North Spreader Canal Ecosystem Management Agreement Process

Meeting 5

S. FL Water Management District, Ft. Myers

2301 McGregor Blvd.

Fort Myers, FL 33990

October 29, 2008

Meeting Call in number Nationwide Toll Free 866-433-6299 Meeting ID: 2737

(First caller should let the phone ring until another joins)

 

Objectives

 

 

Agenda

 

  8:30   Welcome and Introductions

 

  8:45   A Methodology for Understanding the Canal and Receiving Waters

Present and discuss the box modeling approach

Explain how it considers freshwater and tidal flows, bank openings and barrier

General questions and answers

Review of Survey Scope and Approach

Review and explain scope and approach

Answer questions for clarification

 

  9:15   The Barrier Replacement Decision Making

Clarify project options:

Spreader canal and bank options

                  No action (allow current breaches to remain)

                  Additional and/or modified openings

                  Control structures, etc.

                  Permanent spreader (structural wall)

Others?

If there are new openings, where should they be?

            Evenly spaced to distribute flows

            Where historic tidal creeks were located

            Where water is needed to reduce growth of exotics

Barrier options

                  Barrier replacement with completion of permitted projects

                  No barrier with permitted and new projects 

                  Barrier replacement with permitted and new projects

Summarize how the box model and information will be used in evaluating options

 

10:30   Break


10:45   The Receiving Wetlands and Waters

Performance measures -- Present the Habitat Suitability Index methodology

      Explain HSI modeling procedures

      Suggest indicator species

      Explain how the HSIs can be used to determine salinity and fresh water flows

      Test acceptability of the proposed approach

Projects -- Recap possible types of projects within the wetlands and receiving waters

      Modifying existing mosquito ditches and canals

      Redirect water flows

      Weirs

      Others?

Summarize information that will be provided by the box model and the relationship of that information to the HSI and the proposed surveying

     

12:00   Lunch

 

  1:15   The Barrier Replacement Decision Making (continued)

      Initial discussion of pros and cons of replacing the barrier – “What are you afraid of?”

      Review and refine pros and cons generated by Technical Team

      Identify additional pros and cons

      Discuss and clarify the nature uses of the list

Possible steps in decision-making (refer to the work plan)

      Provide flow and timing analysis of options using the box model

      Develop a proposal for water quality analysis of options in the receiving waters

      Develop a proposal for discussing whether to assess secondary impacts

      Review initial flow results and analysis proposals in January

      Review flow and timing, quality and boating analysis results in February

      Decision on barrier replacement in March

 

  2:15   Break

 

  2:30   NEB Discussion

Review revised NEB worksheet

Consider additional input from DEP

Finalize (ideally) discussion of projects eligible to have their impacts considered in the calculation of NEB

 

  3:30   Review Revised Work Plan and Next Steps (consider draft 12-12 agenda)

 

  4:45   Adjourn

 


 

City of Cape Coral – North Spreader Canal

Field Survey Scope of Work – DRAFT (rev1)

 

1.       Introduction

The City of Cape Coral (City) wishes to engage a firm for the purpose of obtaining new field survey data for the North Spreader Canal (NSC). The NSC is located along the east shore of Matlacha Pass and extends from Pine Island Road (SR 78) north a distance of approximately seven miles to a point near the west end of Caloosa Parkway (Figure 1). The data will be used to characterize existing conditions along the west bank of the canal to assist in hydrologic modeling of the canal and tributary stormwater system. Cost proposals for this work should include separate costs for Part 1 and Part 2 below.

 

2.       Scope of Work

Point data will be obtained at specified locations along the west bank of the NSC. The overall intent is to gain a general understanding of the current elevation of the existing NSC west top of bank (TOB), and also to obtain more detailed information regarding the geometry of the breaches that have developed as described below. Because future work using these data will require referencing vertical elevations to tide stage, the date and time of all measurements shall be recorded.

 

PART 1

 

2.1     NSC West Top of Bank

Using GPS equipment and methods acceptable to the City, spot elevations will be taken along the NSC west bank as follows:

-        A detailed survey of the NSC west bank was completed in 1993 by Avalon Engineering. It is desired to verify that top of bank elevations taken at that time are still generally adequate for modeling. A baseline will be established generally following the 1993 baseline. Spot elevations (15 minimum) will include the north and south ends of the baseline and the entire bank length between. The spot elevations will be distributed so that eight are taken in the north one-third of the NSC, and the remaining seven along the southern two-thirds.  

-        Vertical elevations shall be based on the location of consolidated material, and will not include soft sediments, mangrove roots or organic mulch.

-        Coordinates for x, y, and z locations will be made at each site such that the spot locations can be transferred to suitable mapping software (e.g. GIS).

-        The TOB elevation height above water level shall be recorded at each site.

 

2.2     Bank Breaches

A detailed survey of breaches in the NSC west bank was completed in 1993. A visual inspection and documentation of breaches in the west NSC bank was conducted by City of Cape Coral staff in June 2008.  Survey completed under this scope will update the width and depth of some of the major breaches as identified by the Cape Coral field work, specifically, breaches 1A and 4 as identified in Figure 2.  Detailed x, y, and z data are required at selected breaches as follows:

-        A minimum of five x, y, and z measurements will be taken at each surveyed breach. These measurements will include north and south TOB, north and south breach toe of slope (TOS), and the breach low point (invert elevation – IE) within the breach. Additional measurements should be taken if the site has complex geometry.

-        The water level elevation at each breach will be recorded at the time of survey measurement.

-        Vertical elevations shall be based on the location of consolidated material, and will not include soft sediments, mangrove roots or organic mulch.

-        If additional breaches not identified during previous field reconnaissance are encountered, those breaches should be documented in the same manner.

-        At least one digital photograph will be taken of each breach. A physical object indicating visible one foot increments should be included in the photo for general reference of scale as feasible.

 

PART 2

 

2.3     Point Elevations West of the NSC

Six spot elevations will be established on uplands located west of the NSC west bank. Specific locations for these spots will be established by the City in coordination with the surveyor. The purpose of these data is to generally characterize the land surface between the NSC and Matlacha Pass. In general, survey locations will include topographic highs as identified by visual inspection of aerial photographs and potentially field reconnaissance. X, y, and z coordinates will be taken to the standards listed within this Scope of Work. This work element is optional and should be costed out separately from Part 1.

 

3.       Assumptions

3.1     All data will be collected using GPS equipment and methods, including projections that are acceptable to the City and consistent with City survey standards. All GPS coordinate data will be referenced to the Florida State Plane Coordinate System, West Zone 902, NAD 1983/1990 Adjustment, U.S. Survey Foot.

3.2     All vertical data will be referenced to NGVD 1929 datum.

3.3     Results will be provided to the City in electronic and hard copy format. Electronic format will include coordinates and projections suitable for geo-locating all data collection sites. The digital coordinate data will be in the classic format; Point Number, Northing, Easting, Elevation, and Description (PNEZD).

3.4     Elevations will be based on the level of consolidated material and will not include loose organic muck and detritus.

3.5     The data and time of all measurements shall be recorded.


Pros and Cons of Putting the Barrier Back

 

The following items were identified by the Technical Committee as a starter list for further consideration by the Stakeholder Committee.  It is important to note that the list describes either member’s concerns, or concerns that members believe to be held by others, without regard to the factual basis of the concern. 

 

The purpose of the list is to identify issues that should be addressed through information gathering and analysis as the impacts of projects, and particularly of replacing or not replacing the barrier, are evaluated.

 

Possible Pros

 

1.     Decrease potential boat traffic

2.     Decrease fresh water flow to Matlacha pass

3.     Increase water flow to other areas along the spreader

4.     It would increase the hydro period

5.     It would keep areas to the west wet

6.     Reduce saltwater intrusion in areas to the East

7.     Reduces residential development

8.     Increases reuse water for Cape Coral

9.     Fewer boats may protect water quality

10. Increase the habitat for fisheries

11. Reduces demand for dredging in Matlacha Pass

12. Improve stormwater treatment

 

Possible Cons

 

1.     Replacement money could be used for other projects

2.     There would be less incentive to solve a regional problem

3.     There will be no NEBs

4.     Erosion on the west side and habitat damage

5.     Accelerates the need for central sewage and

6.     Increased saline habitat

7.     Continued maintenance problems

8.     Sea level rise will make this moot

 


NEB Worksheet

 

 

Definition of Net Ecosystem Benefit (NEB) 

 

A package of positive environmental impacts constitutes an NEB if they exceed the benefits that would be obtained through conventional enforcement action.  The Consent Order governing the NS-EMA process defines the conventional enforcement action in this case as replacement of the barrier. 

 

Character of NEB Benefits 

 

To count toward NEB for purposes of this process, environmental benefits must be related to improvements, measured by adopted performance measures, in the volume, timing, distribution or quality of water.  Other, non-water related environmental benefits of NEB projects will noted in the report, but will not be counted toward the calculation of NEB.

 

Threshold for NEB

 

The threshold above which a package of positive environmental impacts constitutes a NEB is the projected quantity, timing and quality of water that would exist if the barrier is replaced, currently permitted projects completed, and expected future development materializes.  Both a short-term and a longer-term threshold will be calculated.  (Exact time horizons still to be determined.)

 

Location of NEB Projects and Benefits: 

 

To count toward NEB for purposes of this process, projects and their resulting environmental benefits must be located:

 

·       In the current or historic watershed of the north spreader canal;

·       In or on the banks of the spreader canal itself or associated feeder canals;

·       In the receiving wetlands or waters of the Aquatic Preserve or Matlacha Pass.

 

Timing of NEB and Non-NEB Projects 

 

Projects that are currently permitted (except the subsequent phases of multi-phase projects as described below), will have their impacts included in the threshold.

 

On-going multi-phase or multi-year projects may have the impacts of their subsequent phases included in the calculation of the threshold or of the NEB, to be decided by the Stakeholder group on a case-by-case basis.

 

All other currently planned or new projects will eligible to have their impacts included in the calculation of NEB.

 


NS-EMA Work Plan

 

D R A F T

 

Please note:  This workplan is intended as general guide to the sequence of tasks to be undertaken by the Stakeholder Group and the Technical Committee.  It will be refined and updated to reflect actual events and developments in the process on a regular basis.

 

July 8, 2008– Organizational Meeting

 

August 7, 2008 – Natural Systems and hydrology

 

September 12, 2008 – Natural Systems and hydrology (continued), Water Quantity and Quality

 

October 29, 2008 – Targets/Performance Measures, Project Evaluation and Modeling Methodology, and Initial Discussion of Project List


November – Review and Refinement of Project List

 

December – Establishing the NEB Threshold and Water Budget, Further Review and Refinement of Project List

 

January -- Project Impacts and Prioritization

 

February – Project Impacts and Prioritization

 

March  -- Nine Month Decision

 

April – Initial Discussion of Recommendations

 

May - Draft Report

 

June – Final Consensus Seeking and Decision on the Report

Final decision to adopt the report or require construction of the barrier and boat lift