Environmental Notification Form Crescent Beach Seawall and Revetment Repair Hull, Massachusetts June 30, 2015 Prepared by: Applied Coastal Research and Engineering, Inc. 766 Falmouth Road, Suite A1 Mashpee, Massachusetts 02649 Prepared for: Town of Hull Conservation Department 253 Atlantic Avenue Hull, Massachusetts 02045 Environmental Notification Form Crescent Beach, Hull, MA TABLE OF CONTENTS ENF Distribution List .................................................................................................... iv Environmental Notification Form ................................................................................. v USGS Map ..................................................................................................................... vi 1.0 Project Overview ................................................................................................ 1 1.1 Introduction ....................................................................................................... 1 1.1 Description of Project Area ................................................................................ 1 1.2 Project Area History .......................................................................................... 2 1.3 MEPA Review Thresholds ................................................................................. 5 2.0 Existing Conditions ............................................................................................ 6 2.1 Existing Seawall and Revetment ....................................................................... 6 2.2 Wave Overtopping ............................................................................................ 8 2.3 Area of Critical Environment Concern ............................................................. 10 2.4 Rare Species .................................................................................................. 10 3.0 Alternatives Analysis ....................................................................................... 11 3.1 Development of Alternatives ........................................................................... 12 3.2 Description of Alternatives ............................................................................... 12 3.2.1 Alternative 1 – No Action .......................................................................... 12 3.2.2 Alternative 2 – Beach Nourishment .......................................................... 14 3.2.3 Alternative 3 – Nearshore Submerged Wave Break ................................. 16 3.2.4 Alternative 4 – Rehabilitation of the Existing Revetment and Seawall ...... 18 4.0 Project Description ........................................................................................... 21 4.1 Design Storm Conditions ................................................................................. 21 4.2 Development of Proposed Design ................................................................... 22 4.3 Proposed Design............................................................................................. 28 4.4 Relative Sea Level Rise .................................................................................. 30 5.0 Potential Environmental Effects of Preferred Design .................................... 33 5.1 Land Subject to Coastal Storm Flowage ......................................................... 33 5.2 Land Under the Ocean .................................................................................... 34 5.3 Coastal Beach ................................................................................................. 34 5.4 Barrier Beach .................................................................................................. 35 5.5 Coastal Bank ................................................................................................... 36 6.0 Regulatory Permitting ...................................................................................... 37 7.0 References ........................................................................................................ 38 Appendix A – Permitting Plans .................................................................................. 39 i Environmental Notification Form Crescent Beach, Hull, MA TABLE OF FIGURES Figure 1.1. Project area vicinity showing Gun Rock, Green Hill Rock and Straits Pond (map from MassGIS Statewide Basemap). ..................................... 1 Figure 1.2. Flood damage during the Blizzard of 1978 (photo from the Town of Hull). ........................................................................................................ 3 Figure 1.3. Overwashed sediment on Atlantic Avenue after a minor storm on October 23, 2014 (photo from the Town of Hull). ...................................... 4 Figure 1.4. Damaged asphalt and overwashed sediment and debris after a minor storm on October 23, 2014 (photo from the Town of Hull). ....................... 4 Figure 2.1. Slumping of rubble and grouted revetment (photo by Applied Coastal – June 3, 2015). Note the loss of armor stones into the offshore area and sheet piling used to prevent slumping................................................ 6 Figure 2.2. Spalling, cracking and breakage of the existing seawall (photo by Applied Coastal – March 26, 2015). ......................................................... 7 Figure 2.3. Splash-over and wave overtopping at Crescent Beach during the Patriot’s Day Storm of 2007 (photo from the Town of Hull). ...................... 7 Figure 2.4. Washed out road on Gunrock Avenue (photo by Applied Coastal – March 26, 2015). ...................................................................................... 8 Figure 2.5. Straits Pond and estimated high overwash area along Atlantic Avenue. Overwash fans and lack of vegetation suggests that overwash is severe along the 650 ft area on the west end of Crescent Beach. ...................................................................................................... 9 Figure 2.6. Cross-section from Crescent Beach to Straits Pond showing a 1:30 to 1:40 slope towards the pond. ................................................................... 9 Figure 2.7 Area of Critical Environment Concern (ACEC) and Outstanding Resource Water (ORW) in the vicinity of the Project Area. ..................... 10 Figure 3.1. Overwash and flooding of Atlantic Avenue (photo from the Town of Hull). ...................................................................................................... 11 Figure 3.2. Damage to asphalt caused by wave overtopping and overwash (photo from the Town of Hull). ................................................................ 11 Figure 3.3. Properties with multiple federal flood insurance claims from Nantasket Beach to Cohasset Harbor. Many homes on the north and south side of Atlantic Avenue behind the Crescent Beach revetment have been damaged repeatedly. ............................................................ 13 Figure 3.4. Approximate footprint of a potential large-scale nourishment project. ..... 14 Figure 3.5. Accumulation of nourishment material behind breakwaters at Winthrop Beach (photo from Google Earth). ........................................... 15 Figure 3.6. Photograph of the Shark Island WADTM project completed in New Iberia, Louisiana (www.livingshorelinesoultions.com). ............................ 17 Figure 4.1. Model output for the 100-year return period wave condition (26.3 ft and 15 s waves from the northeast). Colors indicate wave heights and vectors show peak wave direction. .................................................. 21 ii Environmental Notification Form Crescent Beach, Hull, MA Figure 4.2. Critical values of average overtopping discharges (USACE, 2002). ....... 23 Figure 4.3. Stationing along the Crescent Beach seawall (1 station = 100 feet). ...... 24 Figure 4.4. Average overtopping discharge along the length of the seawall where the revetment elevation is raised to 17 ft MLW. Black dash-dot line shows the critical value of average overtopping discharges for revetments backed by unpaved surfaces. .............................................. 24 Figure 4.5. Average overtopping discharge along the length of the seawall where the revetment elevation is raised to 23 ft MLW. Black dash-dot line shows the critical value of average overtopping discharges for revetments backed by unpaved surfaces. .............................................. 25 Figure 4.6. Average overtopping discharge along the length of the seawall where the revetment elevation is raised to 25 ft MLW. Black dash-dot line shows the critical value of average overtopping discharges for revetments backed by unpaved surfaces. .............................................. 25 Figure 4.7. Seaward extent of revetment toe for a 17 ft MLW revetment with 1.5, 1:2, 1:2.5 and 1:3 revetment slope. Extents are representative for Option 1, 2 and 3. ................................................................................... 26 Figure 4.8. Seaward extent of revetment toe for a 23 ft MLW revetment with 1.5, 1:2, 1:2.5 and 1:3 revetment slope. Extents are representative for Option 4, 5 and 6. ................................................................................... 27 Figure 4.9. Seaward extent of revetment toe for a 25 ft MLW revetment with 1.5, 1:2, 1:2.5 and 1:3 revetment slope. Extents are representative for Option 7. ...............................................................................................