CLARION
A Publication of the Colorado Lake and Reservoir Management Association
Colorado Lake and Reservoir Management Association
P.O. Box 9504 Denver, CO 80209
www.clrma.org
Growing up, I spent a fair amount of time recreating in and around various
lakes and reservoirs in northwestern Colorado. I have fond memories of fishing
at, wading in, boating on and hiking to several lakes and reservoirs in the area. Later, I realized that some of
these bodies of water were not just there for us to visit but were used to irrigate, supply cities and towns and
generate power. July is Lake and Reservoir appreciation month, so let us all remember that especially in
Colorado, Lakes and Reservoirs are an important part of our lives. In light of this, I highly recommend
spending some quality time with those you love at the lake or reservoir of your choice this summer.
President’s Dock
We at CLRMA are busy putting together Day at the Reservoir (or Lake), at Ferril Lake in City Park on July
20th, where we will explore urban lake issues. We are also starting the planning for our Fall Conference,
which has been set for October 25th in Westminster. Also, we are starting to plan for the 2017 NALMS Symposium. We would love to hear your ideas for
the theme, logo, special session topics, and keynote speakers, so please pass them along, one way to do so is
via email to [email protected].
Hope to see you all on July 20th at City Park!
Cindy Brady, CLRMA President
In this issue:
Arvada Reservoir Two Years After the Flood - 2
2017 NALMS Symposium Planning Update - 2
CLRMA 2016 Day at the Reservoir Flyer
- 3
Day at the Reservoir Registration Form
- 4
Barr Lake Lend a Hand for Your Lakes & Land - 6
2016 Secchi Dip in Goal & May Challenge Winner - 7
Hahns
Peak Lake
2017 NALMS Symposium Advertising
- 8
2016 Secchi Dip –In Information
- 10
Lake Appreciation Month Information
- 11–12
PAGE 2
Arvada Reservoir - Two Years After the Flood
CLARION
By Kevin Tohill
Over two and a half years have passed since record floods impacted reservoirs and streams along Colorado’s
Front Range in September of 2013. While the majority of the damage to infrastructure has been repaired and
operations related to water supply, recreation and flood control are returning to normal, some of the longterm effects are still progressing.
At Arvada Reservoir, we are observing changes in water quality and trying to anticipate what these changes
might mean for the future of the reservoir as a drinking water source. Although the changes have been minor
so far and the data set collected since the flood is relatively small, it is clear that impacts from flooding do
have potential to affect water treatment operations.
After the flood, Arvada hired Steve Klein and Telesto Inc. to conduct a sediment study to determine how
much sediment was carried into the reservoir by the flood and what the sediment contained. It was estimated
that about 1,000,000 kg of sediment was deposited in the hypolimnion, including 1000 kg of manganese,
2370 kg of nitrogen, and 760 kg of phosphorus. A hydroxylamine hydrochloride extraction intended to simulate anoxic release from the sediment estimated that 86% of manganese, 15% of iron and 36% of phosphorus
could feed back into the water column from the sediment.
Unfortunately, Arvada never studied sediment in the reservoir before the flood so it is not known how these
results compare to existing pre-flood sediment. Nonetheless, it was expected that the constituents mentioned
above would have some impact on water quality as microbial processes and reduction under anoxic conditions make them soluble over time.
(Continues on Page 5)
NALMS Symposium Planning Update
The Host Committee met after the spring luncheon and worked on the logo and the theme for 2017. The
theme that was selected is, “Finding Balance”. This is a great theme for Colorado. We need to find balance
with many different aspects of lake and reservoir management. As soon as a location is determined, we will
send out the dates and other details as they are finalized. The logo for the Symposium is below:
If you want to help out in any way, please consider one of these planning sub-committees.
Exhibitors – recruit companies and groups to come as exhibitors
Fundraising – recruit companies and people to sponsor the event
Program – develop the schedule of topics, speakers, and presenters
Volunteers – work with local students to help work at the event
Publicity – advertise as much as possible to boost attendance
Local Arrangements – organize the social events during the symposium
PAGE 3
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Colorado Volunteer Lake Monitoring Program
Welcome goes out to our newest volunteers, Vic Lucero (Walsenburg, CO) and Tami Bishop
(Denver, CO). Vic will be monitoring two lakes in Lathrop State Park. Tami will be monitoring a series of 4 reservoirs along Clear Creek downstream of Golden, CO.
Thank you for signing up and have a great summer collecting water clarity data!
CLARION
PAGE 4
Registration Form
2016 Day on the Reservoir
(in this case Lake)
Where: Denver City Park Pavilion Plaza
1700 N York Street,
Denver, CO 80202
Date: Wednesday, July 20, 2016
Time: 10:00 am – 2:30 pm (Registration 9:30-10:00 am)
Cost:
I am a lake volunteer (Free)
I am a student member ($10)
I am a CLRMA member ($35)
I am not a CLRMA member ($45)
Name:
Affiliation:
Address:
Phone:
FAX:
Email:
Dietary needs (e.g. vegetarian, gluten free, allergies)
_________________________________
Please check here if new information.
Donate to the CLRMA Scholarship Fund $
If interested in exhibiting at this event please email Cindy Brady at
[email protected].
---------------------------------------------------------------
Please send registration form and check(s) to: CLRMA, P. O. Box 9504,
Denver CO 80209 Attn: Laurie Rink or by credit card on the web:
www.clrma.org click on the News/Events tab.
A limited number of scholarships are available: See our scholarship application on line at:
www.CLRMA.org under the Events tab.
PAGE 5
CLARION
In the two years since the flood, Arvada has collected enough sampling data to reveal some changes in water
quality that are presumably related to sediment deposition that occurred during and after the flood.
Increases in total nitrogen, total phosphorus and manganese have been observed, as would be expected considering the amount of these elements were deposited in the hypolimnion. What is interesting is that the
changes that have occurred seem to reveal that the most influential mechanism on nutrient concentrations in
the water column may be related to reduction of sediment that has settled to the bottom of the reservoir,
more so than direct nutrient inputs from inflows to the reservoir.
From 2000 to one week prior to the flood in 2013, water column nutrients were trending downward, as
shown in the graph of annual average nutrient data below:
Ekman grab sample
Figure 1: Pre- Flood Annual Average Total Nitrogen and Total Phosphorus
Core from Ekman grab
Including post-flood data reverses the slope of the trend lines:
Figure 2: Post-Flood Annual Average Total Nitrogen and Total Phosphorus
(Continues on Page 7)
Piston Core Sample
PAGE 6
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PAGE 7
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You may notice that the line for phosphorus in figure 2 is relatively flat in 2014 and isn’t much higher than
historic values. The graph below shows one possible explanation:
Figure 3: Dissolved oxygen and Total Phosphorus concentrations at 15 meters
Evidently, late summer anoxia did not result in as much phosphorus release in 2014 as it did in 2015. It is
possible that microbial processes had not yet reduced phosphorus to the point where it was released under
anoxic conditions. Additionally, sediment sampling after the flood indicated that the sediment deposited by
the flood was highly oxidized and more than one season of anoxic conditions may have been required for
phosphorus release to occur. (Continues on Page 9)
Help Us Meet the 2016 Secchi Dip In Goal for Colorado
Get ready for this year’s Dip In. The goal is to send in 50 Secchi depth readings to the Dip In during the
month of July.
If you collect a Secchi depth reading in July, please take a few minutes to send it the data to the Dip In website. It is easy to do and it can help show how Colorado stands up to other regions of the country when it
comes to water clarity in July.
The website is http://www.secchidipin.org/. If you have troubles or any questions, contact Steve Lundt
([email protected]).
Arvada Reservoir (barely) Wins May Secchi Depth Challenge
On May 27th, 2016 the Secchi depth at Arvada Reservoir was 4.8 meters, narrowly edging out the next-highest reading reported, 4.35 meters at Milton Reservoir. If you have
been reading the article on flood impacts, you might be wondering how Arvada Reservoir
had the deepest reading. Frankly, so are we. There have to be reservoirs getting deeper
Secchi depths, report yours next year and show how great some of Colorado’s lakes are!
PAGE 8
CLARION
Get Great Exposure by Sponsoring the 2017 NALMS Symposium
It will be a great opportunity in 2017 to advertise during the annual symposium that will be hosted here in
the Denver area. There are several opportunities and various sponsorship levels for CLRMA members to
choose from that will reach out to over 500 attendees. Non-members are welcome to sponsor as well.
If you are interested in being a sponsor in the fall of 2017, now is the time to plan. Please contact Laurie
Rink, the chair of the Fundraising committee ([email protected]).
Sunset at Barr Lake, Steve Lundt
Websites of the Month –
www.boatsafe.com/nauticalknowhow/safetips.htm
It is always important to be fully educated on boat safety. Make sure you wear a flotation device, have a
throw rope in the boat, a working fire extinguisher, a whistle, and make sure your boat is properly working.
Be safe out there this summer.
http://nalms.gravitymail.com/cp/170148C0d860d699d7d1a8c206bfb331cdf3716
Link to the most recent NALMS newsletter for May/June.
CLARION
PAGE 9
Interestingly, when comparing Pearson correlation coefficients between photic zone phosphorus and inflow
sources, no strong correlations were revealed, but some of the strongest correlations showed an inverse relationship between dissolved oxygen and total phosphorus.
Additionally, the correlation between phosphorus at 15 meters and photic zone phosphorus is stronger than
phosphorus correlations between inflow sources and the photic zone. Although the correlations aren’t strong,
they seem to indicate the release of phosphorus from the photic zone has a stronger influence on overall photic zone levels than phosphorus from inflow sources. Keep in mind that the data set for 15 meter samples is
small compared to inflow sources, time will tell if the correlations become stronger as more data is collected.
Correlations for nitrogen are stronger between inflow sources and the photic zone than those between the 15
meter samples and the photic zone. This is probably because the majority of nitrogen enters the reservoir as
dissolved nitrogen and remains mixed throughout the water column as water travels from inflow sources to
the photic zone sampling point. Pearson correlations for TSS vs Nitrogen and Phosphorus seem to support
this for the Croke Canal and Church Ditch.
Pearson Correlations
Data Compared
Data Period
Data Type
Photic Zone /15 Meters
Photic Zone /15 Meters
Photic Zone/15 Meters
2014-2015
2014-2015
2014-2015
discrete
discrete
discrete
Photic Zone /15 Meters
2014-2015
Ralston Creek/Photic Zone
Ralston Creek/Photic Zone
Church Ditch/Photic Zone
Church Ditch/Photic Zone
Croke Canal/Photic Zone
Croke Canal/Photic Zone
Ralston Loading/Photic Zone
2000-2015
2000-2015
2000-2015
2000-2015
2000-2015
2000-2015
2000-2015
Ralston Loading/Photic Zone
2000-2015
Church Loading/Photic Zone
2000-2015
Church Loading/Photic Zone
2000-2015
Croke Loading/Photic Zone
2000-2015
Croke Loading/Photic Zone
2000-2015
Church Ditch
Church Ditch
Croke Canal
Croke Canal
2000-2015
2000-2015
2000-2015
2000-2015
(Continues on Page 11)
Parameter
r2
40
40
40
Total Phosphorus
Total Nitrogen
DO at 15 Meters vs Photic
Phosphorus
0.31
0.29
-0.34
discrete
40
DO at 15 Meters vs Photic
Nitrogen
-0.31
discrete
discrete
discrete
discrete
discrete
discrete
Monthly
Average
Monthly
Average
Monthly
Average
Monthly
Average
Monthly
Average
Monthly
Average
discrete
discrete
discrete
discrete
270
270
270
270
270
270
154
Total Phosphorus
Total Nitrogen
Total Phosphorus
Total Nitrogen
Total Phosphorus
Total Nitrogen
Total Phosphorus
-0.01
0.32
0.02
-0.07
0.09
-0.02
-0.01
154
Total Nitrogen
154
Total Phosphorus
-0.06
154
Total Nitrogen
-0.03
154
Total Phosphorus
0.02
154
Total Nitrogen
0.18
107
107
160
160
TSS/Total Phosphorus
TSS/Total Nitrogen
TSS/Total Phosphorus
TSS/Total Nitrogen
0.87
0.11
0.77
0.47
# Of Samples
0.34
Secchi Dip-In 2016
Celebrate Lakes Appreciation Month with us!
July 1st - July 31st
Relax by the Water & Take a Dip!
Secchi Dip-In 2016 is approaching quickly and ​
we’d love your help to make it a success​
! Planning to enjoy
time by the lake this summer? A Secchi disk reading ​
takes just a few minutes​
, is a great way to ensure those
waters stay a healthy place to have fun, and is simple enough that ​
everyone can participate​
.
The Dip-In is an international effort in which volunteers produce a “snapshot” of the transparency of water
in the United States and Canada. Secchi disk readings can be submitted online at ​
www.secchidipin.org or
via the Lake Observer mobile app.
Twitter:
@SecchiDipIn
E-mail:
[email protected]
Website:
www.SecchiDipIn.org
© Secchi Dip-In 2016
Sponsored by the North American Lake Management Society (NALMS).
PAGE 11
CLARION
The observations related to phosphorus show a phenomenon that is probably common among most FrontRange reservoirs, where the majority of phosphorus is carried in with suspended sediment and settles to the
bottom before it has a chance to become reactive.
This is important for assessing potential implications of flood deposited sediment because a large amount of
oxidized sediment was deposited in one event. Based on the depth of a sediment core extracted after the
flood, it appears that about 3-5 mm of sediment was deposited annually. Sediment deposited by the flood
was estimated to be between 1-2 cm thick in the hypolimnion, providing more substrate to be reduced, including more phosphorus.
In the short term, there is potential for larger, short-lived increases in phosphorus concentrations leading to
more algae growth. In 2014 and 2015 algae density and biovolume and density did not increase significantly
compared to historical data but shifts in the type and time of occurrence of algae have been observed. Without getting into much detail, blue-green algae have shown up more frequently and earlier than in previous
years. In August, 2015, a taste and odor event related to blue-green algae developed in conjunction with photic zone phosphorus that reached 27 ppb versus a historic monthly average of 10 ppb for August. Interestingly, this occurred about 2 weeks after dissolved oxygen at 15 meters dropped below 1 ppm, anecdotally supporting the assumption that algae growth is responding to sediment feedback. Anabaena counts reached 615
cells/ml in a zooplankton tow on 8/14/2015 then decreased to 2 cells/ml until turnover caused the spike in
phosphorus shown in figure 3 followed by an increase in anabaena to 28 cells/ml.
In the long term, phosphorus releases may decrease as the upper sediment layer is oxidized and reduced during turnover cycles and the phosphorus that is available for release is expended from the sediment. The real
question is how long will this take and what will reservoir conditions be like in the interim.
Although the reservoir’s reaction to the flood may cause difficulties related to water treatment it has presented a unique opportunity to better understand how it processes nutrients. It has also revealed potential new
ways of looking at cycles in the reservoir. Prior to the flood, Arvada never studied the sediment in the hypolimnion. The 2013 study has provided new perspectives on how effects of sediment deposition can be managed.
Since the flood, Arvada started collecting samples 5 meters above the bottom (at 15 meter depths). In addition to highlighting a major mechanism for nutrient processing in the reservoir, data collected at 15 meters
has provided ability to anticipate short-term reactions such as seasonal manganese release. This allows managers and operators to make decisions such as changing to a shallower intake where more dissolved oxygen
is present in order to bring better quality water into the treatment plant and limiting the amount of sediment
that enters the reservoir.
In retrospect, sampling sediment in the hypoliminon and focusing on how it influences photic zone water
quality would have been advantageous, even in times when no water quality problems were apparent.
Special Thanks to Steve Klein, now with Benthica LLC.
Reference: Report on Arvada Reservoir Sediment, Telesto Inc. March, 2014
Lake Appreciation Month - July
July is a great time to go out and have fun on a lake or reservoir. There are plenty of opportunities to enjoy
lakes in Colorado. Many lakes around the state are having lake appreciation events, including Barr Lake,
Cherry Creek Reservoir and Ridgeway Reservoir. You can also participate in the Day on the Rez (July 20),
do your own shoreline clean up, help volunteer at a local park or state park that has a lake or reservoir, or get
more educated about a particular watershed or lake.
Lakes Appreciation Month 2016
Enjoy and help your favorite lake in July!
July 1st - July 31st
From fishing to your daily coffee,
lakes and reservoirs play a vital role in our daily lives. For over 20 years, ​
July has been officially ​
Lakes
Appreciation Month​
. It is a time when many folks are vacationing and enjoying lakes, and NALMS wants
people to give something back. Just think, what would your life be like without lakes?
July ​
is a great time to set aside some time to celebrate and help your favorite waterbody. Here are some
ideas: participate in a local Lake Appreciation event, do a shoreline cleanup, participate in the ​
Secchi Dip-In​
,
go to a new waterbody and explore, take kids fishing, go boating or canoeing, plant trees or restore shoreline
habitat, use ​
phosphorus-free lawn fertilizers, or simply take a few minutes to think about where your water
comes from and what you can do to help protect it. There are many other ideas that can be found at
www.nalms.org​
or ​
www.epa.gov/lakes​
.
Facebook:
NALMS
E-mail:
[email protected]
Twitter:
@NALMStweets
Website:
www.nalms.org
Instagram:
@NALMSphotos
© Lake Appreciation Month 2016
Sponsored by the North American Lake Management Society (NALMS).
WHEREAS, lakes and reservoirs are among Colorado’s most valuable natural resources;
and
WHEREAS, lakes and reservoirs provide drinking water, irrigation, energy, recreation,
scenic beauty, and habitat for wildlife; and
WHEREAS, these beneficial uses have been of vital importance to Colorado’s history,
growth, and financial health; and
WHEREAS, our lakes and reservoirs improve the quality of life for all of Colorado’s
residents and their importance should not go unnoticed; and
WHEREAS, Colorado recognizes the need to protect these lakes and reservoirs for future
generations;
Therefore, I, John W. Hickenlooper, Governor of the entire State of Colorado, do hereby
proclaim, forever after, July, 2016, as
LAKES APPRECIATION MONTH
in the State of Colorado.
GIVEN under my hand and the
Executive Seal of the State of
Colorado, this first day of July, 2016
John W. Hickenlooper
Governor
Colorado Lake and Reservoir Management Association
P.O. Box 9504, Denver, CO 80209
Have an article or advertisement
you would like to publish in the
Clarion?
Contact Kevin Tohill
720-898-7764
[email protected]
www.clrma.org
Or go to: http://www.clrma.org/newsletters.shtml
2016 CLRMA Board of Directors
Title
Name
Email
President
Cindy Brady
[email protected]
President - Elect
Kelly Close
[email protected]
Past President
Elizabeth Brown
[email protected]
Secretary
Paul Tedesco
[email protected]
Treasurer
Laurie Rink
[email protected]
Director at Large
Kelly Cline
[email protected]
Director
Craig Wolf
[email protected]
Director
Andy Cross
[email protected]
Director
Al Polonsky
[email protected]
West Slope Director
Mike Eytel
[email protected]