the fix is a easy one. you only have to ditch from the delta through laguna salada. From there the water would feed down hill to the sea. its pretty simple to be honest but would require cooperation between usa and mexico.
You can not have outflow from the sea. besides the obvious 230' bellow sea level and having to pump it all the way to the gulf. The lets just pump it to the Colorado river and fuck mexico sounds great till you understand that we already fuck mexico and let almost none of the water that comes down the river into mexico. What little we do let over is for farming and drinking water and very very tiny amount goes into the delta. pumping sea water into the river would destroy what is left of greatest wetland the modern world has ever know. so pretty sure mexico is not going to let us dig a ditch to bring sea water and and let us dump hyper saline water back wrecking the delta.
there is no comparison between the TJ river and the damage WE do to the mighty Colorado. We wrecked something amazing and as people we should all be sad.
On the map the delta was bisected by the river, but in fact the river was nowhere and everywhere, for he could not decide which of a hundred green lagoons offered the most pleasant and least speedy path to the gulf. So he traveled them all, and so did we. He divided and rejoined, he twisted and turned, he meandered in awesome jungles, he all but ran in circles, he dallied with lovely groves, he got lost and was glad of it, and so were we. For the last word in procrastination, go travel with a river reluctant to lose his freedom in the sea.
— Aldo Leopold, A Sand County Almanac