South Coast Water District

Transcription

1 South Coast Water District Providing Quality Water & Wastewater Services To the Coastal Communities SOUTH LAGUNA TUNNEL STABILIZATION & SEWER PIPELINE REPLACEMENT PROJECT Resolution of Necessity Hearing May 14, 2015

2 Resolution of Necessity Hearing Open Public Hearing Staff Report and Presentation Written and Oral Objections and Protests by Landowner Public Comments and Requests to be Heard Close Public Hearing 2

3 Findings Does the public interest and necessity require the Project? Is the Project planned or located in the manner that will be most compatible with the greatest public good and least private injury? Is each easement interest necessary for the Project? Has an offer of just compensation been made to each Property Owner? 3

4 Recommended Actions Make Findings Consider Adoption of Resolution of Necessity for the Property 4

5 Tunnel Facts Blasted, hand dug in 1954 Three Arch Bay to Aliso Beach, two miles long Generally 6 ft x 6 ft Sewage flows: 1 MGD average 2 MGD peak Timber supported sections Original sewer line replaced in 1974 Tunnel Failure Results in Large Sewer Spill into Ocean 5

6 Tunnel Condition Poor Tunnel Condition Studies (1997, ) Annual Inspections & Repairs Required Unlined & Unsupported in Sections Deteriorating Condition Unsafe for Entry, Repair, & Maintenance Work 6

7 Current Tunnel Conditions Deteriorating Tunnel tree roots, falling rocks & dirt Workers and sewer line at risk 7 All require constant repairs Decaying support beams

8 Current Conditions vs. Completed Project Existing 8 Completed

9 Summary of Project Benefits Tunnel stabilization & sewer pipeline replacement project will: Ensure reliable sewer service for next 100+ years Prevent worker injury or death Continue operation without generating greenhouse gases Avoid the disastrous consequences of millions of gallons of sewage spilling onto the beach and into the ocean Protect Marine Life Fisheries 9

10 Marine Refuges Adjacent to Tunnel Location State Marine Conservation Area State Marine Reserve State Marine Conservation Area (No-Take) Tunnel Location 10 Tunnel Location

11 Sewer Tunnel Location & Jurisdictional Areas Portal 2 4th Avenue Drop Manhole AREA UNDER CITY OF LAGUNA BEACH LCP AREA OF DEFERRED CERTIFICATION Aliso Beach 11 Tunnel Length = 10,400 feet CEQA certified by SCWD Board of Directors on November 11, 2010 by Resolution #11-10/11 Addendum 1 to EIR Tunnel Realignment at 90 South La Senda approved March 28, ,300 LF within City of Laguna Beach LCP (Coastal Development Permit approved on December 11, 2013) 4,100 LF within Area of Deferred Certification (CDP approved by Coastal Commission on December 10, 2014) Three Arch Bay

12 12 Project Alternatives evaluated in CEQA Process 1. No Project 2. Backfill and Abandon Tunnel, Pipeline Remains in Service 3. Abandon Tunnel, Replace with Pipe in PCH and Numerous Lift Stations 4. New Monarch Beach Pump Station and Smaller Pipe in Existing Tunnel 5. Slip Line Techite Pipe and Limited Tunnel Repairs 6. New Parallel Tunnel and Abandon Existing Tunnel Approved Project: Encase Pipe and Repair Tunnel

13 Project Alternatives Project Alternatives 1 thru 6 not selected Infeasible, Impractical Too Disruptive Cost Prohibitive Greater Impacts to Community Greater Impacts to Private Property 13

14 14 Approved Project: Encase Pipe and Rehabilitate Tunnel Feasible Mitigates Risk of Injury and Sewer Spills Least Disruptive Least Impacts to Community Least Private Injury Greatest Public Good

15 Approved Tunnel Rehabilitation Plan Enlarged Tunnel Existing Tunnel New Pipeline Existing Pipeline ~6 FT 15 ~6 FT

16 Tunnel Rehabilitation & Realignment Requires Easements Hired appraiser to value interests Easement offers to acquire made to 184 owners of private property 194 of 196 interests acquired Two remaining easements to be acquired 16

17 Location of Remaining Easements 90 South La Senda 90 South La Senda 17

18 Property Considered for Adoption of Resolution of Necessity 90 South La Senda Owner and APNs: SMULL APN SMULL APN Realigned Tunnel 18

19 Tunnel Realignment at 90 South La Senda in Three Arch Bay Issues Existing tunnel in Three Arch Bay passes in close proximity to past landslides Several hundred feet of the tunnel between Adit 25 and drop manhole have been previously backfilled and sealed with a bulkhead Solution Realign a portion of the tunnel inland away from the bluff and known prior landslide areas 19 Abandon bypassed section of the existing tunnel from Adit 25 to drop manhole

20 Alternatives Analysis (S. La Senda Drive) SCWD considered two alternatives for S. La Senda Drive Re-alignment portion of project: Alternative A Realigned tunnel diverted before Adit 25, with new tunnel turning inland beneath residence at 90 S. La Senda Drive. Tunnel will continue beneath South La Senda Drive to the drop manhole at beginning of existing tunnel, resulting in total length of 720 feet of new tunnel. 20 Alternative B Realign tunnel at inflection point beneath Bay Drive, cross under residence at 17 Bay Drive & continuing beneath Barranca Way & S. La Senda Drive, resulting in 1,310 feet of new tunnel. With no feasible way to connect 12 existing sewer laterals to new tunnel, reconstruction & continued maintenance of 702 feet of existing tunnel required in addition to 1,310 feet of new tunnel. Would present operational challenges (increased sewer gases & odors, with added potential for pipeline blockages & possible overflows).

21 Three Arch Bay Realignment Alt A Shorter new tunnel, passes under S. La Senda Dr. residence Allows for Greatest Public Good & Least Private Injury 21

22 Three Arch Bay Realignment Alt B Longer new tunnel, passes under Bay Drive residence Rehabilitate 702 feet of existing tunnel for lateral access 22

23 Three Arch Bay Realignment Alt A & B Sewer Service Connection South La Senda Drive Existing Residence Alternative B Option 1 Sump Pump Existing Ground Surface (typ.) Sewer Main Alternative B Option 2 Sewer Lateral Alternative B Tunnel Alignment Not Recommended Alternative A (Keep Existing Lateral) Alternative A Tunnel Alignment 23

24 Review of Alternatives A & B Alternative A recommended by experts and selected by SCWD; resulting in one tunnel, requiring least amount of new, realigned tunnel, fewer lateral modifications & significantly less disruption to individual Three Arch Bay residents and community 24

25 25 Questions?