 Prepared by  Prepared for  City of Palm Coast, Florida  August 30, 2011  Drainage Study Sections 31 & 35/37 for Development of City Wide Stormwater Management Master Plan

Singhofen & Associates, Inc.August 2011  May 2009 Storm Event  Rainfall totals range = 20 – 25 inches  Rainfall ~ 300 Year – 5 Day storm  Bird of Paradise Area (Section 35) :  High water reported near homes at 3 locations  Measured water elevations validate model simulations (simulated elevations within 0.1 feet of measured values)  Measured high water elevations equate to 25 or 50 Year - 24 Hour storm condition  Rymfire Ditch Area (Section 31) :  Roadway overtopping reported at approximately 5 locations  Model confirms storm conditions Study Findings

Singhofen & Associates, Inc.August 2011  System Performance Evaluation For Ditches & Canals:  Service Level A: Flow is contained within the system (i.e., no flooding of major roadways, minor roadways, yards or buildings occurs)  Service Level B: Flow is contained within the right of way (i.e., flooding is limited to the outer lane of major roadways and right-of-way area of yards)  Service Level C: Flooding of minor streets precludes travel and flooding of yards is at the buildings but no structure flooding occurs.  Service Level D: Extensive flooding of yards including buildings.  Note: Level of Service Objective = “B”  Level “C” is considered deficient  Level “D” is considered unacceptable Level of Service Evaluations

Singhofen & Associates, Inc.August 2011  System Performance Evaluation For Homes:  Home flooding evaluated relative to base flood (i.e., 100-year storm)  City code requires 1 foot of freeboard above 100-year elevation Level of Service Evaluations Freeboard

Singhofen & Associates, Inc.August 2011 Section 31 (“R” Section) – Level of Service

Singhofen & Associates, Inc.August 2011  Section 31  High water levels due to:  Constrictions at Royal Palms Pkwy, school & park driveways  Low ground elevations in “R” Section relative to Royal Palms Pkwy and Rymfire Drive  No home flooding predicted  Number of homes below City standard for 100-year event = 3 %  No secondary drainage deficiencies for 10 year event  Nuisance flooding (2-year) at 5 road crossings Modeling Results

Singhofen & Associates, Inc.August 2011 Section 31 (“R” Section) – Recommended Improvements Culvert replacement and ditch modifications Bypass ditch with outfall to Royal Palms Canal

Singhofen & Associates, Inc.August 2011 Section 35 (“B” Section) – Level of Service Deficient secondary roads = 2 Secondary drainage deficiencies

Singhofen & Associates, Inc.August 2011  Section 35  High water levels due to  Constrictions at London Drive, US 1 (to Hulett Branch)  I-95 (to Mulberry Creek)  Home flooding predicted in < 1 % of homes (all in Bird of Paradise area)  Number of homes below City standard for 100-year event = 11 %  Secondary drainage deficiencies - 10 year event = 2 Modeling Results

Singhofen & Associates, Inc.August 2011 Section 35 (“B” Section) – Recommended Improvements Culvert replacement and ditch modifications

Singhofen & Associates, Inc.August 2011 Section 37 (“L” Section) – Level of Service Deficient secondary roads = 6 Secondary drainage deficiencies

Singhofen & Associates, Inc.August 2011  Section 37  High water levels due to  Constrictions at London Drive, US 1 (to Hulett Branch)  I-95 (to Mulberry Creek)  No home flooding predicted  Number of homes below City standard for 100-year event = 9 %  Secondary drainage deficiencies - 10 year event = 6 Modeling Results

Singhofen & Associates, Inc.August 2011 Section 37 (“L” Section) – Recommended Improvements Culvert replacement and ditch modifications

Singhofen & Associates, Inc.August 2011 Sections 35 & 37 – Recommended Capital Improvements Possible Detention/Reuse Storage Locations 1) ~100-acft required in total 2) Also requires construction of control structures and recovery pump system Excavate existing stream

Singhofen & Associates, Inc.August 2011 Recommended Improvement Plan  Section 31 Improvements:  Ditch and Pipe Modifications (Richardson Drive to Richmond Drive)  Construct Ditch and Pipe under Royal Palms Parkway Cost $194,200 $733,800 $924,000  Level of Service Improvements :  Homes below 100-year City standard reduced by 43 %  Nuisance flooding eliminated Sub-total

Singhofen & Associates, Inc.August 2011 Recommended Improvement Plan  Section 35 Improvements:  Pipe Modifications (Bunker View Drive to Bunker Hill Drive) Cost $159,700  Level of Service Improvements :  Homes below 100-year City standard reduced by 61 %  Roadway deficiencies eliminated Sub-total $159,700

Singhofen & Associates, Inc.August 2011 Recommended Improvement Plan  Section 37 Improvements:  Pipe & Ditch Modifications  Lincoln Lane to Lindsay Drive  Laramie Drive to Lindsay Drive  Laramie Drive to Lynbrook Drive Cost $63,200 $116,600 $184,800  Level of Service Improvements :  Homes below 100-year City standard reduced by 69 %  Roadway deficiencies eliminated Sub-total $364,600

Singhofen & Associates, Inc.August 2011 Recommended Improvement Plan  Section 35 and 37 Improvements:  Ditch Modifications (between Old Kings Road and I-95)  Channel Modifications and Detention Storage Creation Cost $145,800 $3,193,400  Level of Service Improvements :  Homes below 100-year City standard reduced by 63 %  Homes remaining below 100-year City standard = 4 %  All secondary deficiencies eliminated Sub-total $3,339,200

Singhofen & Associates, Inc.August 2011 Recommended Improvement Plan  Summary of All Costs:  Section 31 Improvements  Section 35 Improvements  Section 37 Improvements  Section 35 and 37 Improvements Cost $924,000 $159,700 $364,600 $3,339,200 Grand-Total$4,787,500