HARBOR BAY CDD

EXHIBIT TO 8-17-17 MINUTES:

Langan’s Monitoring Plan for Reconstructed Bulkhead

MIRABAY COMMUNITY DEVELOPMENT

MONITORING PLAN FOR RECONSTRUCTED BULKHEAD

This bulkhead monitoring plan is intended to provide guidelines for general observations and

maintenance for the recently reconstructed bulkheads (“New Walls”) at the Mirabay

Community. The “New Wall” bulkheads were constructed at eastern portions of the Mirabay

waterfront community in 2015 and 2016. The New Wall bulkheads consist of Fiber Reinforced

Polymer (FRP) sheet piles, both existing and new tie back anchors, a larger reinforced concrete

cap enveloping the previous cap, an enhanced drainage system and rip rap waterside berm

placed along a short stretch of the new wall. The New Wall bulkheads were constructed in

accordance with Emergency and Interim Repair construction drawings which are attached to

this guideline document as general reference.

A semi-annual monitoring program is suggested for the New Wall bulkhead. The person or firm

responsible for the bulkhead monitoring program should have a structural and geotechnical

engineering background with experience in seawall construction. The Harbor Bay Community

Development District (HBCDD) or District Manager should develop a log or scheduling protocol

to confirm the monitoring work is consistently performed and to monitor the results. The

monitoring will require site visits and field observations of the New Wall bulkheads in order to

acquire documentation in the form of photographs, field notes and pertinent measurements of

the essential components of the bulkhead. Essential components of the New Wall bulkheads

include: the FRP sheet piles, the concrete cap, the steel tie-back rebar and anchor rods,

drainage materials immediately landside of the bulkhead and rip rap stones (in the isolated

stretch where they were placed immediately against the FRP sheet piles). The responsible

inspecting engineer performing the periodic New Wall bulkhead monitoring should prepare a

written report that summarizes the monitoring observations within 14 days of completing the

field work.

The following lists of items are suggested to be monitored and documented on a semi-annual

basis:

Drainage System

Monitor for unauthorized construction activities that may disturb the upper 3 ft of

subgrade drainage components immediately landside of the bulkhead;

Check for clogged drainage pipes in the concrete cap. These can be easily unclogged

using a garden hose. We suggest that landscapers community-wide be encouraged to

flush the concrete cap drainage holes after each lawn cutting service is performed;

Concrete cap drainage holes should not be obstructed or buried with sod, soil, paver

stones, concrete or any obstruction that prevents surface waters from flowing through

it;

No impervious surfaces should be placed over grassed HBCDD easement areas that lie

between the bulkhead and upland properties.

Check the upper sheet pile weep hole for obstructions.

FRP Sheet Piles

Monitor for unauthorized drilled holes through sheet pile;

Monitor for punctures, dents, fractures, cracks, splits and delamination’s in the material;

Tie Back Anchor System

Monitor the tie-back systems for unauthorized interference (such as unauthorized

construction activities in the HBCDD’s swale easement that may disturb tie-back

systems);

Check a representative sample number of tie-back anchor / cap connections for loss of

steel cross-sectional area as well as the condition of corrosion protection coating. The

frequency of tie-back anchor / cap connection monitoring may be two years, or as

determined by the District Engineer.

Reinforced Concrete Cap

Monitor for unauthorized drilled holes into the concrete surfaces;

Monitor for signs of exposed corrosion;

Monitor the concrete surfaces. The American Concrete Institute (ACI) manuals are

suggested qualitative references for structural concrete.

Rip Rap

For the stretch where rip rap that was placed waterside of the FRP sheet, monitor and

document the toe of rip rap slope; check for rip rap fragments located greater than 8 ft

waterside of the bulkhead. Where present, these fragments could be removed and

placed closer than 8 ft to the wall;

Observe the top of slope at the bulkhead wall. The top of the rip rap should be at or near

el +2 for the stretch where rip rap was placed immediately against the FRP sheet piles.