The following are requirements for selecting a street tree planting site:
- Site will require a terrace width of 4 (four) feet or greater.
- Public safety must not be compromised when planting near intersections. Tree planting at intersections require sight triangles (refer to diagram) for motorist/bicycle safety. Sight triangles are defined by MGO 27.05 (2) (bb) Vision Clearance at Intersection Corners.
- Trees planted along the terrace to the right or left as you approach an intersection must not impede the vision of pedestrians, bicyclists, drivers of motor vehicles or interfere with signs. When approaching an intersection on a two-way street with a 25 (twenty-five) MPH speed limit, trees planted along the terrace to the driver’s right are planted a minimum of 50 (fifty) feet back from the right-hand corner (Point A). This distance is increased proportionately as the speed limit increases at a rate of 5 (five) additional feet for each 5 (five) MPH increment in speed.
- Trees are planted a minimum of 35 (thirty-five) feet back from the left-hand corner (Point B). This distance is not affected by increased speed limits on two-way streets.
- Greater line-of-sight distances will have to be provided at railroad crossings (Wisconsin State Statute).
- Clear sight lines for stop signs, signals, overhead pedestrian crossing lights.
-
The greater the mature height of tree will require greater terrace width for a sustainable tree.
-
At least 3 (three) feet of soil depth is required.
-
Species diversity – at minimum 3 (three) species per block.
-
Where there are overhead high voltage lines (MGE/Alliant/ATC) trees should not have a mature height greater than 25 (twenty-five) feet. Right Tree, right place.
-
Existing private trees (species type and proximity to potential street tree planting site) needs to be considered to optimize tree health and accommodate future growth of tree for both the city and private tree.
-
Maintenance consideration of adjacent structures (buildings, permanent awnings, bus shelters, etc.).
-
The style of light is considered. Street lights need to cast a light for public safety reasons and not be impeded by street tree branches as the tree reaches mature height. Trees should be planted at minimum of 20 (twenty) feet from the light.
-
Tree shall be planted at least 2 (two) feet from underground utilities (sewer lateral, water lateral, gas lateral, communications, electrical, etc.)
-
For public safety reasons trees should be at least 10 (ten) feet from any traffic control signs or placed behind the traffic sign (i.e. school crossing, no parking, speed limit).
-
Trees should be placed at least 6 (six) feet from driveways.
-
Mature height of the tree will determine minimum spacing between street trees:
- 25 feet mature height = minimum spacing of 30 feet
-
> 25 feet mature height = 40 feet minimum spacing
-
Fire Department requires aerial apparatus access to newly built buildings taller than 30 (thirty) feet per fire codes. 50% of the designated Fire Aerial Apparatus Zone needs to be unobstructed by tree canopy.
-
Other hardscape items located in the right of way such as utility poles, mail boxes, fire hydrants require trees be planted at a minimum of 10 (ten) feet.
-
Disease and insect threats (Dutch Elm disease, emerald ash borer, Asian Longhorned beetle, etc.).
-
Overall species make up of the street tree inventory.Current species make up on the block.
-
View restrictions per development agreement (example: Blackhawk subdivision).
-
Type of care and environment the tree needs to grow to mature height (durability, road salt, soil type, watering, presence of heavy metals, drainage, and shade tolerance).
-
- Industrial area
-
Downtown
-
Grate and cut out sites
-
Rain gardens