Very well Preetam Singh! You got the answer correctly.
The desert is this world and the garden is Siri Guru Granth Sahib jee, the only source of relief in this world. The zones are the different Raags in Guru Sahib and the particular ponds mentioned in this story are the 22 Vaars.
There were many hints in the story that alluded towards the 22 Vaars. It was mentioned that 3rd and 5th zones have 2 ponds each. The 3rd zone is Raag Gauri which has 2 Vaars - Mahalla 4 and Mahalla 5. The fifth zone is Raag Gujri and this Raag too has two Vaars - Mahalla 3 and Mahalla 5. Another zone or Raag that has 2 Vaars is Raag Maaroo. The lucky Raag that has 3 Vaars is Raag Ramkali.
The Mehima or greatness of the Vaars is beyond description. What should one write and where should one begin writing about them. The pre-requisite to having Anand of 22 Vaars is Santhiya. If one is not fluent in 22 Vaars, then it is hard to derive maximum Anand because then it's even hard to do Paath (due to very Mehingi (difficult) Baani) let alone understand it.
The hardest Vaars are of Raag Maajh, Raag Gujri Mahalla 5, Raag Jaitsree, Raag Maaru Dakhne, Raag Saarang and Raag Malaar. Rest of them are intermediate or easy to read.
Someone asked a question recently as to how to become an Akhand Paathi. Well, one can't be classified as an Akhand Paathi if one is not fluent in all 22 Vaars and Bhagat Baani. So, one should focus hard on these Baanis to become a successful Paathi.
When Bhai Sahib Randhir Singh jee first came into Sikhi, he became a Baavra (Divaana, crazy) by reading 22 Vaars and Bhagat Baani, day and night. He used to lose consciousness while doing these Paaths and even in his class he used to read 22 Vaars and Bhagat Baani, instead of focussing on his studies. From this we learn that if we want to have Darshan of Vaheguru jee, we too should get into some crazy Paath of Punj Granthi, 22 Vaars, and Bhagat Baani.
It is possible to do 22 Vaars everyday for few days. If that's hard, one can attempt to do 22 Vaars within a week or even in 22 days i.e. one Vaar a day. Then one can switch to Bhagat Baani in the same way. Punj Granthi should be done every single day, no matter what. This is for such people who are serious of Darshan of Vaheguru jee and ones who don't want to come back in this world again.
Below is a chart that can be of help to those lucky seekers of Vaheguru, who want to do Paath of 22 Vaars. This chart shows the Ang information of 22 Vaars. It is beneficial to do 22 Vaars from Siri Guru Granth Sahib jee or Senchis of Guru Sahib as opposed to the Pothis that have only 22 Vaars because this way the Vaar Naqsha (mapping) as it appears in Siri Guru Granth Sahib jee, becomes impressed on the mind.
Bhul Chuk dee Muaafi jee.
Kulbir Singh