Planner Speak: What exactly is a slope?

If you’re an avid skier or snowboarder, you’re probably looking forward to winter when you can hit the slopes and make fresh tracks through the powder. If a planner told you there are steep slopes in Hamilton County, you might look at him in disbelief. We may have gotten a lot of snow last year, but not enough that someone would consider building a ski resort. What exactly do planners mean when they talk about slopes?

Slope (n.) is the steepness of an area of land, or how quickly the land goes up over a certain distance. You can measure the slope of land the same way you measure the slope of a line in algebra class: by dividing the “rise” by the “run”.


Let’s say that you have a piece of land that is 100 feet long, and it rises 20 feet in elevation from one side to the other. The “rise” is 20 feet and the “run” is 100 feet. If you divided 20 by 100, then .2 would be the slope. Usually, planners talk about slope as a percentage. To covert .2 to a percentage, you would multiply by 100 giving you a slope of  20%.


Typically, a slope of 15 – 25% is considered steep, and a slope over 25% is considered very steep. In Hamilton County, over 30% of our land area has a slope of 15% or greater as you can see in the map below.


Our mountains, ridges, and slopes are key features of our natural, scenic beauty. They can offer a beautiful backdrop, especially when the leaves change color in the fall, or a magnificent view of the valley below. The hilly land is one of the defining characteristics of our local identity. It also makes many of the activities that both residents and tourists enjoy possible including hiking, trail running, hang gliding, mountain biking, and rock climbing.

Signal Mountain

Not only do slopes bring scenic beauty and recreational opportunities to our area, but they also play an important role in the health of our natural environment. Slopes that have not been disturbed provide a home for wildlife and improve water quality by slowing or reducing rainwater runoff. Disturbing a slope could involve removing plants or soil or building something on the slope. Disturbing slopes increases the risk of slope failure or instability, meaning that rocks and soil could start to erode, slide, or collapse. For these reasons, it is important to protect steep slopes: for their scenic beauty, for their recreation opportunities, for their role in the health of the natural environment, and to avoid costly repairs to buildings and the infrastructure, such as roads, that would be needed to provide services to buildings on steep slopes.

Where’s Tim Now?

Last week Tim was on the South Chickamauga Creek Greenway. The greenway is a path for walking, running, biking, and skating that runs next to the South Chickamauga Creek. Here is a map of the completed sections of the greenway. The Trust for Public Land is currently working on connecting the missing segments to complete the entire 14-mile greenway and connect it to the Tennessee Riverwalk. For a preview, check out this video tour of the newest section of the greenway.

S Chick Bikers-JT_answer

Planner Speak: What on earth is a streetscape?

You have probably brought back photos of stunning landscapes from a vacation, but what about a streetscape? If someone asked you to take a picture of a streetscape, where on earth would you point your camera?

Streetscape (n.) is the appearance of the street, including the entire area between the buildings on either side of a street. Elements of the streetscape include:

  • the front sides of the buildings;
  • landscaping, such as trees, grass, flowers, and bushes;
  • stormwater management features;
  • sidewalks;
  • signs;
  • street furniture, such as benches, bike racks, trash cans, and water fountains;
  • street lights;
  • features of the road including crosswalks, bike lanes, cycle tracks, parking spaces, travel lanes for cars, dedicated lanes for buses, and medians; and
  • street paving, such as asphalt, concrete, brick, or stone.

17th Street     Flick-user-la-citta-vita-CC-BY-SA-2

Paul-Krueger-CC-BY-2.0-v2     Baker-Co-Tourism-CC-BY-ND-2.0

The streetscape can make a big difference as to whether or not people enjoy and feel comfortable traveling down a street, regardless of if they are walking, biking, driving, or riding transit. Trees and awnings can provide shade or shelter from the rain for people who are walking.  A wide sidewalk, without obstacles in your path, makes it easier to walk side by side and chat with a friend, push a stroller, or get around in a wheelchair. A row of landscaping between cars and a bike lane, also known as a protected bike lane, can make it more comfortable to bicycle on a street with lots of traffic. Walking next to buildings with lots of windows with interesting things to look at is more enjoyable than walking next to a solid, blank wall or a large parking lot that separates the buildings from the sidewalk. Lighting that is directed towards the sidewalk can make it feel safer to walk at night.

The streetscape can also make a big difference as to whether or not a street is a comfortable and attractive place to stop and stay for awhile. Outdoor seating in front of a restaurant allows people to enjoy a meal and watch people passing by. Covered bus shelters can protect you from the elements while you wait for the bus. Bike racks in front of stores give you a place to lock up your bike so you can feel confident that it will be there when you return from running your errands.

If you’d like to try your hand at designing a streetscape, check out Streetmix. We’d love to see what you come up with! Share your designs with us on twitter by tagging @RPAchat or on facebook by tagging @chcrpa.