Question
Hi,
-Interesting that you want a challenge.  Here's one I hope, but it may not strictly be a pond question, but it sure is water.  And I am looking for a decorative as well as utilitarian solution to this.  But beyond the initial set-up, it's not something I want to constantly tend.  
-Here's the layout.  To the west of the cement driveway, there is about 12 feet of grassy area to the fence.  From the front of the property to the front corner of the house is about 30 feet--so this is a 12X30 rectangle.  And it slopes just so gently toward the rear, not more than s few inches.  Now beside the house, it starts to slope more, and by the time you're at the rear corner, it's something like 4 feet lower.  Right now there's both grass, concrete steps about halfway back and a cement path along this side of the house.  Imagine again the 12 feet by about 40 feet until you reach the rear corner of the house.  So when it rains, the water drains from the front driveway and the 12x30 patch down the side of the house, gushing over the steps and finally spreading out into the back yard.
-I'd like to pretty much eliminate the grass and weeds and just make it like a river bed maybe with a waterfall where the steps are, where it suddenly drops off a few feet.  I'd like to start at the front of the property with the project--eliminating the grass/weeds on the 12x30 rectangle mentioned above.  
-I was thinking of covering the whole area--from front of the property to back corner of house with that thick pond liner and hauling in rock after first digging/contouring the ground underneath so that the water would tend to be channelled in the center rather than against the house.  Your thoughts?  Also, how to deal with that sudden drop off of the steps--the waterfall idea.  How to construct that so you don't see the pond liner?
-Anyway, is this too big of a project for you to deal with.  It probably needs someone to draw out things, and maybe this site is not the place for that.  
Carl  

Answer
At one of the highest points is where you need to put the waterfall and trench it to the lowest where the pond will be, line the trench with liner material as well as the pond.You could anchor the sides of the pond with rocks or patio stones. You could cover the liner with a layer of pea gravel but it is likely to wash down into the pond. You might try to put large rocks along the trench in different spots to diffuse the water and give a soothing water sound.
Hiding the liner is completely is difficult. the other problem is the pond will need an overflow trench with a screen to prevent any fish or plant from being washed away.
It is an ambitious task but it can be done with alot of thought and hard work. Wish I could be of more help but is difficult without seeing the situation

            KEEP PONDIN
               Leigh