08/09/2023 - Packet
WATER ADVISORY BOARD AGENDA – August 9, 2023
City of Tigard | 8777 SW Burnham St., Tigard, OR 97223 | 503-718-2688 | www.tigard-or.gov | Page 1 of 2
City of Tigard Water Advisory Board Agenda
SERVING TIGARD WATER SERVICE AREA
MEETING DATE: Wednesday, August 9, 2023, 5:30 p.m.
MEETING LOCATION: 10 mil Conference Room - PW
Public Dial-in Number for listen-only phone bridge (971) 256-0577
When prompted enter Conference ID 13125
1. Call to Order, Roll Call, and Introductions
2. Approval of Minutes – April 12, 2023
Action: Motion to approve the April 12, 2023, minutes.
3. Public Comments
Call for comments from the public.
4. Water Supply Update – Sammy Rico
5. WAB Q&A - Brian
6. Non-Agenda Items
Call for non-agenda items from the board.
7. Next Meeting
October 11, 2023
Location: 10 mil PW
Time: 5:30 pm
8. Adjournment
Action: Motion for adjournment.
WATER ADVISORY BOARD AGENDA – August 9, 2023
City of Tigard | 8777 SW Burnham St., Tigard, OR 97223 | 503-718-2688 | www.tigard-or.gov | Page 2 of 2
The City of Tigard tries to make all reasonable modifications to ensure that people with disabilities have an equal
opportunity to participate in all city meetings.
Upon request, the city will do its best to arrange for the following services/equipment:
Assistive listening devices.
Qualified sign language interpreters.
Qualified bilingual interpreters.
Because the city may need to hire outside service providers or arrange for specialized equipment, those requesting
services/equipment should do so as far in advance as possible, but no later than 3 city workdays prior to the meeting.
To make a request, call 503-718-2591 (voice) or 503-684-2772 (TDD - Telecommunications Devices for the Deaf).
Executive Session
The Water Advisory Board may go into Executive Session. If an Executive Session is called to order, the
appropriate ORS citation will be announced identifying the applicable statute. All discussions are confidential
and those present may disclose nothing from the Session. Representatives of the news media are allowed to
attend Executive Sessions, as provided by ORS 192.660(4), but must not disclose any information discussed.
No Executive Session may be held for the purpose of taking any final action or making any final decision.
Executive Sessions are closed to the public.
Water Advisory Board Water Supply Update
April 2023 Update
Tigard Usage
Current
(Apr 23)
Prior Yr
(Apr 22)
Avg Daily Use (MGD)4.39 4.03
Avg Temp 59°58°
Peak Use (MGD)4.91 4.46
Peak Temp 88°75°
Tigard Storage
Stored Water (ASR)365.5 334.1
Days of Supply 203.5 182.7
4.39
Average
4.29
0
1
2
3
4
5
6
Average Daily Demand (ADD)
0
20
40
60
80
100
120
140
0
2
4
6
8
10
12
14
Jul 2020Aug 2020Sep 2020Oct 2020Nov 2020Dec 2020Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
April Usage
Average daily water use for the month of April was 4.39
million gallons per day (mgd). Peak daily use was 4.91 mgd.
Last year, average daily water use was 4.03 mgd for the same
time period, with a peak day of 4.46 mgd. Average daily use
for April was above the historic average of 4.29 mgd, but
peak demand was below the historic average of 4.96 mgd for
the month.
4.91Peak4.96
0
1
2
3
4
5
6
7
8
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(Apr 23)
Prior Yr
(Apr 22)
Chlorine Residual 1.12 1.11
Alkalinity 21.05 21.32
pH 8.03 7.94
Temperature 8.90 9.42
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.12 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 21.05 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 8.03
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:8.90C
(48F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
7.6
Average, 8.7
0.0
2.0
4.0
6.0
8.0
10.0
12.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
5906.0Average, 5,159
0
2,000
4,000
6,000
8,000
10,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.5
7.0
7.2
7.4
7.6
7.8
8.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
3.8Average, 3.0
0.0
2.0
4.0
6.0
8.0
10.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Temperature of Clackamas River (c)
Water Advisory Board Water Supply Update
May 2023 Update
Tigard Usage
Current
(May 23)
Prior Yr
(May 22)
Avg Daily Use (MGD)6.83 4.49
Avg Temp 75°65°
Peak Use (MGD)9.21 5.00
Peak Temp 93°78°
Tigard Storage
Stored Water (ASR)364.1 336.3
Days of Supply 202.8 183.8
6.83Average
5.44
0
1
2
3
4
5
6
7
8
Average Daily Demand (ADD)
0
20
40
60
80
100
120
140
0
2
4
6
8
10
12
14
Jul 2020Aug 2020Sep 2020Oct 2020Nov 2020Dec 2020Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023May 2023TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
May Usage
Average daily water use for the month of May was 6.83
million gallons per day (mgd). Peak daily use was 9.21 mgd.
Last year, average daily water use was 4.49 mgd for the same
time period, with a peak day of 5.00 mgd. We experienced
uncharacteristically high temperatures in May. Both the
average daily use and peak use for April were above the
historic averages of 5.44 mgd and 7.15 mgd respectively.
9.21
Peak 7.15
0
2
4
6
8
10
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(May 23)
Prior Yr
(May 22)
Chlorine Residual 1.17 1.07
Alkalinity 19.49 20.37
pH 7.79 7.84
Temperature 12.57 10.97
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023May 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.17 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 19.49 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 7.79
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:12.6C
(55F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
11.0
Average, 11.8
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
4690.0Average, 3,618
0
2,000
4,000
6,000
8,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.6
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
8.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
1.7
Average, 1.7
0.0
1.0
2.0
3.0
4.0
5.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Temperature of Clackamas River (c)
Water Advisory Board Water Supply Update
June 2023 Update
Tigard Usage
Current
(Jun 23)
Prior Yr
(Jun 22)
Avg Daily Use (MGD)8.96 5.84
Avg Temp 78°74°
Peak Use (MGD)10.37 9.18
Peak Temp 92°99°
Tigard Storage
Stored Water (ASR)364.1 336.1
Days of Supply 202.8 183.7
8.96Average
7.17
0
2
4
6
8
10
Average Daily Demand (ADD)
0
20
40
60
80
100
120
140
0
2
4
6
8
10
12
14
Jul 2020Aug 2020Sep 2020Oct 2020Nov 2020Dec 2020Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023May 2023Jun 2023TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
June Usage
Average daily water use for the month of June was 8.96
million gallons per day (mgd). Peak daily use was 10.37 mgd.
Last year, average daily water use was 5.84 mgd for the same
time period, with a peak day of 9.18 mgd. We experienced
high temperatures in June. Both the average daily use and
peak use for June were above the historic averages of 7.17
mgd and 9.10 mgd respectively.
10.37Peak9.10
0
2
4
6
8
10
12
14
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(Jun 23)
Prior Yr
(Jun 22)
Chlorine Residual 1.13 1.10
Alkalinity 26.78 21.25
pH 7.79 7.87
Temperature 17.52 14.17
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023May 2023Jun 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.13 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 26.78 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 7.79
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:17.5C
(63F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
16.8Average, 15.8
0.0
5.0
10.0
15.0
20.0
25.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
1413.5
Average, 2,159
0
1,000
2,000
3,000
4,000
5,000
6,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.7
7.0
7.2
7.4
7.6
7.8
8.0
8.2
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
1.0
Average, 1.5
0.0
1.0
2.0
3.0
4.0
5.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Temperature of Clackamas River (c)
Water Advisory Board Water Supply Update
July 2023 Update
Tigard Usage
Current
(Jul 23)
Prior Yr
(Jul 22)
Avg Daily Use (MGD)10.39 9.72
Avg Temp 86°86°
Peak Use (MGD)11.22 11.64
Peak Temp 98°102°
Tigard Storage
Stored Water (ASR)364.1 336.1
Days of Supply 202.8 183.7
10.39Average
9.23
0
2
4
6
8
10
12
Average Daily Demand (ADD)
0
20
40
60
80
100
120
0
2
4
6
8
10
12
14
TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
July Usage
Average daily water use for the month of July was 10.39
million gallons per day (mgd). Peak daily use was 11.22 mgd.
Last year, average daily water use was 9.72 mgd for the same
time period, with a peak day of 11.64 mgd. Both the average
daily use and peak use for July were above the historic
averages of 9.23 mgd and 10.52 mgd respectively.
11.22Peak10.52
0
2
4
6
8
10
12
14
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(Jul 23)
Prior Yr
(Jul 22)
Chlorine Residual 1.06 1.09
Alkalinity 31.71 28.84
pH 7.77 8.07
Temperature 21.85 19.81
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Apr 2023May 2023Jun 2023Jul 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.06 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 31.71 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 7.77
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:21.9C
(71F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
21.3Average, 19.7
0.0
5.0
10.0
15.0
20.0
25.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
834.0
Average, 1,113
0
500
1,000
1,500
2,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.8
7.2
7.4
7.6
7.8
8.0
8.2
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
1.1Average, 0.8
0.0
0.5
1.0
1.5
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Jul
2023
Temperature of Clackamas River (c)