I’m not sure how transpiration + evaporation from worst case irrigation situations compares to ocean evaporation? Given that under some circumstances water vapor builds up as ice at the poles, MAYBE irrigation could add to long term ice buildup at the poles at the expense of the oceans. But, there’s no indication such circumstances are in play now.
Pulling large amounts of salty groundwater out for desalinization may have unintended side effects, though probably less so than pulling out too much fresh ground water.
Your posts remind us that the real problem is not a water shortage - it’s just where the water is or is not that is problematic. The Mississippi River south of it’s confluence with the Ohio River passes some 240 million acre-feet of water (and a little debris) annually.
You are right ice and ground water recharge are the only two stores of water that doesn’t end up back in the oceans nearly immediately. Ground water near the coasts flows by subsurface flows down hill to the coastlines and eventually out under the continental shelf back into the oceans it’s a lot slower than river transport. There are places you can still 50 plus miles offshore and hit fresh water under the sediments. Off shore Florida the ground water flows are so high they boil up to the surface miles off shore you can see the density difference and even drink the water in the middle of the boils. In the 1700 and 1800 sailors would look for those boils off shore to get fresh water to drink all over the Florida shelf, Cuba and the Bahamian banks. Ice is the other storage Continental ice sheets specifically they currently hold 20 % of the freshwater that is not in the oceans or ground water.
Pumping deep saline aquifers can cause subsidence at the surface we see this all over Midland basin where oil and brines are pumped up for frac fluids. Has a flat a pair of radar says you can get high rez inferometric images with cm vertical resolutions that show mass subsidence. That and the big sinks holes that periodically open up in that basin.
As to Mississippi water back when the USA was a can do engineering powerhouse the plan was to pump MS water up hill 3000+ feet to Texas and New Mexico. Check this.Mega engineering out.
https://www.twdb.texas.gov/publications/State_Water_Plan/1968/1968_Texas_Water_Plan.pdf