Rainwater Mitigation Pond – Lake Minnetonka Minnesota

Rainwater mitigation on a Huge scale

This beautiful lakefront project was another great challenge on what to do with the water.  With less than two inches of slope from the front of the lot to the lake and no drainage system or gutters we needed to find a creative way of draining the whole front of the house gutters and driveway.  The answer came in the form of a large 5000+ gallon retention pond with over 100 feet of stream that empties in the lake.  An almost 6 foot tall “bubbling rock” provides water movement at any water level while discouraging mosquitoes and stagnation.


Private Residence, Tonka Bay – Lake Minnetonka Minnesota

Native plants for habitat and diversity

With around 130 native plants brought in to line the stream and pond the goal was to make a water feature that looked like it had always been there.  With a wide range of plants from aquatic to riparian to terrestrial we tried to provide a broad representation of flowers and species to enhance and increase the local pollinator species. In addition to all of the beauty and habitat, these plants will all provide some degree of filtration for the water that was designed to ebb and flow through this entire feature.

Aquascape / Environment

A native Minnesota ecosystem with plants chosen specifically for filling as many different roles in the ecology as possible.  A great deal of care was taken to ensure that the stream and pond became an extension of the shoreline.  Where lake water and rainwater drainage were able to merge and recycle repeatedly enabling the plants to remove as much (N)itrogen, (P)hosphorus, and Potassium(K) as possible along with other nutrients.

System Function

The real trick to most aquatic systems is to maintain the highest oxygen levels possible. Retention ponds and swales generally become anaerobic due to the amount of sediment they collect.  In designing this system I chose to do a series of small ponds in the stream to allow wave action and water volume to push and pull water through the stream.  Since water always seeks to level, a wave coming into the first pond will push water down and back into the rest of the stream and keep the water moving.  No liner and a substantial amount of rock hold everything firmly in place while allowing the water to percolate into the soil and water table and move freely as water would in the natural water cycle.


The huge volume of rock and materials required working with another landscape company to provide the client with the highest quality finished product.  It only took about 5 days to lay in the entire pond and stream and do all the planting. After a few years the project has really filled in and provides a functional and beautiful focal point for this property.

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