HOA responsibility maintain common areas with expansive soil

I live in a California community with expansive soils. Under the cc&r residents are responsible for wall damage due to expansive soil. Clearly there has to be some balance between the home owner and association. The original permits for the community were conditional upon proper slope maintenance. What does this requirement really mean? I assume that the association must maintain slope vegetation. Does this requirement go so far as to necessitate high transpiration vegetation? Do we have to coppice trees on the slope. Do we have to take steps tp promote drainage on the slope. Do we have to terrace existing slopes or drive piles to improve slope stability. What should we be doing to monitor the slopes.

WalterD2, I would do two things to help understand the situation:

-- Contact your City's land use department and ask how you can identify who is responsible for maintaining the slopes. Then ask your other questions above.

-- Go to the County Clerk and ask for help viewing the plat for your community. Read all the notes on the plat carefully. Typically plats record agreements (about, say, slope maintenance) such as the one you describe. Plats are on publi record precisely so everyone is, as much as possible, on the same page when it comes to who is responsible for what. County Clerk's usually have several staff who have assisting the public as one of their duties.

-- I have seen developers wangle their way to City approval to build on very steep slopes. The impermeable surface (roads, building foundations et cetera) laid typically causes or increases flooding in downhill neighborhoods and erodes the mountainside unless extraordinary measures are taken. Last time I saw this, the covenants and plat requirements for the development were insanely long and complicated. Many of the downhill neighbors did not for a minute think a HOA could keep up with all the civil engineering equivalent of duct tape and glue needed quarterly and annually to keep the mountainside from eroding and causing massive flooding downhill. I have seen Cities end up paying a fortune to correct drainage and erosion problems, due to hastily approving such developments. I know realtors who refuse to sell homes in such neighborhoods, because of soil instability causing a high risk of home foundation damage.