Thank you for your feedback!
My advice would be to make sure that you have enough money to make the next days payment before building any new blocks/upgrades. However, a couple of businesses shoud leave you in a good position by day 10. Are you building enough housing? Businesses don't make as much money without adequate housing because of a lack of workers.
Yes, multiple resevoirs are needed as your population increases. The population only increases with sufficient housing/jobs so again, lack of housing maybe? It is definitely win-able!
I've added an easy mode in the last update which will hopefully help getting a hang of the game!
Please feel free to email me with any other questions, hope this helped :)