Let's compare:
Lake KremenchutskaArticle: 
Yes, they do. The hydroweb data is current.
Yes, but they didn't.
My claim is that the water level in the Khakova reservoir is controlled by the operators of the Khakova dam. I stand by this claim, because that's how river dams operate everywhere.
you have not shown evidence for the motives you find obvious (I don't)
No, I don't believe that. But I believe that the Khakova dam could have been opened to release as much water at the lower end of Lake Khakova as enters it at the upper end—as you point out, a not infinite amount. If your theory was true, all that needed to be sluiced from Khakova is as much water as was released from whatever reservoir upstream—both finite amounts. But there was no such release from the largest upriver reservoir.
Hydroweb uses satellite altimetry. You are proposing that Ukraine hacked multiple satellites, and that some reservoir levels are meters off their recorded values without anyone noticing, and nobody noticing a flood-like release from an upstream reservoir, either. And no evidence for any of it. That's a conspiracy theory fantasy, but not a serious explanation.
I don't. I said at least one sluice gate is probably damaged. But the gantries had been moving well after Ukraine attacked the dam, and there's no indication that most sluice gates aren't working. In any case, it'd have been up to Russia to get them working (and up to Ukraine to facilitate this if asked).
There was no benefit.
I have not suggested that the Russians would blow the dam to prevent an amphibious operation (that wasn't happening).
Let me help…
Crimea didn't have canal water 2014-2022. As I wrote above. It's not a good threat. But parts of mainland Ukraine also rely on irrigation from that lake, so it's a bit of shooting themselves in the foot.
That you haven't quoted.
That Crimea didn’t have canal water was indeed true. It was also one of the reasons for the invasion As evidenced by, quoting from Wikipedia, the Russians immediate objectives…
https://www.newsweek.com/ukraine-russia-dnipro-river-crossing-1796205
And if you look at any map of the russian fortifications eg https://deepstatemap.live/en#8/46.952/34.772
Article: Russia had means, motive and opportunity to destroy Ukraine dam, drone photos and information show
BERISLAV, Ukraine (AP) — Russia had the means, motive and opportunity to bring down a Ukrainian dam that collapsed earlier this month while under Russian control, according to exclusive drone photos and information obtained by The Associated Press.
Images taken from above the Kakhovka Dam and shared with the AP appear to show an explosive-laden car atop the structure, and two officials said Russian troops were stationed in a crucial area inside the dam where the Ukrainians say the explosion that destroyed it was centered. The Russian Defense Ministry did not immediately respond to a request for comment.
Article: Evidence is growing that Russia blew up Kakhovka Dam
A New York Times report Sunday said the Russians knew the weak spot in the Soviet-era dam, a passageway that ran through the concrete block at its base, and most likely detonated explosives there to create the breach.
“The evidence clearly suggests the dam was crippled by an explosion set off by the side that controls it: Russia,’’ said the Times, which cited engineers in reaching its conclusion and also said the American government subscribes to that theory.
Also Sunday, The Associated Press wrote that based on information and drone photos it obtained, "Russia had the means, motive, and opportunity to bring down" the dam.
Earlier in the weekend, a group of international legal experts helping Ukrainian authorities investigate the disaster said it was "highly likely'' the Russians blew up the dam, Reuters reported. The Washington-based Institute for the Study of War has also determined the Russians probably were behind the explosion.
Article: The dam was built with an enormous concrete block at its base. A small passageway runs through it, reachable from the dam's machine room. It was in this passageway, the evidence suggests, that an explosive charge detonated and destroyed the dam.
At 2:35 a.m and 2:54 a.m. on June 6, seismic sensors in Ukraine and Romania detected the telltale signs of large explosions. Witnesses in the area heard large blasts between roughly 2:15 a.m. and 3 a.m. And just before the dam gave way, American intelligence satellites captured infrared heat signals that also indicated an explosion.
As the water levels further dropped this week, they fell below the top of the concrete foundation. The section that collapsed was not visible above the water line — strong evidence that the foundation had suffered structural damage, engineers said.
Engineers cautioned that only a full examination of the dam after the water drains from the reservoir can determine the precise sequence of events leading to the destruction. Erosion from water cascading through the gates could have led to a failure if the dam were poorly designed, or the concrete was substandard, but engineers called that unlikely.
Ihor Strelets, an engineer who served as the deputy head of water resources for the Dnipro River from 2005 until 2018, said that as a Cold War construction project, the dam’s foundation was designed to withstand almost any kind of external attack. Mr. Strelets said he, too, had concluded that an explosion within the gallery destroyed part of the concrete structure, and that other sections then were torn away by the force of the water.
The seismic signals were picked up on two sensors, one in Romania and one in Ukraine, and occurred at 2:35 a.m. and 2:54 a.m. Ukraine time, said Ben Dando, a seismologist at Norsar, a Norwegian organization that specializes in seismology and seismic monitoring. The signals were both consistent with an explosion, Dr. Dando said — and not, say, the collapse of the dam on its own.
He said that the network could determine the time of an explosion to within a couple of seconds, but that the location of the blasts was less certain. For example, Norsar could locate the 2:54 a.m. signal to have originated within a zone 20 or 30 kilometers across that included the dam.
Professor Baecher said it was possible, though unlikely, that water flow from the damaged gates somehow undermined the concrete structure where it sat on the riverbed. But he said an examination of the drawings indicated that the design had protected against that possibility with standard measures. One of those is a so-called “apron” of concrete on top of the riverbed to the downstream side of the dam.
“This appears to be a well-engineered dam of modern design,” he said.
Neither this previous damage, nor the pressure caused by the high water level or the static position of the cranes is likely to have caused the collapse of the dam’s concrete foundation, experts said, unless the concrete was of low quality and already prone to deteriorate. The large flows would also be insufficient to undermine the dam’s foundation unless, for some reason, the concrete apron — the downstream cover placed over the river bottom — contained flaws or the soil was much softer than accounted for in the design.
A video that emerged this week, after water levels had dropped, provides clear evidence of the catastrophic failure. It shows that the top of the concrete foundation, not just the gates, was destroyed.
