20210901-003a: Update on Northwest Park Dam Maintenance & Modernization Project — original pdf

Backup

Shoal Creek – Northwest Park Dam Maintenance and Modernization Project Environmental Commission September 1, 2021 C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Pam Kearfott, PE, CFM Annabell Ulary, PE, CFM Dam Safety: Program Overview 3 3 d a m s i n Au s t i n r e g u l a t e d by TC E Q * Height Volume Downstream Risk TC E Q s a f e t y r e q u i r e m e n t s Structural stability Ability to safely pass % of PMF (Probable Maximum Flood) • W P D m a n a g e s D a m S a f e t y P ro g r a m Inspections Emergency Action Plans Routine maintenance and repairs CIP projects for modernization & large repairs • • • • • • • • • • • C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T * Texas Commission on Environmental Quality Northwest Park Dam and Regional Detention Facility C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Northwest Park Dam and Regional Detention Facility: How it Works * 100-year Floodplain Shoal Creek Top of Dam Inflow Spillway C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Northwest Park Dam and Regional Detention Facility: How it Works Creek side 100-year Floodplain Shoal Creek Top of Dam Inflow Spillway Outfall Pipe C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Northwest Park Dam and Regional Detention Facility: How it Works 100-year Floodplain Shoal Creek Top of Dam Inflow Spillway Outfall Pipe Auxiliary Spillway C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Northwest Park Dam and Regional Detention Facility: How it Works 100-year Floodplain Shoal Creek Top of Dam Inflow Spillway Outfall Pipe Auxiliary Spillway C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance and Modernization Project: Overview Dam Safety • Regulated requirements for structural stability • Texas Commission on Environmental Quality • City of Austin Drainage Criteria Manual Dam Maintenance • Items that don’t currently impact the stability of the dam Park Drainage and Water Quality • Coordinated with PARD Vision Plan • Has no impact on the structural stability of the dam C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements AREA 1 3 2 4 1 AREA 4 AREA 3 AREA 2 • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Safety Improvements • OVERTOPPING PROTECTION • WARNING SIGNS** • WOODY VEGETATION MANAGEMENT AND ESTABLISHING RIPARIAN VEGETATION CREEKSIDE REHABILITATION OF THE EMBANKMENT EVALUATE THE VERTICAL MSE WALLS** • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Dam Maintenance Improvements • PEDESTRIAN BRIDGE EXPANSION PLATES • REMOVING IRRIGATION SYSTEM IN EMBANKMENT POST-INSTALL DRAINAGE AND SEALING CRACKS/JOINTS FOR RETAINING WALLS STABILIZE BASEBALL STRUCTURES** EROSIVE FOOT TRAFFIC WALKWAYS** LOCAL EROSION REPAIR** • • • • ** Items Correlated with PARD’s Vision Plan C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Estimated Project Cost* Dam Safety Improvements Dam Maintenance Improvements Total Project Cost * Approximate Cost estimate based on the current phase $2M $1M $3M C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T Project Timeline* WE ARE HERE 2020 2021 2022 2023 2024 2025 Preliminary Engineering Project Design Project Construction C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T * Estimate timeline based on the current phase Questions? C I T Y O F A U S T I N W A T E R S H E D P R O T E C T I O N D E P A R T M E N T