Evaluation of Surf Zone Conditions For the City of Cape May Hatch - PowerPoint PPT Presentation

Replace entire gray box with one of your presentation’s images (bleed across the screen). Evaluation of Surf Zone Conditions For the City of Cape May Hatch Mott MacDonald Date 15 December 2015 www.hatchmott.com

Evaluation of Surf Zone Conditions • Outline of presentation:  Introduction and Background  Wave Assessment  Grain Size Evaluation  Beach Slope Evaluation  Alternatives  Numerical Model Results  Recommendations • Note: The information in this presentation is strictly engineering based, with no implied or actual health/medical recommendations. www.hatchmott.com

Cape May, Looking South Source: USACE www.hatchmott.com

Gurney Avenue, Cape May Source: USACE www.hatchmott.com

Philadelphia Avenue, Cape May Source: USACE www.hatchmott.com

Baltimore Avenue, Cape May Source: USACE www.hatchmott.com

Cape May’s Beaches  USCG Station – Cape May Inlet Jetty – Buffalo Ave./Yeaton Road  Cape May – Cape May Beach Club – Third Avenue groin www.hatchmott.com

Change in Beach Fill Templates  OLD Design: Federal Project (per Phase II GDM, 1983)  Design Berm Elevation: 8.0 ft NGVD 29  Design Berm Slope: 1V:25H  Design Berm Width: 25 -130 ft.  Nourishment interval: 2 years  CURRENT Design: Federal Project (per USACE FY 09 Monitoring Report)  Design Berm Elevation: 6.7 ft NAVD 88  Design Berm Slope: 1V:10H  Design Beach Width (Design Baseline to MLW (-2.8 ft NAVD 88)): 268 ft.  Nourishment interval: 2 years www.hatchmott.com

Historical Sediment Samples  Earliest known publically available data for NJ from the McMaster (1954) report Sediment Results from McMaster (1954) Sample Number Location Position on Beach Median Grain Size 0.17 miles south of 127 harbour jetty, Sewell Pt. Berm crest 0.130 mm Cape May 128 0.31 miles north of 20 ft below berm crest on 6 o slope (compare to CRC Wilmington Ave., Cape 0.357 mm #108) May (1V:9.5H) Beach controlled by 129 0.28 miles north of seawall. 15 ft from (compare to CRC 0.157 mm wall on 3 o slope Madison Ave., Cape May #107) (1V:18H) 15 ft below berm crest on 6 o slope 130 Perry Street, Cape May 0.182 mm www.hatchmott.com (1V:9.5H)

Historical Sediment Samples Sediment Results from USACE (1983) Sample Location Position on Beach Median Grain Size Number Berm 0.163 mm USCG, Sewell Pt. Cape 121 High tide 0.139 mm May Mid tide 0.187 mm Baltimore Avenue, 122 Mid tide 0.154 mm Cape May Municipal Pier, Cape High tide 0.144 mm 123 May Mid tide 0.132 mm www.hatchmott.com

Recent (Oct. 2015) Sediment Samples 2015 Data Collection by Hatch Mott MacDonald Sample Location Position on Beach Median Grain Size Number High tide 0.350 mm Cape May Beach Club, 108 Mid tide 0.450 mm Cape May Low tide 0.410 mm High tide 0.370 mm Baltimore Avenue, 107 Mid tide 0.470 mm Cape May Low tide 0.460 mm High tide 0.360 mm South Broadway Ave., 206 Mid tide 0.420 mm Cape May Low tide 0.430 mm www.hatchmott.com

Historical Profile Locations Baltimore Ave. Howard St. www.hatchmott.com

Howard Street Historical Profiles USACE Profile CM020 (Near Howard Street) 15 Sep. ‘06 10 Elevation (ft NAVD88) Sep. ‘14 MHW (approx.) 5 0 -5 MLW (approx.) -10 Mar. ‘87 -15 -20 -25 0 200 400 600 800 Distance from Baseline (ft) CM020 1987_03 CM020 2006_09 CM020 2014_09  Data from USACE  Profiles for March 1987 ( blue line ), September 2006 ( red line ), and September 2014 ( green line ) www.hatchmott.com

Howard Street Historical Profiles USACE Profile CM020 (Near Howard Street) USACE Profile CM020 (Near Howard Street) 15 15 Sep. ‘06 10 10 Elevation (ft NAVD88) Elevation (ft NAVD88) Sep. ‘14 MHW (approx.) 5 5 0 0 -5 -5 MLW (approx.) 10 ft -10 -10 Mar. ‘87 10 ft -15 -15 -20 -20 -25 -25 0 0 200 200 400 400 600 600 800 800 Distance from Baseline (ft) Distance from Baseline (ft) CM020 1987_03 CM020 2006_09 CM020 1987_03 CM020 2006_09 CM020 2014_09  Data from USACE  Profiles for March 1987 ( blue line ), September 2006 ( red line ), and September 2014 ( green line ) www.hatchmott.com

Baltimore Ave. Historical Profiles MHW (approx.) MLW (approx.) Oct. ‘86 Aug. ‘06  Data from Stockton University NJ Beach Profile Network database  Profiles for October 1986 (red dashed line) and August 2006 (black solid line) www.hatchmott.com

Baltimore Ave. Historical Profiles MHW (approx.) MLW (approx.) Sep. ‘15 Oct. ‘15  Data from Stockton University NJ Beach Profile Network database  Profiles for September 2015 (red dashed line) and October 2015 (black solid line) www.hatchmott.com

Waves  USACE Wave Information Studies (WIS) Station Cape May City 63152 Data  1980 - 2012 (USACE WIS) WIS Station No. 63152 Analysis Results for a 2 ft Wave Parameter Value Average Tm for Hmo = 2 ft 6.6 seconds Average θ for Hmo = 2 ft and Tm = 6.6 ± 0.01 seconds 124º from True North www.hatchmott.com

Howard Street www.hatchmott.com

Wave Breaker Type  Typical wave beaker types: – Spilling – Plunging – Collapsing – Surging Galvin (1968) www.hatchmott.com

Wave Breaker Type  Wave breaker type can be determined by the Surf Similarity Parameter/Iribarren number, 𝜊 0 : 𝑢𝑏𝑜𝛾 𝜊 0 = (Battjes, 1974) 𝐼0 𝑀0 Where: » 𝑢𝑏𝑜𝛾 = Slope » 𝐼 0 = Offshore wave height » 𝑀 0 = Deep water wavelength  Wave breaker type range: – Collapsing or Surging: 3.3 < 𝜊 0 – Plunging: 0.5 < 𝜊 0 < 3.3 – Spilling: 𝜊 0 < 0.5 www.hatchmott.com

Wave Breaker Type Expected Breaker Calculated Surf Similarity Parameter Based on Slope Type 3.50 Collapsing or Surging Surf Similarity Parameter 3.00 2.50 2.00 Plunging 1.50 1.00 0.50 Spilling 0.00 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 Beach Profile Slope (tan β ) www.hatchmott.com

Wave Breaker Type Expected Breaker Calculated Surf Similarity Parameter Based on Slope Type 3.50 Collapsing or Surging Surf Similarity Parameter 3.00 2.50 2.00 Plunging 1.50 1.00 0.50 Spilling 0.00 0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 Beach Profile Slope (tan β ) Change between spilling and plunging breaker type occurs at a 1V:21H slope www.hatchmott.com

Expected Wave Breaker Types Surf Similarity Profile Slope Expected Breaker Type Parameter Baltimore Ave. 1V:40.7H 0.26 Spilling 1986 Baltimore Ave. 1V:7.6H 1.40 Plunging 2015 1V:10H Hypothetical A 1.06 Plunging 1V:25H Hypothetical B 0.42 Spilling www.hatchmott.com

Wave Model Results Baltimore Ave. 1986 Profile: 1V:40.7H Baltimore Ave. 2015 Profile: 1V:7.6H www.hatchmott.com

Turbulent Dissipation (Joules/(kg/s)) Hypothetical Profile: 1V:10H Slope Hypothetical Profile: 1V:25H Slope  Energy dissipation is more rapid in the plunging wave for 1V:10H than 1V:25H  Energy dissipation is confined to a smaller region in the plunging wave for 1V:10H www.hatchmott.com than 1V:25H

Alter Beach Slope – Baltimore Avenue (Initial design investigation) Baltimore Ave. Alternative 20 Sep. ‘15 Elevation (ft NAVD88) 15 10 5 0 -5 Alternate -10 1V:25H -15 -20 0 100 200 300 400 500 600 700 800 Distance from Baseline (ft) Alternate Profile with 1V:25H slope 9.17.2015 Stockton Survey www.hatchmott.com

Alter Beach Slope – Baltimore Avenue (Initial design investigation) Baltimore Ave. Alternative 20 Sep. ‘15 Elevation (ft NAVD88) 15 10 MHW (approx.) 5 0 -5 MLW (approx.) Alternate -10 1V:25H -15 -20 0 100 200 300 400 500 600 700 800 Distance from Baseline (ft) Alternate Profile with 1V:25H slope 9.17.2015 Stockton Survey www.hatchmott.com

Alter Beach Slope – Baltimore Avenue (Initial design investigation) Baltimore Ave. Alternative 20 Sep. ‘15 Elevation (ft NAVD88) 15 10 MHW (approx.) 5 0 -5 10 ft MLW (approx.) Alternate -10 10 ft 1V:25H -15 -20 0 100 200 300 400 500 600 700 800 Distance from Baseline (ft) Alternate Profile with 1V:25H slope 9.17.2015 Stockton Survey www.hatchmott.com

Alter Beach Slope – Howard Street (Initial design investigation) Howard St. Alternatives 15 Alternative 2 Elevation (ft NAVD88) 10 1V:25H 5 0 -5 -10 Sep ‘14 -15 -20 Alternative 1 -25 1V:25H -30 0 100 200 300 400 500 600 700 800 900 1000 Distance from Baseline (ft) Alternative 1 Alternative 2 USACE CM020 2014_09 www.hatchmott.com

Alter Beach Slope – Howard Street (Initial design investigation) Howard St. Alternatives 15 Alternative 2 Elevation (ft NAVD88) 10 1V:25H MHW (approx.) 5 0 -5 MLW (approx.) -10 Sep ‘14 -15 -20 Alternative 1 -25 1V:25H -30 0 100 200 300 400 500 600 700 800 900 1000 Distance from Baseline (ft) Alternative 1 Alternative 2 USACE CM020 2014_09 www.hatchmott.com

Alter Beach Slope – Howard Street (Initial design investigation) Howard St. Alternatives 15 Alternative 2 Elevation (ft NAVD88) 10 1V:25H MHW (approx.) 5 0 -5 15 ft MLW (approx.) -10 Sep ‘14 15 ft -15 -20 Alternative 1 -25 1V:25H -30 0 100 200 300 400 500 600 700 800 900 1000 Distance from Baseline (ft) Alternative 1 Alternative 2 USACE CM020 2014_09 www.hatchmott.com