Grass waterways are necessary to prevent erosion from surface runoff and reduce gully erosion. The vegetation slows down the water especially on low lying areas of the field, in between hills etc., where water tends to concentrate. Weather conditions have been hard on waterways the past few years.  From drought conditions, that prevented successful establishment of grasses in the waterways, to torrential rains, many waterways are in need of help.  As a result, there have been questions on how to repair the damage or reestablish the grasses in thin spots.

There are several strategies for waterway repair, depending on the severity of water erosion and the calendar date of re-seeding. It is always best to fix damage to waterways as soon as possible, before damage gets worse and becomes more costly to repair. This spring is also a good time to re-evaluate the capacity of the waterway to carry water runoff. The grower or landowner may wish to increase the width of the waterway while making other repairs. In most cases it will be difficult to re-establish grass in a functioning waterway because of periodic flowing water. Areas where you have bare spots from erosion may require additional soil before re-seeding. It might work better to slightly over fill these areas to allow for settling, and to divert water away from the new seeding until the grass becomes established. 

Another question that is frequently asked is “What grass species is best to use for reseeding?” Reseeding with a perennial grass is preferred over reseeding with legumes. The primary goal is to establish a healthy, vigorous sod to hold the soil in place during high water flow. Including some annuals such as annual ryegrass, oats or wheat will help to ensure that good cover is quickly re-established during the reseeding project. It may also be beneficial to consider grasses that have higher drought tolerance, like tall fescue and smooth bromegrass, to ensure adequate vegetative growth during periods of hot and dry conditions.  These grasses also work well when thunderstorms brew up quickly and dump heavy rainfall. Finally, it may also be necessary to consider a grass mixture that contains a ratio of grass varieties that can compete and establish a uniform sod. 

A good mixture of grass varieties, for a fairly wide geography, includes tall fescue, smooth bromegrass, and annual ryegrass in a 70%/20%/10% ratio. This mixture is found in the FS 64 Waterway Mix. Ideally this mixture should be planted at a seeding rate of 20-30 pounds per acre, and at a planting depth of ¼ to ½ inches. The fescue and bromegrass will both provide good drought tolerance during hot, dry summer conditions, as well as very good sod forming root growth to hold the soil in place. Additionally, the annual ryegrass in FS 64 will help to provide good soil cover quickly as the fescue and brome grass develop. The tall fescue variety used in FS 64 is a low-endophyte variety.  When combined with smooth bromegrass, this can make a good grass hay.

For more information on grass species selection for waterways contact your local FS Crop Specialist. You can also find more information on this PDF.