Enough Studying Water Under a Microscope Already!

April 1, 2022…no fooling.

Open letter to the Board of Directors North Salt Spring Waterworks District

I attended the Board meeting yesterday (March 31, 2022) and listened to the discussion of the engineering reports.

The  “Purpose and Scope” of the May 2021 update report by Kerrr Wood Leidel was as follows:

The objectives of this study were to:

  1. validate existing monthly hydrological model using available recorded climate, lake level, Rippon Creek flow, diversion flow, demand, and outflow data;
  2. re-run monthly water balance/water yield assessment using continuous ~100-year historical climate record to assess multi-year drought risk; and
  3. determine reliable yield of watershed to support water supply at Maxwell Lake under both current and future (2050s) projected climate change conditions.

6.1 Summary and Conclusions

Finding from the assessment of water availability and withdrawal within the Maxwell Lake watershed can be summarized as follows:

  1. Maxwell Lake has a surface area of about 0.302 km2 and lies within a 1.063 km2 watershed.
  2. Rippon Creek and Larmour Creek, which have a total combined watershed area of 1.054 km2 , can be diverted into Maxwell Lake during the period from November 1 to March 31. The licenced diversion limit for this period is 448,812 m3 .
  3. Climate records from the St. Mary Lake climate station indicate that average total annual precipitation for the 1981 to 2010 climate normal period is 987 mm, with approximately 80% of the annual precipitation falling in the six-month period from October to March.
  4. Maxwell Lake only supports waterworks withdrawals for NSSWD as there are no licenced requirements for minimum conservation flows downstream in Maxwell Creek.
  5. A dam and spillway structure at the outlet of Maxwell Lake, which is owned and operated by NSWWD stores approximately 819,000 m3 at the spillway crest elevation of 314.86 m above geodetic survey datum. The total licenced storage volume for Maxwell Lake is 628,830 m3 .
  6. NSWWD currently withdraws about 258,870 m3 /year from Maxwell Lake on average (2010-2020).
  7. Total annual licenced water withdrawal limit for Maxwell Lake is 663,729 m3 (1,818 m3 /day average).
  8. Under current climate conditions Maxwell Lake can support up to 53.5% of the licenced maximum withdrawal without reaching zero storage over the 105-year record modelled in this study. This indicates that the lake is over-allocated and cannot support its full licence withdrawal volume reliably.
  9. Under current climate conditions Maxwell Lake can support up to 53% of the licenced maximum withdrawal without falling below a Stage 3 Drought demand reserve storage, over the 105-year record modelled in this study. 1
  10. Rippon Creek diversion is an important component of the reliability of the Maxwell Lake water supply; increasing the monthly diversion from 50% to 80% of the monthly Rippon Creek flow increases the amount of water that Maxwell Lake can support from 53.5% to 60% of the licenced maximum withdrawal limit.
  11.  Future climate conditions could result in increased winter precipitation to Maxwell Lake, which would increase the net inflows to the lake. This could potentially aid in the water storage reliability of Maxwell Lake if water could be diverted from Rippon Creek with no water quality issues; however more intense rainfall events under a climate change condition may cause turbidity issues

Yesterday KWL stated that the new Maxwell treatment plant will take care of any turbidity challenges, thereby potentially increasing the amount of withdrawal to 60%.

Regardless, 53% is KWL’s lowest recommendation.

Using 53% of 663,729 m3 = 351,776 m3. We are currently (2018 and 2019) using just 215,000-216,000 m3 per year, leaving an available difference of 135,776 m3 = 29,866,544 gallons per year. That is the CONSERVATIVE approach, using a worst case, 1 in 100 year scenario, AND, not really taking into account any increase in winter rainfall which is predicted, or any increase from Rippon Creek and therefore would likely fill the lake in every one of the 100 years.

The following questions were not asked of KWL yesterday:

1. Has any of their 2021 Maxwell Hydrology Update report data been changed since the report was initially brought to the Board in May of last year? E.g. has the recapture of the 2014 leak stoppage (which was never evidently reported to KWL prior to the publication of their 2015 Report) been formally recognized by them yet. If not, why not? (This leak, about 63,000 m3 is the equivalent of about 30% of the entire 2018 and 2019 withdrawal and therefore greatly affects averaging, if any pre-2015 data is used (as it was in the 2021 initial update Report).

On page 6-1 (6) of the report (as shown above) it states “NSWWD currently withdraws about 258,870 m3 /year from Maxwell Lake on average (2010-2020).

This is not accurate. The annual withdrawal, as shown on page 3-2, for the years 2018 and 2019 show a total of 215,000 (114+101) and 216,000 (111 and 115)m3. The reason for the 45,000 m3 difference is that pre-2015 years were used in the averaging….the time during which the 63,000 m3 leak was occurring.

I have previously asked KWL if NSSWD staff ever informed them of the leak stoppage (which was reported by staff to the Board in December 2014). Neither they, nor the Board, have ever addressed this question.

And yet, the misinformation still exists in the updated report….unquestioned by the Board. Why?

2. Has there been any change to KWL’s 2021 recommended 53% of license withdrawal?

3. If not, what is the rationale behind the Board NOT immediately acting to remove the moratorium? (There is a 30 million+ gallon/year excess supply which is not being used below the 53% level.)

4.  Given the above projections and data, what is still in question? What is the “risk” that the Board is worried about that has not already been addressed by the updated Report? Climate change has been addressed, volume has been addressed, input has been addressed, output has been addressed. Percent of license which should not be exceeded has now been well established, and, there is even an indication that the inflow could actually be increased from Rippon Creek once the new plant is constructed.

My Conclusions

While the Board is not a land use planning authority, I believe it has a duty to the Ratepayers to ensure that their FINANCIAL interests are protected…at 30,000,000 available gallons per year, it equals, (using NSSWD’s average of 118 gallons per day per Single Family Dwelling) enough water for nearly 700 dwellings.

I am going to suggest the lifting the moratorium now is rational, given (a) the dire need for housing in the Ganges Area, and (b) the lack of any significant, UNUSED density in the Ganges Area.

Currently the CRD estimates Salt Spring is DEFICIENT in over 600 homes. If, as an illustrative example, NSSWD supplied water to 600 homes, that would create CEC charges of about $6,000,000, with ongoing revenue from taxes and water usage.

Ratepayers are facing massive increases in costs of infrastructure shortly, with no CEC recapture of potential new development.

Enough studying already….its been 8 YEARS since a moratorium that should never have been introduced has blocked affordable housing on Salt Spring.

It is far beyond time for the Board to take action….Quit studying water under a microscope and open your eyes to what the updated report actually says – there’s 30 million gallons safely available that even a six year old can see.

You know…six year olds who are part of young families on the island who actually want to grow up here and live in a decent house…just like you all do.