EL CAMINO REAL
STORMWATER AND DRAINAGE
IMPROVEMENTS
TOWN OF ATHERTON
January 22nd, 2025
Eric Biland, P.E.
FLOODING EVENTS
EL CAMINO REAL CORRIDOR
IMPACT ON COMMUNITY
FLOODING SOLUTIONS
EXISTING DRAINAGE SYSTEM
OVERVIEW
PRELIMINARY COST
ESTIMATE
CONCEPTUAL DESIGN
A G E N D A
EXISTING DRAINAGE SYSTEM
EXISTING DRAINAGE SYSTEM
REPORTED FLOODING
EL CAMINO REAL CORRIDOR
AND SITE OBSERVATIONS FROM DECEMBER 2024
IMPACT ON COMMUNITY
SAFETY
• PEDESTRIAN
• BIKING
• DRIVING
PROPERTY IMPACTS
• PROPERTY FLOODING
DRAINAGE SOLUTIONS
POINT SOLUTIONS
STORMDRAIN
SYSTEM
• Utility
Conflicts
• Available
discharge
points
INFILTRATION
WELLS
• Low
maintenance
costs
• Ineffective
• Slow draining
24”
18”
DEWATERING
SYSTEM
12”
• Stored volume: 13,500 CF
• Total pumped volume: 16,700 CF
FLOODING SOLUTION
ALTERNATIVES
• Stored volume: 9,300 CF
• Total pumped volume: 12,500 CF
• Stored volume: 4,800 CF
• Total pumped volume: 8,000 CF
• CONSTRUCTABILITY
• COSTS
• MINIMAL ENVIRONMENTAL IMPACT
• IMPROVED TRASH CAPTURE AND WATER QUALITY
• INTEGRATION WITH EL CAMINO REAL IMPROVEMENTS
PROPOSED FLOODING
ALTERNATIVES
STORM/OVERLAND
FLOW
STORM DRAIN SYSTEM
AND OVERLAND RELEASE
LOCALIZED FLOODING AND PONDING
PUMPING TO ATHERTON
CHANNEL
IS ATHERTON
CHANNEL
PEAKING?
LEVEL FLOAT IN LIFT
STATION ACTIVATED
N Y
PROPOSED DEWATERING SOLUTION
PUMPS OFF
PROPOSED SOLUTIONS OVERVIEW
DEWATERING SYSTEM
PROPOSED SOLUTIONS OVERVIEW
EL CAMINO REAL IMPROVEMENT PLAN
ENGINEER’S COST ESTIMATE
ESTIMATED PROJECT COST
ANTICIPATED OVERALL COSTS/ ALLOWANCES
Item No Item Unit Quantity Unit Price Total Cost
DESIGN / BID DOCUMENTS
1 Final Design and Bid Support LS 1 $275,000 $275,000
PERMITTING
2 Caltrans LS 1 $7,500 $7,500
3 PG&E LS 1 $30,000 $30,000
ENVIRONMENTAL
4 CEQA Processing and Environmental Assessments LS 1 $65,000 $65,000 5 Regulatory Agency Compliance LS 1 $75,000 $75,000
CONSTRUCTION MANAGEMENT
6 Construction Administration LS 1 $265,000 $265,000
CONSTRUCTION COSTS
7 Mobilization/ SWPPP/ Traffic Control LS 1 $180,000 $180,000 8 Drain Inlets/Manholes/Laterals LS 1 $455,000 $455,000 9 Horizontal Directional Drilling LS 1 $2,700,000 $2,700,000 10 Grading LS 1 $260,000 $260,000
11 Pump Station LS 1 $400,000 $400,000
13 Contingency (10% of Construction Costs) LS 1 $399,500 $399,500 Total $5,122,000
ENGINEER’S COST ESTIMATE
ESTIMATED ANNUAL
MAINTENANCE COST
ESTIMATED ANNUAL MAINTENANCE COSTS
Item No Item Unit Quantity Unit Price Total Cost
MAINTENANCE
1 Vactor Service Day 2 $4,800 $9,600
2 2-Man Crew Day 8 $1,600 $12,800
3 Pump Station Service EA 2 $3,500 $7,000
4 Screen Inserts Replacement Allowance EA 2 $2,500 $5,000 Maintenance Budget $34,400
Thank You!
Questions?