If you have already laid the patio, planted the beds, and now watch a puddle sit for two days after rain, the fix is not another load of mulch. It is finding out where the water is trying to go and who is qualified to tell you. Most of that answer comes from four or five trades whose work sits directly against your decision, and knowing which one to call saves you the cost of guessing twice.
Decoration is reversible. Grading, pipe, and compaction are not, or at least not cheaply. What follows is the order worth running, and the person who owns each answer.
1. Where the roof water lands, and what the gutter crew can tell you in ten minutes
Start at the top, because roof runoff is the single largest volume moving across a small property and it is the cheapest thing to redirect. A gutter installer can walk the perimeter and tell you whether the downspouts discharge onto the surface, into a buried line, or into nothing at all. They can also tell you whether the buried line is still connected, which is a surprisingly common failure: the elbow separates underground, and every storm dumps water at the foundation while the visible parts look fine.
Ask them specifically where each downspout terminates and whether the discharge point is downhill of the area you are decorating. If a spout empties uphill of a new planting bed, that bed is a catch basin with flowers in it. Extensions and a reconnected line are a few hundred dollars of work that changes the behavior of the whole yard.
2. Whether the ground actually falls away, and why the hardscape installer measures rather than eyeballs
The rule most crews work to is a fall away from the house across the first several feet, and then a continuous path to somewhere the water is allowed to go. A hardscape or masonry contractor will shoot this with a laser level or a transit, not by looking at it. Eyeballing grade on a lawn is close to impossible, because turf hides an inch and a half of settlement easily.
If your patio was set level for comfort and the surrounding soil has since settled, you have a shallow bowl. The recovery is usually less dramatic than people fear: lifting and resetting a band of pavers along one edge, or cutting a drain channel at the low side and tying it into a discharge line. Ask for the measured numbers before and after, in writing. A contractor who gives you the fall in inches over a stated distance is a contractor who intends to hit it.
3. What the soil does with water, which is the excavator's department
Two yards on the same street can behave completely differently because one sits on sand and the other on clay. An excavation contractor or a site work outfit can dig a test hole, fill it, and time how fast it drains. That single number decides whether a dry well or an infiltration bed will work on your property or whether it will simply become a bathtub with gravel in it.
This is also the point where the scope of the project becomes honest. On tight clay, the answer is usually conveyance: move the water somewhere else through pipe. On sand, you can often absorb it on site. Spending on the wrong one of those two strategies is the most expensive drainage mistake a household makes, and a two-hour percolation test is what prevents it.
4. Where the water is legally allowed to end up, and who at the municipality knows
Stormwater discharge is regulated, and the Environmental Protection Agency oversees the national framework that local programs operate under. In practice, what matters to you is narrower: whether your town allows a private drain line to tie into the street system, whether you may discharge to the curb, and whether you are permitted to send water toward a neighbor's lot. The person who knows is in your local building or public works office, and the call is free.
Get the answer before the trench is open. A licensed drainage contractor will usually make this call as a matter of routine, but it is worth confirming they did. A line that discharges where the ordinance does not allow is a line you may be told to dig up.
5. What the trees and the irrigation are doing to the same ground
An arborist and an irrigation technician are the two people most often left out of a drainage conversation, and both change the outcome. Tree roots follow water, and a trench cut through the root plate of a mature shade tree can cost you the tree several seasons later. An arborist can mark where a line may cross and where it must route around.
The irrigation tech matters because a controller running a fixed schedule will keep a low area saturated no matter how well the new drain performs. A rain sensor, a zone split, or simply shortening the run time on the affected zone often removes half the problem before any digging happens.
Run these five in order and you will usually find that the real fix is smaller and more specific than the first quote suggested. The puddle is information. It tells you exactly which trade to call first, and that call is the one that keeps the next round of planting in the ground for good.