Naomi,
As you likely know, these funds should have started being raised years ago. To correct this issue going forward, make sure your Association has a reserve study done and properly fund the Reserves based on the study. For more info on reserve studies see the following thread in this forum:
Subject: Reserve Studies/Funds 101 Now to reply to your specific questions on how to raise $600K over 3 years, there is only two ways and neither one will be appreciated by the membership. These are:
1) Special Assessment payable over three years
2) Borrow the money and raise the assessments to pay back the loan.
Keep in mind that money for anything will only come from the membership.
There will be two camps, those who believe this is what we must do and those who won't want to pay anything.
Depending on how large your Association is, a special assessment may be worthwhile.
A 2,000 lot community would equate to $300 special assessment
A 500 lot community would equate to $1,200 special assessment and you may have push back from the members.
There are other options you may or may not have considered.:
1) Defer repairs to allow more time (but may result in higher costs)
2) Have a MC or Reserve Specialist firm solicit bids for you (vs. the Association soliciting bids). This may result in lower costs per square yard. The reason being that a MC or other firm will have other work available and contractors will offer better prices in hope to get additional work the following year. Contractors will likely see your Association as a one time job - repeating in maybe 15 years. Example: We paid for a reserve study last year. Our quote for road replacement was $14 square yard. The specialist told me that this is high as they just bid out similar jobs and were getting quotes for $11 square yard. At 10,000 square yards, that equates to a difference of $30,000. The difference being that they can offer repeat business to the contractors.
Personally, I'm against obtaining a loan as the membership will then not only have to pay the initial amount but the interest (which just makes the cost of the job higher).