We have constructed a 60 ac. reservoir with 14-16 high levees 36-40' wide. We are having issues with getting grass to grow and would like some help/suggestions for plants and or trees to stabilize the banks to curb erosion from wind-wave action. Any thoughts/resources? Thanks.
Welcome to PB. Avoid trees on the dam. Their roots will weaken it. Bermuda is the go to grass for dams. Although this is not really the time of year to plant seeds, I think I would have to try. 60 acres of water takes a lot of dam and without plant cover, you can probably expect a lot of erosion. There might be other types of grass that have a chance at this time of year. Winter rye comes to mind in the Fall.
Bottom line is that I would try Bermuda now and rye in the Fall.
I am told that cypress has a shallow root system.
According to Google "Cypress is valued for its extensive root system, it is widely used for soil erosion control. The well-defined taproot accompanies fast-growing lateral roots, but surface roots are not a problem. The tree grows 70 to 90 feet in height and matures to a 30- to 40-foot spread in USDA zones 7 through 9."
P.S. This is a rectangle lake with four "walls/dams".
As the water is 10'-16' deep, what about some shoreline grasses?
Are you able to irrigate the grasses? This time of year that's what is needed to encourage grass growth.
There may be less damaging tree for a dam, but the ultimate problem is that the roots grow through the dam, the tree eventually dies, the roots rot, and then you have a path for water to follow that leads to a leak.
The best way to sow grass is with a machine that mixes water and straw and wet seed. Hydro seeding I think they call it. That or erosion mats but you are talking about a lot of area.
If the reservoir is full you might consider some rock lining in strategic locations where wave action will be the worst.
bank reosion and rock lining
We planted cattails along the edge to stop the wave erosion. Worked well, just be careful - plant the wrong thing and you may spend the rest of your life trying to kill it after it overtakes your impoundment.
14-16 ft tall and only 40 ft wide? With a 5’ top width, that leaves you around a 1:1 slope. That is steep and sounds like what could be your problem. Most soils are going to sluff (slide downhill) when saturated on a 1:1.