My house doesn't have gutters or downspouts, so I'm planning to install them. Parts of the yard also remain wet for days after a rain, so I'm planning to install some kind of drain system in the yard (as well as fill in low spots, address slope, etc) to drain much of the water out to the front of the property.
The downspouts would tie in to the drain system, but should I install them first? Is it necessary for the downspouts to be present in order to tie them into the drains, or would I just need to know their likely locations?