If homeless people cannot camp on public land, where do TPTB think they should go?
And who do they think the public land belongs too, anyway?
Here, there are huge blighted industrial areas/sites, which have the utility infrastructure, and sometimes the security infrastructure, to support large encampments so that sanitation, safety, etc. can be maintained. There's one particular place here that would be ideal, and the bus line could be diverted a couple of blocks at one point to the existing gate, and then back to the normal route, so people there could go to work, appointments, etc. If social services, employment services, day hire, basic and urgent medical and mental health services, detox and rehab pick-up, etc. were set up to be provided 24/7 on-site, people could actually get needed help and get on their feet. If the people in the encampment were empowered and provided with resources to enforce the rules and provide at least some of the necessary services and self-governance for themselves, instead of everything being done "to" them, cooperation and "ownership" of the situation would further eliminate a lot of "encampment-related issues." An elected governance council among the homeless residents, which meets in conjunction with the people running the camp makes a huge difference, and allows problems to be prevented and resolved (and stay prevented and resolved) better.
The biggest infrastructure needs for a well-run encampment are 24/7 security (both in the encampment and outside to keep the drug dealers and thieves out/away, and a big fence with security and referral to services at the gate), generous water, and generous sanitation (rest rooms, waste disposal, garbage pick-up, recycling, etc.). Clean, well-stocked restrooms, showers, and laundry facilities, all with paid attendants, make a HUGE difference and prevent extortion, abuse, theft, and assault in those facilities, and permit homeless people a LOT of dignity and incentive/ability to go to work, etc. No one wants to go anywhere if they or their clothes smell bad. Electricity and SAFE heaters are absolutely needed, especially in winter here. Otherwise people resort to fires to stay warm, which is a huge safety issue. Some form of secure, climate-controlled storage is also necessary, so people don't lose valuables (including work tools) and important papers to theft or the elements. Free wifi is also needed for education, job search, medical/mental health services/access to information/records, contact with family/friends, etc.
Churches, missions, etc. need to either conduct worship services on-site, or provide transportation to and from. Daily worship services and Bible study are essential, as spiritual needs among homeless are huge, and it's frustrating to not have access on a day(s) when one is available to go. It's very time-consuming and exhausting to exist as a homeless person, and available jobs with employers willing to hire homeless often preclude church or Bible study at "normal" times.
The harm reduction model is only good for the people, who already have the problem, and this has to be absolutely 100 percent strictly segregated from everyone else, otherwise, it becomes a harm-spreading model. I have seen this up-close-and personal, and it is a big reason why one of my siblings is now on drugs and mixed up with wicca, etc. This includes smoking vs non-smoking areas, which are separated so that non-smokers are protected. Some mental illnesses and emotional issues are helped by smoking (tobacco or marijuana, depending on the issue), so an absolute ban doesn't work, and vaping must also be banned in the non-smoking area(s).