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Stormwater Management in Forest Hills


Zoning ordinance overlay protects hills of the City

The tree-covered hills throughout Forest Hills neighborhoods represent the essence of the area’s natural beauty. Even more importantly, trees play an essential role in holding the ground together on the hillsides, ridgetops, and steep slopes throughout the City.

Much of the soil in Forest Hills is colluvial, which naturally washes away over time anyway. When trees on a steep slope are cut, it may further destabilize the soil because the trees’ roots were helping to hold the soil onto the hillside.

Because so much of the land in Forest Hills lies on hillsides and steep slopes, the City’s Zoning Ordinance includes passages aimed especially at preserving and protecting trees and steep slopes. It defines Hillside Protection Overlay districts and provides guidelines for development in higher elevations. Maps of the protected districts are available HERE.

The guidelines were established to protect the natural beauty and topography of the land in the face of development. As an “overlay” district, any development or land disturbance within the area must comply with the technical and development standards outlined in the Zoning Ordinance. Without guidelines, development can increase the amount of runoff after a rainstorm, which leads to greater erosion and the potential for the slope to become destabilized.

Trees play an important role in enhancing the visual quality of life and protecting property values in the City. Portions of the Zoning Ordinance stress the need for planting, maintaining, and preserving trees in an effort to limit the destruction and ensure the survival of mature trees. That’s because mature trees contribute significantly to reducing stormwater impact and reducing erosion through their extensive root systems.

If you plan to make any changes to parts of your property that lie on hillsides or steep slopes, be sure to consult with City Manager Amanda Rhinehart. She will work with you to develop a plan than minimizes the loss of trees and lessens the impact on the environment.

Pollution Solutions

This stormwater management information is provided as part of the City’s education requirement under its state permit. More tips

How to protect our watershed

The City’s hills are part of the headwaters of five different streams. Clean stormwater is essential to protecting the sources of our drinking water and maintaining our enjoyment of rivers, streams, and creeks.

Stormwater can pick up pesticides, fertilizer, oil products, pet waste, and construction debris and deposit them in its final destination, the bodies of water from which we get our drinking water.

Here’s how you can help keep our watershed clean.

Plant native trees, shrubs, and grasses

Planting native perennials, trees, and shrubs is an effective, natural way to prevent erosion, especially on sloping terrain. Long-term studies show that a hillside with a well-designed garden planted in natives has little measurable erosion.


Reduce stormwater runoff

Reducing stormwater run-off from your yard helps the environment and reduces unsightly ground erosion.


Plant more trees

The floodwaters of 2010 brought new understanding of the importance of reducing the water runoff from rainstorms. One effective way of mitigating stormwater threats is by planting trees.


Keep drainage ditches clear

Do not rake loose leaves into the City’s streets, ditches, culverts, or wherever water runs.


Use rain barrels

Rain barrels are an effective and low-cost method of managing rain running off from rooftops.


Build rain gardens

Rain gardens, also called bioretention areas or bioinfiltration cells, are shallow depressions used to improve the absorption and infiltration of stormwater runoff.


Use permeable paving

Using paving tiles that allow water to seep in between them is an excellent way to mitigate stormwater runoff from driveways and parking areas.


Prevent agricultural contamination

Lack of vegetation on stream-banks can lead to erosion. Overgrazed pastures can also contribute excessive amounts of sediment to local water-bodies.


Control construction debris

Erosion controls that aren’t maintained can cause excessive amounts of sediment and debris to be carried into the stormwater system. Construction vehicles can leak fuel, oil, and other harmful fluids that can be picked up by stormwater and deposited into local waterbodies.


Clean up pet waste

Pet waste can be a major source of bacteria and excess nutrients in local streams and waterways.

Cultural and Natural Resources richland

Restore Richland Creek Initiative


Stormwater Stormwater Factsheet

Stormwater Stormwater Ordinance