Watermain Replacements September 4, 2019 September 18, 2019 - - PowerPoint PPT Presentation

Zone 3 Aquifer Expansion and General Watermain Replacements

September 4, 2019 September 18, 2019

• 1. Alternative Approval Process (AAP)
• 2. Water System Overview
• 3. Aquifer Capacity Overview
• 4. Schedule

Overview

AAP Scope

• 25 Year Term
• Debt payments estimated at $182,000/year
• Debt payments offset by bulk water savings
• Future Development Cost Charges (DCCs) could also be used to offset

principle

Financing Details

Financial Impact of Expansion

• Comparison of two options (Status

Quo vs expansion):

• Over life of assets, overall costs of

expansion significantly lower than status quo

• Comparison includes capital,
• perations, and maintenance

Wells 5 and 6

• Average Daily Demand ~7200 pop.
• Maximum Daily Demand ~6000 pop.

Wells 1, 3, 4, 6

Assume one well out of service (redundancy for maintenance)

System Overview – Three Zones, Two Sources

Z3

Th Three zones

• Zones 1 and 2 - Gibsons Aquifer
• Zone 3 - SCRD water
• Allows appropriate pressure

Two So Sources

• Lack of infrastructure
• Prior to 2015, inadequate aquifer

capacity…

Z2 Z1

How does the Town’s water system operate?

Supply wells Water flows from reservoir to Zone 1 Water flows from reservoir to Zone 2 School Rd Reservoir – Fire flow, MDD, PHD Water pumped from wells to School Rd Parkland Reservoir – Fire flow, MDD, PHD Water pumped from School to Parkland 6 1 3 4 5 7

Zone 3 supply - Now

Valves between Zones - automatically open in the event of fire

Zone 3 Zone 2 SCRD supply Zone 1

Zone 3 supply with new pump station

Valves between Zones - automatically open in the event of fire

Zone 3 Zone 2 Zone 1 Pumphouse and chlorinator – ADD & MDD SCRD – Peak Hour, Emergency Storage, Fire Flow Watermain

• 1. What assets do you own? (inventory)
• 2. What is the asset worth?
• 3. What is the asset condition?
• 4. Establish your operations and management plan
• 5. Establish your financial plan
• 6. Assess the ability of the asset to increased demand
• 7. Ongoing assessment

Managing our Natural Asset: Aquifer Capacity

“In addition to monitoring the existing well network, additional wells will likely need to be installed in advance of significant land development in order to understand the cumulative effects that the proposed development will have

• n the aquifer.”

Aquifer Mapping Study, p. 91

“Climate change/variability and the effects on aquifer recharge are somewhat uncertain and can only be quantified by long-term monitoring trends and assessing cause and effect response in the aquifer.”

Aquifer Mapping Study, p. 86

Annual Groundwater Monitoring

• Annual program since 2009
• Eight Town monitoring wells
• Includes new wells to monitor

pressure and salt water intrusion

• Four production wells
• Some private wells monitored

• Modeled capacity of Aquifer
• 1.66 million cubic metres/year
• Assumptions:
• 15% reduction in overall recharge
• 50% reduction in snow pack
• 1 metre rise in sea level

Aquifer Capacity & Climate Change

“In summary, the Gibsons Aquifer should be able to supply the Town’s water supply needs [7300 pop] even under moderate to extreme climate change predictions. If long-term groundwater monitoring data indicates that threshold limits are being approached, then there may be a need to abandon existing supply wells located near the coast and replace them with wells located further from the coast.”

Aquifer Mapping Study, p. 89

Aquifer Capacity & Climate Change

• Metered supply:
• ~ 370 lcd
• Metered residential:
• < 200 lcd

Aquifer Capacity and Water Metering

Town initiates universal metering Physical separation from Zone 3

Litres per capita per day - includes residential, commercial, leaks

Aquifer Mapping projections

2018

• Modeled capacity of Aquifer
• 1.66 million cubic metres/year
• Projected Use (2011 calculation)
• 570 l/c/d /1000 x 7,300 persons x 365 days =

1.52 million m3/year (Buildout Zones 1 & 2)

• Projected Use (2018 calculation)
• 400 l/c/d /1000 x 10,000 persons x 365 days =

1.46 million m3/year (Buildout Zones 1, 2 & 3)

Zone 3 Service Area Expansion

4600 2017 4880 2020 5390 2025 5950 2030 6570 2035 7250 2040 8010 2045 8840 2050 9760 2055 10000 2060 10000 2065 10000 2070 400 800 1200 1600 2000

Total Water Volume (cubic meters x 1000)

Proposed Gibsons Aquifer Water Use and Capacity

Aquifer capacity Amended licence Exg well use Z1 & Z2 800 lcd (2008) Z1 & Z2 573 lcd (2011) Z1, Z2, Z3 400 lcd

Aquifer capacity Z1 & Z2 License Z3 License

Population: Year:

✓ Completed 2009-2013 Aquifer study ✓ Mapped extents ✓ Determined recharge area ✓ Aquifer capacity = Town buildout ✓ Asset Management Policy includes Natural Assets ✓ DPA9 (aquifer protection) ✓ Water regulation bylaw updates ✓ Zoning bylaw – no drilling permitted ✓ DCC Bylaw – includes cost of using natural assets ✓Well inspections ✓Monitoring well network ✓Long-term monitoring Program ✓Enhanced Sampling Program ✓Universal Metering Program ✓Cross Connection Control (CCC) Program ✓Proposes Town/SCRD Groundwater Mgmt Zone ✓Opened discussions with FLNRO re logging practices

Town Stewardship of the Aquifer Watershed:

Ministry of Forests, Lands, Natural Resource Operations & Rural Development:

“We are very impressed by the effort and approach that the Town is taking to protect the Gibson Aquifer and plan for a sustainable future. It is evident that the Town is very forward-thinking, and truly values the water resource.”

Timeline:

• Aug 26 to Sept 25 2019 – AAP response period
• Oct 2019 – Tender award (assuming successful AAP)
• Nov 2019 to May 2020 – Pump station construction
• Mar 2020 to May 2020 – Watermain construction
• 2021 – Commission Well 6
• 2022 (?) – Consider commissioning Well 5
• 2049 (+/-) – Drill and commission Well 7