What are Riparian Areas and Why are they Important?-The scientific community, including TUC biologists and staff, often use terms, such as riparian, that most people aren’t aware of or perhaps don’t understand. Riparian areas are defined as the transitional area between an upland dry area and a water body such as a stream or lake, commonly referred to by some as the shoreline region.

The key distinguishing characteristic of a riparian area is its hydrology or how both surface and groundwater are delivered to, routed through and absorbed by the area. Riparian areas are further identified by the occurrence of various water-tolerant types of plants and trees such as cottonwoods, willows and sedges. The presence of these species usually depends on the size and location of the stream or water body. For example, larger streams may have a combination of these species, while smaller streams may only have sedges growing within their riparian area.

Riparian areas are rich in biodiversity and much more productive than their adjacent upland areas. The un-compacted soil beneath riparian areas is honeycombed with cavities and passageways created by decaying roots, burrowing animals and fungi, making it porous and absorbent. Riparian areas serve critical ecosystem functions important in maintaining the balance and water quality of a river, stream or lake including;

Vegetation filters out sediment from entering the stream. Their roots also bind the soil together to reduce erosion,

Their roots also bind the soil together to reduce erosion, The surrounding trees and plants provide important food sources for aquatic insects and shelter for fish.

The shoreline vegetation offers shade and wind protection that helps regulate water temperature.

Provides critical habitat for insects, amphibians, and other wildlife.

During high flows, such as spring run-off, riparian areas store water, releasing it to the stream during low flow periods.

Riparian areas absorb and dissipate water energy during floods and other high water situations.

Water quality is also enhanced by other physical, chemical and biological processes, which are driven by the local ground and surface water. These processes, which occur in the soils and vegetation, assist in removing or lessening the impact of excessive nutrients and harmful pesticides entering the water.

During a flood or other high water occurrence damage to the riparian or shoreline area may occur resulting in the removal of vegetation or sections of the bank. After the event, the riparian area begins to heal naturally. Over time vegetation, such as willow shoots, sprout up through deposited gravels and mud reinforcing the bank once again. Human intervention to repair the damaged shores and banks of riparian areas frequently involves “quick fix” solutions by replacing the lost vegetation with rip rap. Rip rap, loose stones and rocks used to form a foundation for a shoreline or breakwater structure, alters the riparian area, preventing the natural re-growth of vegetation. Bank armoring using rip rap may also impede the flow of groundwater into the stream and deflects water energy to less protected areas resulting in addition damage. This practice is particularly harmful to smaller streams where groundwater is a major source of stream flow that maintains water levels and adequate temperature to support aquatic life.

Bio-engineering techniques, which may be more labor-intensive but often take significantly less time to install and are less costly allow natural growth to develop and restore disturbed banks and shores. Wattle fencing and live staking using willows and poplars within riparian areas preserve the connection between the upland areas, stream channels and the shore. Wattle fencing consists of short retaining walls using live vegetation such as willows and poplars and can be used to stabilize slopes of disturbed riparian areas. These fences, installed in terraces down the slope, preserve the connection between the upland area and the river, stream or lake.

TUC has partnered with other organizations on several projects such as Mallard Point where bioengineering techniques were successfully used to restore and protect damaged riparian areas.

What can you do to Protect Riparian Areas?

Everyone has the responsibility of protecting riparian areas. Some of the actions you can take include: