Wow - from way general to totally specific - nice job, you have your scope of work almost ready to contact potential bidders about giving a bid - just need to double check each item hads quantities attached to it, plus a plan with depths (or specify tie-in elevations to existing pipe and required drain/pipe slopes - say 1% or more). Search the List (in green banner bar) for Earthwork and Excavation contractors in your area with good reviews and ratings.
here is a very rough idea of costs - obviously you need bids to tie it down, this should just give you a ballpark to compare to - assuming all this work is done at the same time.
1) & 2) - Tree and rock maybe $100 - more like $200 if you want the stump totally rooted out rather than just the stump and root crown taken out.
3) Walk removal and disposal probably about $100-200 - maybe half if these are 3-4 inch individual concrete squares or rectangles that can be skidded to the side, the excavation and ground sloping done, then slid back into place with a backhoe or bobcat or by wood skids and prybar, eliminating the hauling and disposal cost.
4) Excavation and disposal of soil probably about $20-30/CY, because you are talking a small quantity. Cheaper if you have an on-site area it can be spread out onsite for disposal, or stockpiled in yard as a future project dirt pile, if that is suitable.
5) You don't say what the existing drain is - underground drain for downspouts maybe ? For shallow burial, probably about $5/LF or so. Why square - round is cheaper and far stronger for given material thickness.
6) Fence R&R probably about $150-200, depending on depth of posts and whether concreted in or not.
7) vegetation removal - not knowing how much, $100-200
8) Garden wall around $10-12/SF assuming excavated material from yard is suitable for the general backfill - remember should go 4-12 inches below grade for stability (4" for this wall, more like 6-12 for higher front wall)
Front/side yard:
1) Move large boulder - $50-100
2) vegetation removal and relocate 3 shrubs - $150-300 (not knowing how much vegetation orhow big shrubs are)
3) excavation at $20-30/CY again as above
4) sprinkler system relocate/repair - $75-150
5) garden wall around $12-15/SF as above including concrete footer needed for this height wall
6) area drain laterals about $5-10/LF, assuming not over 3 feet deep
7) slab drainage - I don't know where the quick lime idea came from, but this is a no-go - it will remove a small amount of water (maybe 5-20 gallons) from the soil one-time - it has no long term function as it will quickly become saturated. You are actually likely to have 5 wet circles in your concrete slab from this forever, as the lime will act as a soggy sponge, retaining water that would otherwise wick away. If you have or expect a basement slab moisture problem, then you need a sump pump with sump installed, and possibly (depending on how free-draining the base material under your slab is to carry waer to the sump pump) lateral drains cut in below the perimeter of the slab. Can run from $800-1500 range for a pump and pit depending on capacity and wiring situation, plus $500-1000 for an emergency battery-powered backup if desired. $1000-2500 range typically if lateral drains around the perimeter of the slab are necessary. Cheaper but sloppier and moisture-causing solution is small trenches or above-slab channels to carry the water to sump pump. These laterals are commonly held off on till you see if the sump pump can handle the issue itself, ASSUMING you have unfinished basement so a bit of seepage aroundbthe slab does no more damage than needing a mopping up. Personally, unless you have a continual seepage of water into basement or it is finished so leakage is critical, I would leave sump pump and drains for later - to see if your surface drainage changes eliminates the basement dampness problem, which it commonly does unless your water table rises to the basement slab level. Also, having a sump pump implies water issues and tolls against any future buyer finishing an unfinished basement, so it detracts from resale value if you have one.
Note these are off-the-cuff type numbers, NOT any sort of deliberate estimate - but I felt it was better to give you a ballpark than to just say go get estimates. Except for the floor drains, this sounds like a good job for a small 1-3 man excavation and hauling company, but make sure they have experience in putting in drain pipe and block walls and have good references in that area.
Note- if you are inclined to do it yourself work and have the time, most of this is good homeowner home improvement project material. You could have a contractor with a bobcat or small tractor with small backhoe come and pull the fence posts out (you could remove the above-ground apart easily), trench for the pipes, maybe move the rocks and sidewalk (though you could do that yourself with a few scraps of wood as skids and a 5 foot prybar assuming the walk is in piece, not continuously reinforced, and to do the bulk excavation and hauling for you, leaving the vegetation clearing, pipe work, trench backfilling, final slope dressing, block wall building, transplanting, etc to you - could cut your cost about 1/3-1/2. Basement slab drainage I consider a separate issue which would not cost significantly different if done as part of this job, or later if drainage channels or slab french drains are deemed necessary.
For the excavation - remember to get utility locates - I recommend once for bidding so they know where utilities are, then require the bidder to get relocates just before excavation starts. Gas, telephone, cable TV are commonly less than a foot down - water and sewer usually 3 feet or more but don't count on it. Also worry about septic system is you have that, and any power or water lines to/from well if you have a well. Plus of course your sprinkler system if in the way of proposed excavation.
Good Luck with your project
