From what I read in the Japanese language press they will either be building a higher seawall (by September) and/or more effectively pumping out the contamination to a below legal standard before it reaches shore.
All their plans to date have fatal flaws in them. Since they built the plant over an aquifer, 1,000 tons of water flows through the ground under the plant and enters the sea. About 400 tons per day has been released that was highly contaminated.
Their first plan was to build glass walls on the seaside of reactor 2. The wall is almost done and guess what. The ground water rose up to and over the height of the underground wall. And it has caused all the water around the plant to have higher contamination levels.
There second plan is to pump up the ground water on the inland side of the plant and dump it into the ocean before it gets contaminated. Unfortunately the ground water flow system works on pressure. If they pull up 600 tons, 600 tons quickly flows in to replace what they pulled up.
They built the darn thing over an aquifer where water from the mountains inland flow to the sea underground. To handle this flow around the plant before 311, they had 59 sub drain pits around the buildings that they used to affect the underground water pressure. All of those pits became contaminated and crippled on 311. Half of the 59 pits can not be accessed. The other half are highly contaminated. They are building new pits and plan for 13 eventually. However, the contaminated water problem is escalating now almost out of control. They may need to seek kamikaze workers to get the highly contaminated pits operational. Kamikazi means Gods Wind. It is how Japan has been defended over the centuries.