Living with the Nearshore Beaches Seawalls and What
Living with the Nearshore: Beaches, Seawalls and What lies in Between Presented to University of Washington Department of Landscape Architecture Prepared by Peter Hummel, ASLA, Anchor Environmental May 13, 2005
Presentation Overview • • • Understanding the Nearshore Blending Human Uses with Habitat Nearshore Project Examples Summary-Key Questions and Discussion
Understanding the Nearshore • • • What is the Nearshore Physical Processes Ecological Functions of the Nearshore Location in the Landscape Habitat Modifications and Effects
Understanding the Nearshore Source: King County Department of Natural Resources
Nearshore Physical Processes Source: http: //meted. ucar. edu/marine/ripcurrents/NSF/print. htm
Understanding Waves Source: http: //meted. ucar. edu/marine/ripcurrents/NSF/print. htm
Sediment Supply • Drift cell based • Sediment supply potential • none • low • moderate ● high ● exceptional • Sediment supply connectivity • none • low ● moderate ● high
Sediment Supply Analysis
Essential Functions of Nearshore for Juvenile Salmon • • • Food Production Predator Refuge Physiological Refuge High-energy Refuge Migratory Corridor
Ecological Functions of Nearshore Habitats Food Resources Beneficial Habitat Parameters Embayment + Forage Fish Distributions + Eelgrass + Proximity to Salmon Trib. + Emergent Marsh + Riparian Overhang + Intertidal Vegetation + Predator Refuge Physiol. Refuge Energy Refuge Migration Corridor + + + + + Extended Segment * Importance in habitat-forming processes Habitat Type/ Sediment Sup. Unquantified importance / importance in habitat-forming processes Notes: *This attribute only applied for shoreline segments identified as having exceptional or high sediment supply potential Yellow text. Habitat parameters that receive a weighting factor
Landscape Position: South Sound
Landscape Position: Seattle
Nearshore Habitat Modifications & Effects: Conceptual Model Impacts · · Shoreline modifications Pollution Controlling Factors · Depth · Substrate · Slope · Light · Salinity · Vegetation Habitat Structures · Vegetation density · Vegetation biomass · Diversity · Patch size and shape · Landscape position Source: Williams and Thom (2001) Habitat Processes Juvenile Salmonid Needs · Production · Food production · Shading · Predator Refuge · Sediment flux · · Nutrient flux Physiological Refuge · Energy Refuge · Migratory Corridor
Blending Human Uses with Habitat • Habitat Perspective: ü How Good and How Altered • Human Use Perspective: ü Existing & Proposed Uses and Facilities ü Space and Property Lines ü Cost/Benefits • Feasibility: ü Restoration Versus Enhancement of Specific Ecological Functions
Restoration Prioritization Site Features Habitat Opportunities Habitat Constraints Habitat Improvement Potential No Action. Conserve Site Landscape Considerations Park Use Opportunities Combined Improvement Potential Source: Seattle Parks Shoreline Inventory and Habitat Assessment Site Location Restoration Feasibility Reach Restoration Priority • • • Park Use Constraints No Action- Conserve Site High Priority Medium Priority Low Priority No Action- Use Conflict
Results of Prioritization
How Good and How Altered
Restoration Example: Rainier Beach Lake Park
Rainier Beach Lake Park Restoration Opportunitie
Rainier Beach Design Concept
Rainier Beach Design Concept
Restoration Example: Martha Washington Park Existing Condition
Martha Washington Park Restoration Opportunities
Martha Washington Design Concept
Martha Washington Design Concept
Martha Washington Park Construction
Martha Washington Park Completion
Restoration Example: Seahurst Park • Microcosm of Puget Sound Shoreline Habitats • Habitat Forming Processes Restoration Opportunity • Shoreline and Park Master Plan
Shoreline Restoration Goals • Preserve existing functioning nearshore habitats • Remove existing shoreline protection structures • Model restored beach slopes and substrates after natural on-site and adjacent reference beaches • Replenish gravel and sand lost to bulkhead induced erosion • Restore and protect the natural hillside sediment delivery paths
Station 10+00 Pre-Construction
Station 10+00 Construction (Sand/Gravel over Base Gravel)
Station 10+00 Completed Beach
Lower Beach Rock Removal Mid Project Before Mid Project After
Beach Monitoring Initial Results Beach Profiles: 1973, 2004, 2005 Beach Sediment Sample Source: Johannessen, Coastal Geologic Services, 2005
Required Biological Monitoring Pre-Project Initial Results Eelgrass Survey Forage Fish Monitoring
Desirable Biological Pre-Project Monitoring Initial Results Epibenthic On-Site Sampling Source: Toft, UW Wetland Ecosystem Team, 2005 Location Comparisons
Restoration Example: Squalicum Waterway Existing Conditions
Restoration Example: Dickman Mill Park
Restoration Example: Golden Gardens Park
Terracing Example: Sunnyside Beach Park
Terracing Example: Thea Foss Esplanade
Terracing Example: Thea’s Park
Seawall Beach Fill Example: Seacrest Park
Seawall Beach Fill Example: Olympic Sculpture Park
Summary-Key Questions • What is the Position of the Site in the Larger Nearshore Landscape? • What were the Site’s Historic Conditions and Ecological Functions? • Can Habitat Forming Processes be Restored? • What are the Spatial Requirements of Existing and Proposed Human Uses and Facilities? • What are the Costs/Benefits of Restoration at This Site? • What Specific Ecological Functions can the Project Enhance?
Questions and Discussion
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