Improving Water Quality by...
RETROFITTING EXISTING DETENTION PONDS
Three Lakes Estate Detention PondS
Three Lakes Estate Detention Ponds Improvements
Currently, partners of the Easter Lake Watershed Project are working on completing dredging, shoreline, and habitat work in Easter Lake. In order to improve long term water quality in Easter Lake, it is necessary to reduce as much sediment entering the lake as possible. One part of this effort includes making sure the detention ponds such as those in the Three Lake Estates area and Easter Lake Drive west of SE 27th Court are able to retain as much silt as possible. During construction of homes in this area, a significant amount of silt was deposited in these ponds. At this point in time, a conceptual plan is being developed to improve the stormwater management function of these ponds which will likely include dredging to remove silt from some or all of the ponds.
Detention Ponds in this area have been surveyed and water is being lowered prior to winter. Lowering the water in these ponds serves multiple purposes including:
- Allows for more accurate silt measurements to be estimated for the development of construction plans
- Allows for silt on the bottom of the pond to consolidate
- Helps to dry out the anaerobic silts which will help to control some of the natural odors when these silts are removed through a future construction contract
- Reduces the amount of silt that is deposited into Easter Lake before the ponds are dredged
The conceptual phase study will continue through this spring and will result in specific recommendations to improve the function of the stormwater detention ponds.
As more details become available, a meeting will be held to help you learn more details about the project and schedule and will provide an opportunity for feedback.
The Easter Lake Water Quality Management Plan was completed in 2012 in partnership with the Iowa Department of Natural Resources and Polk County. Currently Polk County is working to complete the dredging of Easter Lake. In order to improve long term water quality in Easter Lake, it is necessary to reduce as much sediment entering Easter Lake as possible. One part of this mitigation effort is to ensure the detention ponds, such as those shown on the map below are able to retain as much silt as possible. During construction of homes in this area, a significant amount of silt was deposited in these ponds. Therefore a conceptual plan is being developed to improve the stormwater management function of these ponds which will likely include dredging to remove silt from some or all of the ponds.
Water in the ponds was lowered fall 2017 and has been surveyed. The conceptual study continued through last winter and we are now asking for public input from the residents living in the area of these stormwater detention ponds. Residents of the surrounding area are invited to a meeting to learn more details about the project and schedule.
On May 16, 2018 at the South Side Library at 6pm a public meeting was held for attendees to learn more about conceptual design plans for city detention basin improvements in the Three Lakes Estates neighborhood area. During the meeting, members from the City of Des Moines and Stanley Consultants presented project information and responded to questions from the public. Attendees of the meeting were encouraged to submit input and feedback.
Below are a variety of materials and information shared during the public meeting including presentation slides, videos (transcripts also included), and project area visuals.
Friday, January 4, 2019 – The Easter Lake South Watershed Pond Dredging Improvements near and around the three lakes estates area has been awarded to the contractor: Elder Corporation in the amount of $1,827,200. The completion date of this work is May 1, 2020. The contractor had intended to start work immediately in early January 2019 with the aid of frost to help stabilize the pond silt, but there is not enough frost and it does not appear that there will be based on the next 10 day forecast and normal Iowa seasonal temperatures. The Elder Corporation is currently planning on draining these ponds in late June 2019 and begin work in July during the normal Iowa hot and dry summer. This of course will be weather dependent and we will provide updates when the Contractor notifies us he is intending to start work.
Mid July, Elder Corporation will begin drawing down water in ponds 3 and 5 (see map). Later in July, dredge material from ponds 3 and 5 will start to be removed. Preparation will begin for a fill site located off of Driftwood Lane near pond 4.
Tree Removal will begin at the south end of pond 3 and southside of pond 4. A haul road will be established from Pine Ave at pond 3 traveling north to a dredge spoil site and additionally a haul road will be established west from pond 4.
Pond 4 will be drained after excavation of overburden soils on the south side of the pond is completed, and after a sediment forebay is constructed on the wend end of pond 4.
Between August and early November significant progress has been made. See below for more details. For questions, please contact Brad Brockman who can be reached at 515-283-4070 or BRBrockman@dmgov.org.
- Basin 4: Complete. Regrading, dredging, and reseeding of banks of this basin was finished in October.
- Basin 3: Significant progress on dredging of this pond was made throughout October. Depending on cooperative weather, work on this pond should be complete in the next coming weeks
- Basin 5: Dewatering of this pond has begun. Once basin 3 is complete, work will begin on basin 5.
Wet conditions throughout October have made construction difficult. However, Elder Corporation will continue to work through the winter to finish major basin improvements and to dredge remaining smaller basins.
The City of Des Moines would like to update residents within the Three Lakes Neighborhood concerning progress and schedule for the Easter Lake South Watershed Pond Dredging and Improvements.
Construction began during the summer of 2019 on Basin 4, west of Three Lakes Parkway and has continued to basins south (Basin 3) and north (Basin 5) of the dam within the development, as shown on the attached exhibit. Material removed from the basins is being placed on City owned property west of the neighborhood.
During construction, the contractor has established a haul route along/over the existing trail east of the basins. The contractor has placed soil over the trail to help prevent damage from large equipment. Once pond dredging has been completed, the contractor will remove the material and City staff will inspect the trail for damages. Any damaged trail will be replaced by the contractor.
The contractor has completed excavation and bank grading within basins 3 and 4. Excavation of basin 5 is approximately 30% complete. The contractor has experienced delays due to the constantly changing weather conditions last fall and early this winter. The project completion date is still scheduled for early this summer, and we are hopeful that it will be met, however, the contractor does have some time to make up.
More information can be found by visiting the City of Des Moines Engineering Department’s Projects and Capital Improvements Program Map at https://maps.dsm.city/projects/. If you have questions please contact Brad Brockman at (515)-283-4070 or at BRBrockman@dmgov.org.
Thank you for your patience, understanding and cooperation during this public improvement project.
EASTER LAKE WATERSHED PROJECT PARTNERS