-Grid, NOAA National Geophysical Data Center, U.S. Coastal Relief Model, National Oceanographic and Atmospheric Administation, Silver Spring, MD, http://www.ngdc.noaa.gov/mgg/gdas/gd_designagrid.html.

National Oceanographic and Atmospheric Administration, 2010. Vertical Datum Transformation, Welcome to VDATUM, National Oceanographic and Atmospheric Administation, Silver Spring, MD, http://vdatum.noaa.gov/.

National Oceanographic and Atmospheric Administation, 2012. NOAA Tides & Currents, Center for Operational Oceanographic Products and Services, National Oceanographic and Atmospheric Administation, Silver Spring, MD, http://tidesandcurrents.noaa.gov/index.shtml.

National Oceanographic and Atmospheric Administation, 2012. NOS Hydrographic Survey Data, National Oceanographic and Atmospheric Administation, Silver Spring, MD, http://www.ngdc.noaa.gov/mgg/bathymetry/hydro.html.

Stantec, 2012. Construction Plans for the Rookery at Perico Preserve, Stantec, WillsonMiller, Inc., Sarasota, FL.

Stantec, 2012. Survey drawing dated September 2012, Stantec, WillsonMiller, Inc., Sarasota, FL.

U.S. Army Corps of Engineers, 2010. Corpscon Verison 6.0, U.S. Army Corps of Engineers Army Geospatial Center, Washington, DC, http://www.agc.army.mil/corpscon/.

U.S. Army Corps of Engineers, 2010. 2010 US Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) Lidar: Gulf Coast of Florida, U.S. Army Corps of Engineers, Mobile, AL, http://www.csc.noaa.gov/digitalcoast/data/coastallidar.

U.S. Army Corps of Engineers, 2010. Longboat Pass, Manatee County, Florida Examination Survey FY11, Surveying & Mapping Branch, Hydrographic Surveys, U.S. Army Corps of Engineers, Jacksonville, FL, http://www.saj.usace.army.mil/Divisions/Operations/Branches/SurveyMap/hydro.htm.

70 COASTAL PLANNING & ENGINEERING, INC.

U.S. Army Corps of Engineers, 2010. New Pass, Sarasota County, Florida Project Condition Survey, Sarasota, FY10, Surveying & Mapping Branch, Hydrographic Surveys, U.S. Army Corps of Engineers, Jacksonville, FL, http://www.saj.usace.army.mil/Divisions/Operations/Branches/SurveyMap/hydro.htm.

U.S. Geological Survey, 2012. Tampa Bay Topographic/Bathymetric DEM, U.S. Geological Survey, Reston, VA, http://gulfsci.usgs.gov/tampabay/index.html and http://dl.cr.usgs.gov/net_prod_download/public/gom_net_pub_products/data_spa/tampa_ dem.zip.

U.S. Geological Survey, 2012. USGS 273126082384700 Manatee River near Mouth at Palma Sola, FL, U.S. Geological Survey, Reston, VA, http://waterdata.usgs.gov/nwis/inventory?agency_code=USGS&site_no=2731260823847 00.

University of South Florida, 2012. Coastal Ocean Monitoring & Prediction System, University of South Florida, Tampa, FL, http://comps.marine.usf.edu/.

Vanoni, V.A., ed., 1975. Sedimentation Engineering, ASCE Task Committee for the Preparation of the Manual on Sedimentation of the Sedimentation Committee of the Hydraulics Division (reprinted 1977).

Weather Underground, 2012. Welcome to Weather Underground, Atlanta, GA, http://www.wunderground.com/.

P:\Manatee\146161_Perico_Preserve\Report\Perico Preserve Habitat Restoration Modeling Study_revised.doc

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ROOKERY AT PERICO SEAGRASS ADVANCE MITIGATION Appendix B Attachments May 17, 2013

B.2 UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PARTS I AND II

Seagrass Habitat Creation Credits – Patchy (Pages 1 - 2) Seagrass Habitat Creation Credits – Continuous (Pages 3 - 4) Mangrove Habitat Creation Credits (Pages 5 -6)

rh \\us1227-f01\workgroup\2155\active\215510428\env\05_rpt-deliv\deliverables\swfwmd\submittal_final\rpt_mitigation_credits_20130516_final.docx B.2 UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART I - MIT/PRES Form 62-345.900(2), F.A.C. (See Sections 62-345.400 F.A.C.)

Site/Project Name Application Number Assessment Area Name or Number

The Rookery at Perico Seagrass Advance Mitigation Seagrass Creation Area (patchy)

FLUCCs code Further classification (optional) Mitigation or Preservation? Assessment Area Size 911 - Seagrass NWI: E2AB (Estuarine Intertidal Aquatic Bed) mitigation Acres

Basin/Watershed Name/Number Affected Waterbody (Class) Special Classification (i.e.OFW, AP, other local/state/federal designation of importance) Sarasota/Lemon Bay Drainage Geographic relationship to and hydrologic connection with wetlands, other surface water, uplands The Seagrass Creation Area will be surrounded by restored upland and wetland habitats on the north, south, and west. On the east, the area will abut existing mangrove forest and have two excavated tidal connections to Perico Bayou. The tidal connections were designed to mimic the tidal regime within Perico Bayou. Assessment area description The assessment area includes fallow farm fields excavated to -2 feet NAVD and tidally connected to Perico Bayou through two flushing channels. The area will be vegetated with seagrass (H. wrightii , T. testudinum , S. filiforme ) through natural recruitment, seagrass unit transplanting from adjacent donor, or a combination of both. A bird rookery will be constructed to promote roosting and nesting wading birds. Uniqueness (considering the relative rarity in relation to the regional Significant nearby features landscape.) The seagrass habitat will not be unique; however, the Perico Bayou, Palma Sola Bay, Manatee River, Perico Preserve conversion of fallow farmland to seagrass habitat will be unique. Functions Mitigation for previous permit/other historic use Water quality improvement, wildlife shelter and nursery habitat, No wildlife food source, detrital input Anticipated Wildlife Utilization Based on Literature Review (List of species Anticipated Utilization by Listed Species (List species, their legal that are representative of the assessment area and reasonably expected to classification (E, T, SSC), type of use, and intensity of use of the be found ) assessment area)

Finfish, including snook, redfish, snapper, spotted sea trout, flounder, mullet, and many other fish species common to local waters. Crabs, stingrays, oysters, pink shrimp, and various crustaceans and mollusks common to local West Indian manatee; listed wading birds waters. West Indian manatee. Wading and diving birds, including wood storks, ducks, cormorants, great egrets, and pelicans. Observed Evidence of Wildlife Utilization (List species directly observed, or other signs such as tracks, droppings, casings, nests, etc.):

N/A

Additional relevant factors:

This UMAM designates the RFG that shall be applied to the areas delineated as "patchy seagrass". For additional details, please refer to the "Rookery at Perico Seagrass Advance Mitigation - Mitigation Establishment Criteria Report".

Assessment conducted by: Assessment date(s): Ryan Horstman 2/13/2013

Form 62-345.900(1), F.A.C. [ effective date ]

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_seagrass_20130429_patchy_v1.xls UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART II - MITIGATION/PRESERVATION Form 62-345.900(2), F.A.C. (See Sections 62-345.500 and .600, F.A.C.)

Site/Project Name: Application Number: Assessment Area Name or Number: The Rookery at Perico Seagrass Advance Mitigation - Seagrass Creation Area (patchy) Impact or Mitigation: Assessment Conducted by: Assessment Date: mitigation Ryan Horstman 2/13/13

Scoring Guidance Optimal (10) Moderate(7) Minimal (4) Not Present (0)

The scoring of each indicator is based on what Condition is optimal and fully Condition is less than optimal, but sufficient to Minimal level of support of Condition is insufficient to provide would be suitable for the type of wetland or supports wetland/surface water maintain most wetland/surface waterfunctions wetland/surface water functions wetland/surface water functions surface water assessed functions

a. Quality and quantity of habitat support outside of AA. b. Invasive plant species. c. Wildlife access to and from AA (proximity and barriers). .500(6)(a) Location and Landscape Support d. Downstream benefits provided to fish and wildlife. e. Adverse impacts to wildlife in AA from land uses outside of AA. f. Hydrologic connectivity (impediments and flow restrictions). g. Dependency of downstream habitats on quantity or quality of discharges. Current With Mitigation h. Protection of wetland functions provided by uplands (upland AAs only). Seagrass creation area will be surrounded by compatible land uses and habitats that will mutually benefit from the adjacent habitats. The creation area will provide downstream benefits through water quality improvement and provision of additional suitable habitat for species 09Notes: utilizing downstream habitats. No impediments to wildlife access exist between the creation area and adjacent habitats. The tidal connections will provide sufficient hydrologic connection without flow impediments or impediments to wildlife mobility.

a. Appropriateness of water levels and flows. b. Reliability of water level indicators. c. Appropriateness of soil moisture. d. Flow rates/points of discharge. .500(6)(b)Water Environment (n/a for uplands) e. Fire frequency/severity. f. Type of vegetation. g. Hydrologic stress on vegetation. h. Use by animals with hydrologic requirements. i. Plant community composition associated with water quality (i.e., plants tolerant of poor WQ). j. Water quality of standing water by observation (I.e., discoloration, turbidity). k. Water quality data for the type of community. Current With Mitigation l. Water depth, wave energy, and currents. The seagrass creation area will be excavated to -2 feet NAVD, which corresponds to elevations within Perico Bayou that currently support continuous seagrass cover. The tidal regime will provide sufficient flushing to maintain good water quality that is similar to Perico Bayou. 0 9 Notes:

I. Extent, diversity of appropriate species and organisms .500(6)(c)Community structure II. Invasive/exotic species III. Regeneration, recruitment, age distribution Vegetation IV. Species' condition, biomass V. Structural features X Benthic VI. Topographic features VII. Spawning, nesting habitat Both ------Current With Mitigation Seagrass creation area will support patchy cover by Halodule wrightii , Thalassia testudinum , Syringodium filiforme , or a combination of both species. Other species such as Halophila species may also be present. Motorized vessels will be prohibited from operating within the creation Notes: area. The score acknowledges the potential that the patchy seagrass cover is less stable or not fully developed. This accounts for seasonal 0 8 variation in seagrass cover or seagrass migration that may affect the total cover by seagrass within the habitat.

Relative Functional Gain (RFG) = 0.870 Raw Score = Sum of above scores/30 (if MD/(TLF x RF) = uplands, divide by 20) Mitigation Area Required (acres) = N/A FL/RFG =

Current With Mitigation

Temporal Lag Factor (TLF) = (see 1.00 Mitigation Area Size (acres) TBD Temporal Lag Table above) 0.00 0.87 Risk Factor (RF) = Functional Gain (FG) (RFG x MIT AREA) 1.00 TBD [1=no risk, 2=mod risk, 3=hi risk, on 0.25 increments) (should balance with Functional Loss)

FOR PRESERVATION ONLY:

Mitigation Delta (MD) Excess Mitigation (acres) N/A

Acres of Impact Offset by this Mitigation w/Mitigation - Current 0.87 N/A Area

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_seagrass_20130429_patchy_v1.xls UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART I - MIT/PRES Form 62-345.900(2), F.A.C. (See Sections 62-345.400 F.A.C.)

Site/Project Name Application Number Assessment Area Name or Number

The Rookery at Perico Seagrass Advance Mitigation Seagrass Creation Area (continuous)

FLUCCs code Further classification (optional) Mitigation or Preservation? Assessment Area Size 911 - Seagrass NWI: E2AB (Estuarine Intertidal Aquatic Bed) mitigation Acres

N/A

Additional relevant factors:

This UMAM designates the RFG that shall be applied to the areas delineated as "continuous seagrass".For additional details, please refer to the "Rookery at Perico Seagrass Advance Mitigation - Mitigation Establishment Criteria Report".

Assessment conducted by: Assessment date(s): Ryan Horstman 2/13/2013

Form 62-345.900(1), F.A.C. [ effective date ]

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_seagrass_20130429_continuous_v1.xls UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART II - MITIGATION/PRESERVATION Form 62-345.900(2), F.A.C. (See Sections 62-345.500 and .600, F.A.C.)

Site/Project Name: Application Number: Assessment Area Name or Number: The Rookery at Perico Seagrass Advance Mitigation - Seagrass Creation Area (continuous) Impact or Mitigation: Assessment Conducted by: Assessment Date: mitigation Ryan Horstman 2/13/13

Scoring Guidance Optimal (10) Moderate(7) Minimal (4) Not Present (0)

I. Extent, diversity of appropriate species and organisms .500(6)(c)Community structure II. Invasive/exotic species III. Regeneration, recruitment, age distribution Vegetation IV. Species' condition, biomass V. Structural features X Benthic VI. Topographic features VII. Spawning, nesting habitat Both ------Current With Mitigation Seagrass creation area will support patchy cover by Halodule wrightii , Thalassia testudinum , Syringodium filiforme , or a combination of both species. Other species such as Halophila species may also be present. Motorized vessels will be prohibited from operating within the creation Notes: area. The score represents the development of dense, continuous seagrass cover with high biomass. 0 9

Relative Functional Gain (RFG) = 0.900 Raw Score = Sum of above scores/30 (if MD/(TLF x RF) = uplands, divide by 20) Mitigation Area Required (acres) = N/A FL/RFG =

Current With Mitigation

Temporal Lag Factor (TLF) = (see 1.00 Mitigation Area Size (acres) TBD Temporal Lag Table above) 0.00 0.90 Risk Factor (RF) = Functional Gain (FG) (RFG x MIT AREA) 1.00 TBD [1=no risk, 2=mod risk, 3=hi risk, on 0.25 increments) (should balance with Functional Loss)

FOR PRESERVATION ONLY:

Mitigation Delta (MD) Excess Mitigation (acres) N/A

Acres of Impact Offset by this Mitigation w/Mitigation - Current 0.90 N/A Area

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_seagrass_20130429_continuous_v1.xls UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART I - MIT/PRES Form 62-345.900(2), F.A.C. (See Sections 62-345.400 F.A.C.)

Site/Project Name Application Number Assessment Area Name or Number

The Rookery at Perico Seagrass Advance Mitigation Mangrove Creation

FLUCCs code Further classification (optional) Mitigation or Preservation? Assessment Area Size NWI: E2SS3P (Estuarine Intertidal Scrub-shrub 612 - Mangrove Swamp mitigation Acres Broad-leaved evergreen)

Mangrove creation areas will be directly connected to constructed tidal seagrass basin and adjacent to restored uplands and wetlands. Rookery Island planting zone will be surrounded by tidal basin.

Assessment area description The assessment areas include created mangrove forest habitat located along the slope of a created tidal seagrass creation basin and around the Rookery Isand. The basin slope assessment area is a linear fringe along the created 10:1 slope with tidal waters downslope and restored uplands on the upslope side. Uniqueness (considering the relative rarity in relation to the regional Significant nearby features landscape.) Restored upland and wetland habitats including the large tidal basin. Not unique in the region. Perico Bayou is immediately to the east. Functions Mitigation for previous permit/other historic use Erosion protection, surface water filtration, nursery habitat, wildlife No corridor. Anticipated Wildlife Utilization Based on Literature Review (List of species Anticipated Utilization by Listed Species (List species, their legal that are representative of the assessment area and reasonably expected to classification (E, T, SSC), type of use, and intensity of use of the be found ) assessment area)

Wading bird roosting and forage, small mammal forage, Both endangered and threatened wading birds common to the amphibians/reptiles, fish nursery. Rookery Island designed to provide area are likely to roost in the mangroves and forage adjacent to a bird rookery protected by the seagrass basin with an interior forage the mangroves. area.

Observed Evidence of Wildlife Utilization (List species directly observed, or other signs such as tracks, droppings, casings, nests, etc.):

N/A

Additional relevant factors:

Native vegetation and sod will be installed upslope from along basin slope to prevent erosion. Areas will be vegetated with mangroves through natural recruitment and planting. The basin slope assessment area is between one-foot below and one-foot above the Mean High Water (0.33 ft NAVD88). The Rookery Island planting zone is at 0.20 feet NAVD.

Assessment conducted by: Assessment date(s): Ryan Horstman 4/23/2013

Form 62-345.900(1), F.A.C. [ effective date ]

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_mangrove_creation_20130423.xls UNIFORM WETLAND MITIGATION ASSESSMENT WORKSHEET - PART II - MITIGATION/PRESERVATION Form 62-345.900(2), F.A.C. (See Sections 62-345.500 and .600, F.A.C.)

Site/Project Name: Application Number: Assessment Area Name or Number: The Rookery at Perico Seagrass Advance Mitigation - Mangrove Creation Impact or Mitigation: Assessment Conducted by: Assessment Date: mitigation Ryan Horstman 4/23/13

Scoring Guidance Optimal (10) Moderate(7) Minimal (4) Not Present (0)

a. Quality and quantity of habitat support outside of AA. b. Invasive plant species. c. Wildlife access to and from AA (proximity and barriers). .500(6)(a) Location and Landscape Support d. Downstream benefits provided to fish and wildlife. e. Adverse impacts to wildlife in AA from land uses outside of AA. f. Hydrologic connectivity (impediments and flow restrictions). g. Dependency of downstream habitats on quantity or quality of discharges. Current With Mitigation h. Protection of wetland functions provided by uplands (upland AAs only). The mangrove creation areas will provide a forested fringe between the tidal basin and restored upland habitats. The Rookery Island planting zone will provide a protected rookery for bird roosting and nesting. Events will be conducted to control the establishment of invasive plant 08Notes: species. The mangroves will provide habitat for aquatic species using the tidal basin and Perico Bayou and roosting habitat for avian species. Adjacent land use complements the mangrove creation areas.

a. Appropriateness of water levels and flows. b. Reliability of water level indicators. c. Appropriateness of soil moisture. d. Flow rates/points of discharge. .500(6)(b)Water Environment (n/a for uplands) e. Fire frequency/severity. f. Type of vegetation. g. Hydrologic stress on vegetation. h. Use by animals with hydrologic requirements. i. Plant community composition associated with water quality (i.e., plants tolerant of poor WQ). j. Water quality of standing water by observation (I.e., discoloration, turbidity). k. Water quality data for the type of community. Current With Mitigation l. Water depth, wave energy, and currents. The elevations at which the mitigation area will be established correspond to mean high water and elevations of existing mangroves. The tidal connections will allow the hydrologic regime within the tidal basin to mimic Perico Bayou, thus providing adequate hydrology and water quality. 0 8 Notes:

I. Appropriate/desirable species .500(6)(c)Community structure II. Invasive/exotic plant species III. Regeneration/recruitment x Vegetation IV. Age, size distribution. V. Snags, dens, cavity, etc. Benthic VI. Plants' condition. VII. Land management practices. Both VIII. Topographic features (refugia, channels, hummocks). IX. Submerged vegetation (only score if present). X. Upland assessment area Current With Mitigation The mangrove creation areas will be vegetated through natural recruitment and planting. Events will be conducted to control the establishment of invasive plant species. The mangrove creation areas will provide conditions that support mangrove recruitment and regenration. Notes: 0 8

Relative Functional Gain (RFG) = 0.800 Raw Score = Sum of above scores/30 (if MD/(TLF x RF) = uplands, divide by 20) Mitigation Area Required (acres) = N/A FL/RFG =

Current With Mitigation

Temporal Lag Factor (TLF) = (see 1.00 Mitigation Area Size (acres) N/A Temporal Lag Table above) 0.00 0.80 Risk Factor (RF) = Functional Gain (FG) (RFG x MIT AREA) 1.00 TBD [1=no risk, 2=mod risk, 3=hi risk, on 0.25 increments) (should balance with Functional Loss)

FOR PRESERVATION ONLY:

Mitigation Delta (MD) Excess Mitigation (acres) N/A

Acres of Impact Offset by this Mitigation w/Mitigation - Current 0.80 N/A Area

\\us1227-f01\workgroup\2155\active\215510428\env\03_data\work_UMAM_mangrove_creation_20130423.xls