Sanjay : One of the 1st people that you must talk to is a
local geologist who can tell you at what angles the sides of Your future pond my rest at !
As Your ponds soils become waterlogged they will have a tendency to 'slump' Over time your Bowl shaped Pond will become a Shallow dinner plate with
swampy waterlogged margins !
A very important issue for ANY plant growth on the bottom of your ponds is turbidity and amount of algae micro-plants, the clearer the water, the
deeper light can penetrate to towards the bottom ! Your Choice in fish species will have a lot to do with how clear your water is !
Also the deeper your pond is the harder it will be to seal the pond to prevent water loss and possible dam collapse in indeed your plans call for a dam structure.
You may be able to terrace the
land and stabilize you soils perhaps with retaining walls of 'Rip-Rap' with or without Gabions ! This would be a first start ,
allowing you to have a shallow pond that you could then use Animals* and Animal 'Gley' to seal the bottom moving slowly towards your goal !
Bamboo has a reputation for being good for planting on the margins of ponds lakes ! Good Luck ! Big AL
* Ducks , pigs, water buffalo are commonly mentioned for this process - See Link below !
http://www.geofflawton.com/fe/78976-fixing-a-leaky-pond-with-ducks
Finally in the following link look at the 3rd picture down, a combination of gab ions and rip rap, with gabions used for a base even taller and steeper retaining
walls are Generally possible ! A.L
http://elementsunearthed.com/2010/06/09/the-legacy-of-the-tintic-mining-district/