On the back of favourable weather conditions as a result of La Niña, Algae levels have continued to remain low through winter into spring. Typically a spike in Algae has occurred during this time. It is too early to see any positive effects from the Phoslock Treatment in August but water clarity has definitely improved.
Griffith University have indicated groundwater as a significant source of saline inflow. Although impossible to measure the extent or even the concentration of any groundwater, ongoing in-lake measurements clearly indicate substantial inflows of salt from the canal having an impact. See diagram.
At the recent meeting with Council, the Care Group requested investigation into all inputs into the lake and to clarify the readings that indicate this salt input. Regardless of where the salt is coming from, the increasing trend in salt means more salt is entering the lake than exiting. Reducing a major input of salt from the canal has the potential to reduce the overall salt content of the lake and reduce stratification and lake decline.
The Griffith report 3 years ago highlighted the need for further information stating;
“More information on inflows is needed, both in terms of nutrient concentrations and volumes of water input from the storm water drains, as well as exchange of groundwater and/or the adjacent canal. An understanding of the source of the higher salinity water accumulating in the lake bottom is needed.”
Unfortunately 3 years on, Council has not taken steps to investigate and provide the necessary information/monitoring to determine the detrimental effects from the canal.
The key questions are;
How can Griffith make a determination of significant groundwater without even assessing input from the canal in both tidal and rain events?
Are Council planning to effectively monitor salt, flow and nutrients from the canal to assist in this determination?
The Care Group will advise on the reply once received.
The options report is now available on the Council Website. Link included below.
The key to any report is the follow-up with action to address the key issues affecting the long term health of the lake. The Care Group will be looking forward to the plan to implement the best options to address the ongoing trend of increasing stratification and increasing salt that is has been a major contributor to the decline in water quality.
The one way valve did not score as well as expected – Alluvium only had medium confidence in their assessment given the minimal evidence and no modelling. Despite the significant influence the canal input has on both the salt and nutrient levels, there has been no assessment, investigation or modelling to determine how this input effects the lake.
Given the importance, the Care Group request that proper investigation including modelling be carried out on canal input.
With Spring just around the corner, now is a great time to get in a do some overdue maintenance to your garden to reduce green waste from entering the lake.
Council have a FREE service called Flexiskip where they will supply a skip to remove household rubbish including green waste.
This is a great opportunity for waterfront residents to dispose of any waste lakeside and for residents in the catchment to remove any leaf litter, weeds, excess lawn clippings etc that can find their way into the lake.
Please follow the link below for full info and to order your skip!
Just a brief update on the meeting held on the 12th of August.
Poor attendance from user groups with only one other representative from tri clubs present.
No commitment to Phoslock top up until assessment of initial treatment.
Reedbed removal shortly due to age /structural issues. Care Group recommend replacement habitat established BEFORE removal to reduce impact to wildlife.
Planting of foreshore plants adjacent to parklands with existing species planned by Council. This will provide habitat but delays to supply/grow mature plants, then establishment.
Presentation of Options report. Options are scored on various criteria. Phoslock and submerged aquatic plants rated highly with one-way value down the list due to no modelling done and the indication by Griffith of significant saline groundwater intrusion. The Care Group are still waiting for clarification on the assessment of salt and nutrient inputs from the canal vs groundwater.
Option of mixing waters near lake exit during rain events missing from assessment. Option can assist in removal of both nutrient and salt water from the lake. Request that consideration and analysis be included.
Only one option to resolve stratification that scored highly on both environmental and social criteria. The option involves shallowing of the west side of the lake to induce natural cycling of the water column as is the case with the eastern side of the lake. See image for clarification – Image courtesy of Princeton Hydro.
Options report used to develop a lake management plan but no timeframe.
Digital copy of options report to be available on Councils website shortly.
On further analysis of the option report, the Care Group will be following up with numerous questions to clarify the assessment of options and Councils current/future plan to stop the decline.
The Phoslock application has now been completed. This treatment along with sand capping was recommended by Griffith Uni as the best option to reduce the occurrence of algal blooms.
It does not however, resolve the serious lake health issues that resulted in an ongoing decline in lake health for over 20 years.
A meeting with Council scheduled in 3 weeks, COVID permitting will discuss the options to best address the long term health issues including increasing stratification and increasing salt that has resulted in a significant decline in aquatic vegetation.
Clr Pauline Young has announced on FB today that LHM will be receiving a Phoslock treatment this spring. This is great news that Council are taking remedial action to address the significant and rapid decline while investigating options to address the key lake health issues that have led to the decline.
There is no guarantee of success with this treatment. The effectiveness of this treatment is dependent on timely implementation of other key options to minimise nutrient inputs into the lake including action on lake health.
A meeting has been arranged by Council on the 12th of August to discuss the key options and will advise on outcome.
In a recent story in the Bulletin Clr Young describes the Lake Hugh Muntz Community who attended the meeting as
“a 200-strong mob just going off at me” and
“thank God there were council security officers there, it was terrifying”
The Care Group would like to clarify that at this community meeting there were no threats, no abuse and no unacceptable behaviour towards Councillor Young or any other participants.
There were members of the community rightfully expressing dissatisfaction over the appalling decline of LHM, highlighting that after 5 years of closures, there is still no timeline and no funded action plan. The photo taken this summer highlights the genuine concern by the community.
Please review the Council Community Information video on LHM YouTube site below and while there, have a look at what the lake used to look like.
The care group requested Council fast track feasibility and implementation of Griffith recommendations based on;
This Scientific research offer the best solution to reduce algae.
Council and Alluvium consultants confirming at the meeting in December that the lake is on a rapid decline and urgent action is required.
The inability of Council to provide any indication or estimate of timeline for funded action – possibly years before action!
Councillor Young advised that;
The City continues to commission, receive and analyse complex scientific data about this lake and algal blooms. When a remedial option that is deemed viable, is supported by scientific research and is affordable with strong prospects for success, there will be no hesitation in attempting resolution.
The Engineering dept has the opportunity to restore public confidence and provide information on what tests are being done, the timeframe and an estimate to implementing a funded solution but to-date have ignored requests.
At the recent information session, despite 5 consecutive years of closure, 9 months since release of Griffith Recommendations and 6 months into the feasibility study, Council were unable to provide any info on timeline leading to unnecessary frustration, dismay and anger from the public.
With the last update now a year out of date the Care Group once again are forced to escalate to our elected representative, Pauling Young to get the updates.