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The Rainbow River Restoration Project

How to save the river and prevent future poisonings

According to the Southwest Florida Water Management District’s (SWFWMD) website “the Rainbow Springs springshed, which contributes groundwater to Rainbow Springs, is approximately 735 square miles of mostly agricultural lands, forested uplands and growing urban areas. This springshed covers portions of Alachua, Levy and Marion counties.” Additionally, Rainbow River suffers from one of the highest nitrate levels for springs in this region. This leads to decreased water-quality, increased algae and invasive species, and decrease in the health of the whole ecosystem including the animals and insects that rely on the water.

Due to the increase in invasive species strangling the waterway, regular herbicides have been applied to the river. However, poisoning Hydrilla has had minimal success and harmed other parts of the ecosystem. The herbicides used on the Rainbow River include Diaquat, Fluridone and Endotholl which leaves behind plastic polymer jellies. The dead plants then fall to the bottom where they are left to decompose causing a thick muck to build up and smother the plants. Without plants producing oxygen, Lyngbya, a filamentous algae, moves in further blanketing the area in thick mats of smelly and potentially toxic algae.

This restoration effort will follow the Kings Bay Restoration Project model to remove the muck and replant native submerged aquatic vegetation (SAV). See the steps below to learn how we can accomplish this monumental task and ensure the river remains healthy for generations to come.

Read previous scientific studies done investigating the Rainbow River
Photo by Sea & Shoreline

Divers carefully hand vacuum detrital material and muck off the river bottom. This allows them to ensure only the bad stuff is taken and the good sandy bottom is left intact so plants can grow and thrive.

Divers will periodically monitor the restoration areas to ensure the plants have the best chance at survival. Any muck or algae that washes in will be removed to prevent it from smothering the plants. This will be done for three years.

Photo by Sea & Shoreline

This muck on the bottom can be several inches thick to several feet thick is removed which prepares the bottom for replanting. Plants will be cultivated in Sea & Shorelines inland aquatic nursery which is the largest aquatic nursery in the world! This means plants are not just taken from one waterbody and planted in another through what is called wild harvest. A variety of methods will be used to install these native plants including plants in biodegradable peat pots and small little pellets containing a single plant. The method chosen will be the one that is best for that water depth and river condition.

Photo by Sea & Shoreline
Photo by Sea & Shoreline


See how other restoration projects are making a difference:

Check out Sea & Shoreline’s Report from Kings Bay – this is what we will accomplish in the Rainbow River!

Polymer jelly from poison
Example of Lyngbya mats
Dense stands of Hydrilla

Frequently Asked Questions

No, vacuuming takes place under water. The muck is piped onto land where it will then be sifted and clean water will be extracted. The bulk of the muck ends up in a huge bag that has tiny pores. Clean water seeps out and the muck stays in the bag. When the bag is full it is split open and the muck hauled away to serve as a natural fertilizer for inland pastures. If you are on the river boating or live near by you won’t notice a difference in smell.

Nope, a diver will be in the water with a small 3 inch suction hose to carefully remove the muck. Watch this short clip of Sea & Shoreline divers to see how they do it. As you can see, the water column doesn’t even get that cloudy! Divers are specially trained to ensure the good sandy bottom stays put and the muck is carefully removed. Once the muck off the bottom is gone there are some legacy nutrients in the sediment that now come to the surface. Sometimes residents will notice a few brief algal blooms as the algae feeds off of those nutrients. Once consumed, the blooms go away and won’t be back. It is just a sign that the river is resetting back to a healthy state.

Absolutely not! Small areas will be sectioned off so divers can work safely but boating corridors will be left open so the river can be enjoyed by all. If there are little tributaries or coves that need to be cleaned they may be blocked briefly if it is not wide enough to accommodate divers and boats. If areas around boat docks and structures need to be cleaned, owners will be notified in advance so that boats can be removed if needed ahead of work. The long term benefit will certainly outweigh a minor inconvenience of having to boat around a small barge.

The Southwest Florida Water Management District (SWFWMD) shows that the lower river is the most impaired as you can see in this infographic they have. SWFWMD also notes that Lyngbya is most prevalent in the middle and lower river. By addressing the worst areas first we can speed up the whole river’s recovery.

Previous studies such as the Springs Institute water quality survey are not applicable to use as the benthic survey needed for a US Army Corps of Engineers and FL DEP permit.

Here are links to the two full documents:
1) Springs Institute Rainbow River Monitoring Reports: https://floridaspringsinstitute.org/springswatch-rainbow-river/
2) Sea & Shoreline’s permit application to FLDEP for Save Crystal River: https://prodenv.dep.state.fl.us/DepNexus/public/electronic-documents/ERP_322556/gis-facility!search
To find the current permit for Phase 2-4 click to the second page and it is dated12/20/2018

Key differences between the two studies:

  • The Springs Institute is monitoring water quality for the most part. They do a little sampling of SAV coverage but not enough to be applicable to an engineering survey

While this is great to assess the health of the river and it’s ecosystem it isn’t a fine enough resolution needed for these complex permits.

  • The DEP permit and the Army Corps permit that are needed have to include technical specifications and drawings at a much finer resolution. They have to conduct transects across each area to be cleaned and calculate the amount of muck to be removed. They have to have detailed drawings of how the dewatering site will be set up, where all the pipelines will be run in the water, and other technical engineering requirements including how many plants they think will be planted.

Think of these permits as needing technical blue prints to carry out each aspect of the job. It goes way beyond just assessing water quality in a few locations along the river.

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