Important Information for All

Monday, July 27, 2015

Picnic and AGM

It’s almost time for another day of tradition and memory making at the OLRA Annual Picnic.  Join us Sunday, August 2, 12:00 noon at Orr Lake Park for an afternoon to remember as you meet or reunite with neighbours and friends. Games and races provide fun for all ages, as well as scrapbook-worthy medals and ribbons, and great prizes too.  We'll have the BBQ fired up and coolers stocked with refreshments at ridiculously reasonable prices.  All OLRA members and their families are invited.  Annual memberships will be available for the low cost of $10 per household, so if you haven't purchased yours yet don't miss this opportunity to enjoy the day, and reap all the year-long benefits too!

Get creative this week and enter the boat decorating contest.  The theme this year is pirate ships, so break out the Jolly Roger and give it your all.  Or perhaps your artistic talents lean more toward the musical.  Put on your dancing shoes and enter the lip sync contest instead. 

The following weekend, be sure to attend our Annual General Meeting at Orr Lake Golf Club Sunday, August at 1:00 pm.  It’s your chance to hear what the OLRA has done for you during the year, and to voice your concerns. There are several executive positions up for election this year, and we are in desperate need of reliable, conscientious people to fill those roles.  Please consider throwing your hat into the ring, or nominating someone that you believe would serve our community fairly and objectively.  If you are unable to attend the meeting, you can still volunteer by contacting us at olra@live.com.  We realize that we ask for help each year, but it is especially important this year. Without this kind of assistance, it is unlikely that there will be enough resources for the OLRA to continue to be active in the coming year.  We look forward to seeing you there.


We hope that you have been enjoying this beautiful summer, and spend the rest of it safely as you vacation and visit with family and friends.

Sunday, July 12, 2015

Lake Monitoring

The focus of this post is lake monitoring but before we continue along that vein we’d like to take a moment to remind you of the upcoming picnic on August 2 at noon, as well as the AGM on August 9 at 1:00, Orr Lake Golf Club.  If you plan to enter the boat decoration contest, now is the time to start collecting your pirate-y embellishments!  Ditto for working on your choreography for the lip sync contest.   We would also like to offer our thanks to the Bluesteins and Moffitts for their recent donation of prizes to be awarded at the picnic.  Anyone else who wishes to donate new goods or volunteer to assist with races and competitions may contact Susan Eccleshall at 705-725-4120, or email us at olra@live.com.

Orr Lake has been subject to ongoing health monitoring since 2002 through the Ministry of Environment and Climate Change’s (MOECC) Lake Partner Program.  Under this program a dedicated lake resident collects total phosphorus samples and measures water clarity using a Secchi disk to document changes in lake health over time.  The Nottawasaga Valley Conservation Authority has been measuring winter dissolved oxygen (DO) profiles in Orr Lake since 2010.  A late-winter oxygen profile can be viewed as a barometer of winter length, lake nutrient status and potential stress on lake ecosystems.

Total phosphorus (TP) is an important nutrient in water as it is often the “limiting” factor controlling the growth of plants and algae. Phosphorus levels in water can occur naturally in very low through to very high concentrations, though low to moderate levels are more common.  Problematic levels of phosphorus occur when these natural levels are enriched by human inputs which may lead to excessive plant and algae growth. This excessive growth can cause problems such as restricted recreational uses and aesthetic concerns, as well as oxygen depletion resulting in fish kills.

Orr Lake is a mesotrophic lake suggesting its nutrient levels would naturally be elevated when compared to the nutrient-poor (oligotrophic) lakes of the Canadian Shield.  Phosphorus concentrations in a densely populated lake like Orr Lake will increase from septic systems, lawn maintenance (fertilizers, pesticides), and soaps that drain into the lake.  Phosphorus levels can be reduced by plant uptake and binding to lake sediments - maintaining natural shorelines is a key tool to offset potential phosphorus impacts.  The MOECC Provincial Water Quality Objective for phosphorus in lakes is 0.02 mg/L.  Orr Lake has consistently been below the standard.  2014 results show the first occurrence where phosphorus levels exceed the Provincial standard (0.024 mg/L in one sample).  Further monitoring is needed in order to determine if this elevated level is part of a trend or merely a one-time occurrence.

Secchi depth is measured with a Secchi disk, a circular plate with a rope through the middle which is divided into quarters bearing black and white coloured sections.  The disk is lowered into water until it is no long visible and a measurement is taken at this point.  High readings indicate that the water is relatively clear and not turbid, whereas lower readings indicate turbid or coloured water.  In general, turbidity and the presence of colour (algae) are indicative of high lake productivity and clearer water is indicative of lower lake productivity.  The Secchi disk reading for 2014 was not provided by the MOECC.

Dissolved oxygen is referred to as the amount of free oxygen dissolved in the water.  It is required in water to allow fish, insects and other aquatic life to breath and survive.  Tolerant warm water game fish can live comfortably in waters with DO concentrations above 3 mg/L, becoming stressed and perishing at levels below 3 mg/L.  During the summer dissolved oxygen is created by aquatic plants releasing oxygen into the water using photosynthesis, as well as wave-action which physically mixes atmospheric oxygen into water.  As the fall and winter approach, these plants die, start to decompose and deplete the dissolved oxygen levels in the water column.  Persistent ice cover during the winter prevents the addition of dissolved oxygen. Monitoring late-winter oxygen levels over time is important to identify potential stresses to the lake ecosystem and associated long-term trends.

The NVCA has been measuring late-winter DO since 2010 on Orr Lake.  Despite it being one of the coldest winters on record, 2014 results mirror previous years with an oxygen sag starting around 2m depth, stressful conditions begin around 2.25m and near anoxia deeper than 2.5m.  The NVCA did not anticipate any significant fish-kill this spring.

For more info, contact Ian Ockenden of the NVCA by phone at (705) 424-1479 x234 or email iockenden@nvca.on.ca.