I am a parent with 2 children in college, one 17-year-old in high school, and one out in the world as an independent adult.
I confess that unlike you, I have almost forgotten what it is like to have really young kids (10 and under). So, looking back, I am almost totally supportive of K-12 closures. But I am having very mixed feelings about college dorm closures. I think the country would be better served by not closing colleges. Here are my thoughts:-
College students are adults, young and immature though they may be. The college dorm or housing is the real home of a college student. That is where they go every night, except once every 3 months when they may come back to their parents' home. Even more important than the formal education they are getting, they are learning how to live as independent adults, and to become contributing members of the broader community. They are also in the process of pair formation, and socializing is a very important part of their life. So my first fear about college closures is creating conditions for a "failure to launch" (remember that movie?).
With respect to our problem with the coronavirus, if still in their college housing they would be interacting almost exclusively with other young adults, who supposedly have a low risk of hospitalization. If you push them back to their parents' home, you are going to have a lot of bored young adults, who will wind up going out into the wider world a lot more than grade school kids who are being kept home, or even those same students when busy with their studies and at college. Every day they are home, given what is driving them, we risk 20 million of them scattered all over the country (and world) - instead of far fewer college campuses - bringing back the virus to elderly or vulnerable relatives with a high risk of hospitalization.
I think it would be better for the country, and for them, to keep their college housing open and let them stay there. Faculty (another high risk population) can be protected by having either online only classes, or by eliminating in person office hours and direct contact. A large lecture hall normally has a separate entrance for the lecturer, and anyway the students are way more than 6 feet away during a lecture.
I did read the Imperial College modelling simulation paper on which we seem to have based our current national strategy; and noticed the table of IFRs on Page 5 showing the risk by age groups. The biggest problem I have with it is that it seems DESIGNED to push government into taking the total shutdown route. Hopefully by now you have your own team doing some modelling too. If so, I think you should ask them to go back to current raw data, and first do a breakdown, and a model, more useful to your decision making - like using age groups more relevant to life in California; e.g. 0-4 (preschool), 5-18 (K-12), 18-25 (college students and single young adults), 26-55 (working adults with children at home), 56-65 (near retirees), 65+ (retired seniors).
With a breakdown like this, you can come up with more intelligent strategies to deal with the coronavirus in California. For example, you can use the grace provided to young people by the risk profile of this virus.
Using the data from the above paper, even if the ENTIRE student body of 60000 of a community like UC Davis was infected, using the worst case numbers (IFRs for 20-30 age group) there would be ~18 deaths, ~36 ICU cases, and ~120 hospitalizations over a 3 month period - something the Davis hospitals could handle (~6 ICU beds, ~15 other beds). In the next year, we would only be looking at 15000 incoming freshmen (0-20 age group) - ~1 death, ~2 ICU cases, ~6 hospitalizations. The rest would already be exposed and immune. Given what is happening with the numbers since the paper was published, improved testing, and a proper breakdown, these numbers would be significantly smaller. But we would have taken the riskiest social distancers out of the general community, AND the most pressing needs of this age group would have been met.
Also, I live near UC Davis, and have had many opportunities to talk to students. It seems a lot of students (and I) had some nasty unknown bug around the mid-January timeframe, and are probably already immune to CoVID19 as a result. There is a test developed in Singapore that can tell whether somebody has been exposed in the past and has antibodies to CoVID19; unlike our current swab test that tells whether somebody is actively infected and shedding virus. So every semester end, the health system near a college can gear up for mass testing, and release students to go back to their parents' home if they pass both tests. If they fail the current swab test they go into mandatory quarantine before they go back. If they pass the swab test, they can take the antibody test. If they have antibodies they can have confidence that they are immune, can contribute to things like your Healthcare Corps during the summer (which they want to do!), and the CDC will have more information about how many have already been infected. If they do not have antibodies, they can self quarantine to make sure they do not have a latent infection before returning.
At some point to go back to normal our country will need to accept the disease as part of our lives. That will be when we have developed "herd immunity", either through vaccinations or prior infection. So I hate to say it, but keeping them in college housing would also give our country a relatively low risk way of getting a head start into developing the necessary "herd immunity" and getting back to normal.
I hope that you can fine tune your guidance to California colleges after discussing these thoughts with your epidemiologists, sociologists, and modellers. Be safe.