Report No. ENG 031-2016

Date: May 20, 2016 File No: 5600-60

To: Mayor and Council

COUNCIL REPORT

EXECUTIVE COMMITTEE

From: Subject:

Peter Sparanese, General Manager, Engineering and Regional Utilities Implementation of Stage Two Water Restrictions

RECOMMENDATION

THAT Report No. ENG 031-2016, dated May 20, 2016, from the General Manager, Engineering and Regional Utilities, regarding the Implementation of Stage Two Water Restrictions, be received for information.

SUMMARY OF THE ISSUE

Under the authority of the Waterworks Rates and Regulations Bylaw 2053-2011, Article 32 (1 ), the Engineer can issue an order to implement Stage Two Water Restrictions when the Dickson Lake level falls with the yellow band as shown on the graphic in Attachment "A". Stage Two Water Restrictions restricts lawn sprinkling t9 once a week and other outdoor water using activities as set out in Schedule "E" of the Bylaw.

BACKGROUND

Stage One Water Restrictions were implemented on May 1, 2016, which restricted lawn sprinkling to specified days of the week between the hours of 6:00 a.m. and 8:00 a.m. The lack of significant precipitation in late April and early May along with hot weather causing evaporation and early snow melt, has resulted in the Dickson Lake level dropping as shown in Attachment "B".

DISCUSSION

Stage Two Water Restrictions are triggered when the Dickson Lake level falls within the yellow band shown on the graphic in Attachment "A". Based on the lack of precipitation, hot weather and early snow melt, it is projected that the lake level will drop and enter Stage Two by June 1, 2016. Staff are adjusting system operations and using the groundwater wells more to maintain storage in the lake as much as possible. It is also important to note that while we are recommending to enter Stage two, this will allow the water system to operate under gravity conditions; however, the reservoir has the majority of its capacity under pumping conditions available.

Report No. ENG 031-2016 Page 2 of 2

The water restrictions are necessary to preserve the Dickson Lake water storage. Stage Two restricts lawn sprinkling to once a week and restricts other outdoor water using activities as set out in Schedule "E" of the Waterworks Rates and Regulations Bylaw, such as prohibiting fountains and water features that do not have recirculation systems.

FINANCIAL PLAN IMPLICATION

There is $20,000 for advertising and education for the water restrictions in the 2016 Joint Water Conservation budget.

Date reviewed and approved by the Chief Financial Officer: May 19, 2016.

IMPACTS ON COUNCIL POLICIES, STRATEGIC PLAN AND/OR COUNCIL DIRECTION

Efficient water use supports the City's Strategic Plan of providing a Complete Community through environmentally responsible and sustainable use of resources and ensuring public safety through access to a safe and reliable supply of drinking water.

SUBSTANTIATION OF RECOMMENDATION

In accordance with the Waterworks Rates and Regulations Bylaw 2053-2011 ,Article 32 (1) the Engineer can issue an order to implement Stage Two water restrictions when the Dickson Lake level falls with the yellow band as shown on the graphic in Attachment "A". It is projected that Dickson Lake will enter Stage Two by June 1, 2016. Stage Two water restrictions restrict lawn sprinkling to once a week and other outdoor water using activities as set out in Schedule "E" of the Bylaw.

ATTACHMENTS

Attachment "A": Dickson Lake Level Guideline for Water Shortage Response Plan

Attachment "B": 2016 Dickson Lake Level

Attachment "A"- ENG 031-2016

Dickson Lake Level Guideline for Water Shortage Response Plan

640 .-------------------------------------------------------------------------------.

635

e 63o -Cl> > Cl>

...J ... Cl> -m 3: 625

620

Spillway Level 638.34 m

No Restrictions

Gravity Drawdown Level 632.30 m

-----------------------------

Winter Caution

Water Shortap Respo 111e Plan SIJICes

Stagel Nonnal Stage2 PI'I!Cau tio nary Stage:! Dry

Stage4 Very Dry

Situations Rl!quirinl Spl!tiool Considel'lltion

Summer l:ritital Extremely Dry Winter Caution Lake Level8elow Outiet

Summer

Critical

No Licensed Water Use

Stage 1

St~ ... <>fJ~

,...;.) 7t:i0/d--.

No Restriotions ~ "%"~ "' . ~

~ J

Winter Caution

615+-----,-----,-----~----~----~----~------r-----~----~----~----~----~

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

100%

75%

Q) C)

~ 0 ..... V) .... ~

~ 50% "C

Q) f/) c:: Q) 0 :J C) c:: ·-

25% .5 m E Q)

0:::

0%

Attachment "B" - ENG 031-2016

2016 Dickson Lake Level

640 .--------------------------------------------------------------------------------------------.

635

I 630

Q; > C1)

..J ,_ C1) .... m s: 625

620

Level 638.34 m

Stage 1

- . -.I

Summary of Water Licenses Allowable annual withdrawal- 33,60.0 MUyr (92.1 MLD)

Maximum allowable daily witl').drawal- 141 .5 MLD Storage - 15,90'0 ML

No Licensed Water Use

, I -.

Q) 75%)

~ B (f)

.?:

50%

·~ 25% l5

0%

615 +-----~------~----~------~------~-----r------~----~------~------~-----r----~

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

--- • Gravity Drawdown (632.3 m) - Lake Level - · - · Lake Level (2015) ---Lowest Historic Level (2006)

100%

75% C1) C)

~ .9 t/) ,_

50% '* s: 'C C1) UJ r::::

~ 25% :J

C) r:::: r::::

·ca E C1)

c:::

0%

Gravity discharge from the lake is only available when the lake level is above an elevation of 632.3 m. The significance of the 'Gravity Drawdown ' elevation is that pumping from the lake may be required at certain times of the year, to ensure sufficient flow in Norrish Creek downstream. While a significant amount of the licensed storage volume is below the 'Gravity Drawdown' elevation, pumping of this water would require ongoing operation of pumps, a generator, and re-fueling of the system. Relative to releasing the water by gravity, pumping results in an increased risk and cost for the discharge of water from Dickson Lake. Stages 1 through 4 refer to the AMWSC Water Shortage Response Plan, which outlines watering restrictions and allowable usage based on the status of the water supply system.