Understanding Streams

Rivers, streams, and even ditches are complex natural systems that not only drain water off of the land toward the oceans, but provide innumerable other functions, including the transport of sediment and debris, flood control, habitat, and recreation.

where do rain drops go infographicAs with any part of the natural environment, the details of the relationships between parts of these systems are highly complex, which makes it difficult but necessary to view these systems completely and comprehensively.  Working to understand these systems is critical to our efforts to protect, maintain, and restore our local water resources. To paraphrase Newton’s third law of motion – every action causes a reaction – and this is especially true for these complex natural systems. Here we will dive further into the world of rivers and streams and discuss our Program’s efforts to protect, maintain, and restore our local rivers, streams, and ditches.

There are several streams in Porter County, some of which require restoration. Why would a stream require restoration? Let's first talk about storm water runoff. When it rains, storm water lands on a variety of land types such as grass, exposed soil, roof tops, roads, etc. that allow a certain amount of storm water to infiltrate. For example, when it rains on a grassy area (pervious), the water will soak into the soil beneath. When it rains on a sidewalk segment (impervious), the water runs off of the surface since it cannot soak into the concrete and into the nearby grass or perhaps a storm sewer inlet. The amount of storm water runoff will increase with an increase of impervious area - area where water cannot infiltrate. 

An important process to understand is how much time it takes the water to flow from its starting point, for example your yard, to the end point in the stream, the Little Cal River. This is known as the time of concentration.  Usually for watersheds, the time of concentration is used in combination with other storm water calculations to predict how much water will arrive downstream within a certain time frame. With high amount of impervious area/low infiltration creating more storm water runoff, the runoff flows quickly and directly to the storm sewer system in residential and commercial areas or ditches and streams in the agricultural areas. The runoff can reach a high velocity, which over time can deteriorate pipe outfalls and stream banks. Most of the land in Porter County has been developed into either agricultural or residential use.  These land types do not allow as much infiltration as undeveloped land. The result is many streams requiring restoration projects. 

Crooked Creek is a good example of a high volume stream with clear signs of stream bank erosion. This video was taken with the Department drone, which can fly over the creek and inspect the stream's condition. As video plays, it is clear that certain banks are no longer vegetated and are slowly eroding and collapsing under the force of water flow. 

Check out the side links for the Crooked Creek Restoration project information.