Storm Water Improvements

Transcription

1 Storm Water Improvements The unusually heavy rain storms this past winter raised community awareness and interest in the City s storm water infrastructure system. Public Works was asked to study the system and report on ways to improve it. This presentation is a part of the accompanying report. Public Works Department Claudette Ford, Acting Director

2 Storm Water Improvements This presentation focuses on current systemic issues, offers short- and long-term programs for repairing the system, and the costs associated with such a program.

3 Sacramento Street Flooding February 25, 2004 Backup of Potter Street Outfall One block off main line

4 Kains Trash Rack Feb 25, block N of Gilman; 1 block E of San Pablo Shows volume of water flowing down Codornices Creek

5 Corner Flooding (cross culvert) February 15, 2005

6 2828 San Pablo Avenue December 18, 2005 Backup from Potter System

7 Background Severe storms in Winter heightened public awareness of the City s storm drain infrastructure problems year-old storm drain system : 100 miles long; 1200 manholes, 2800 catch basins, 2300 cross culverts. 2. We have a large backlog of repair and maintenance work with many sections severely overdue for rehabilitation. 3. Remediation will cost an estimated $84 million. 4. Funding issues: stagnant fees; little if any legislative assistance.

8 Big Storm Frequencies 12/17/05 15 year storm for 20 minutes at same time as 5.8 ft high tide capacity problem with backups and serious flooding 12/31/05 <5 year storm for 60 minutes at same time as 3.2 ft low tide localized problems with cross culverts and catch History: basins 12/29/03 10 year storm - flooding 2/25/04 >25 year storm - flooding

9 Main reasons for flooding Our storm water system is unable to meet demands placed on it by large storms such as those in February 2004 and December In addition to the rainfall and tidal effects, we have problems with: Severely deteriorated storm drain system Clogged catch basins and inlets (leaves, debris) Storm drain systems at or over capacity

10 Clean Storm Water Fund - FY FY 2006 Maintenance/Regulatory Compliance $1,400,000 Creeks Task Force 100,000 Capital Improvements 400,000 $1,900,000 FY 2007 Maintenance/Regulatory Compliance $1,400,000 Capital Improvements 1,292,000 (including 500K CIP; $2,692,000 one-time 292K allocation; 200K UC Agreement; 300K BUSD Agreement) FY 2008 Maintenance/Regulatory Compliance $1,400,000 Capital Improvements 700,000 (including 500K CIP; 200K UC) $2,100,000

11 MAINTENANCE ISSUES Dry Periods (approximately 36 weeks/year) One 2-person crew: Per Per Per Maintenance Item Day Week Year* Inlets/outlets ,880 Catch basins ,880 Junction boxes Culvert feet** 240 1,200 43,200 Wet Periods (approximately 14 weeks/year) Four 2-person crews: Inlets/outlets ,400 Catch basins Junction boxes Culvert feet** ,810 *May represent multiple visits to same problem sites. **Harder to service during rain due to breakdowns.

12 Construction Program Priorities FY 2007 (FY 2006 Funds) $400,000 available for repairs to: Cragmont, creek culvert $ 55, th /Heinz, valley gutters 150, th /Heinz, valley gutter 60, th /Heinz, valley gutter 60, th /Heinz, catch basin work 30, Prince/Dohr, valley gutter 45,000 Estimated Total $400,000

13 Construction Program Priorities FY 2007 (FY 2007 Funds) 10 th /Grayson Valley gutter $ 65,000 Ward/Fulton Valley gutter 130,000 4 th /Jones Storm line extension 145,000 4 th /Virginina Storm line extension/catch basin 55,000 Dwight/MLK Gallery catch basins (3) 55,000 Cedar/Spruce Valley gutter 65,000 LaLoma Creek culvert 50, Shattuck Catch basin/pipe 67,000 Arch/Corona Ct Catch basin 25,000 9 th /Channing Cross culvert 130,000 Oregon/Shattuck New cross culverts (2) 155,000 Piedmont/Garber Valley gutter 65,000 Dana/Ward Valley gutter 65, th /Carleton Valley gutter 65,000 Ward/MLK Cross culvert 155,000 TOTAL $1,292,000

14 Looking Ahead 10 Years The capital outlay needed over the next 10 years for repairs would be: Cross culverts $ 6,565,000 Storm drain piping (underground) - Olympus/Shasta/Marin 23,400,000 Street flooding areas 7,560,000 Storm pipes/creek culverts on public property 10,000,000 Ground water misc issues 2,226,150 Total $ 49,751,150 Per year for 10 years 4,975,115

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16 Looking Ahead 25 Years Assumptions: System continues to deteriorate at an increasingly faster rate over time. If the 10-year expenditure plan could be implemented, only 1/4 to 1/3 of the capacity issues would be addressed. Without increasing capacity expenditures, the system will continue to deteriorate faster than our ability to fix and maintain it.

17 Potter & Strawberry Systems Capacity Improvements Potter Street System Oregon St Relief Storm Drain Sewer Increase capacity- reduce Flooding Adeline to San Pablo $ 13,400,000 Potter St Overflow Diversion - allows storm flow between Potter SD/Aquatic Park 2,100,000 Aquatic Park Pumping Station/Force Main - keeps water level down at Aquatic Park 4,200,000 Derby St Improvements 700,000 Parker St Improvements 500,000 Prince St Bypass 400,000 Potter Subtotal $ 21,300,000

18 Potter & Strawberry Systems - Capacity Improvements Strawberry System (relieves 2 nd Street flooding) Walnut St/Hearst Av Relief Storm Drain $ 3,700,000 Lower Hearst Ave Relief Storm Drain 4,700,000 Addison St Relief Storm Drain 3,900,000 Strawberry Subtotal $12,300,000 Plus: Potter Subtotal 21,300,000 Total based on 1994 study and dollars $33,600,000