Dredge Report #9 – The Dirt on The Dirt

The Dirt on The Dirt

In the week-plus since the last DR many changes have happened, as evidenced by the machinery in the lake bed, the mounds of earth, the trees that have been cut and stacked, and the lightning strike that delayed this report and rendered it photo-less.

There have been several inquiries about the dirt that’s piling up next to the changing stream bank: when and how it can be collected for use in yards and gardens; how it’s being managed to protect the stream from sediment as construction continues.

As of this date Phil and Josh Maner (the on-site project manager) are considering trucking the silt removed from the lake bed to the PW building where it can dry and be made available to residents.

As for the erosion and sediment controls along the stream bank construction, there is nothing at this time to prevent some dirt from washing into the stream should there be a rain event.However,in the State of Georgia no in-stream erosion control is permissible (including silt fence).In fact, the designer proposed certain in-stream controls but upon review, the State required the designer to remove those controls.

The basics are not being ignored. On a daily basis the contractor provides such erosion control as is necessary and reasonable and in keeping with the State issued permit. For example, jute matting is being placed on the slopes as the work progresses and PAM mulch will be applied to this and to the bench at the waterside. In addition, the top of the new berm is currently sloped such that rain that falls on the top of the berm will flow into the lake, not the stream, capturing all silt in the now dry lake bed (which, during the course of the work, cannot flow into the stream and will ultimately be removed as work progresses there). Erosion controls are adjusted at the end of each work day to meet the intent and letter of the permit.

A significant amount of silt was already washing into the stream during every rain event- note the raw banks with no vegetation along the northside of the stream. This project will alleviate that problem.

The city and the State regulators understand that a project of this type will necessarily create some concerns and even problems during the course of the work but that the end result will be to create a habitat and bank structure that will keep future erosion to a minimum.

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