Dear Ram,
Thanks for your observation, which is relevant and important. May I explain?
Firstly, a surplus budget is not
per se bad nor abnormal practice. In our country, the Railways Minister has presented a budget with a surplus of Rs. 20,000/- Crores.
Our surplus comes from accessing BDA funds. In the third revision of the cover note addressed to BBMP, I have added more explanations which should clarify most of the questions regarding source of funds etc. I shall be uploading this just now. Kindly go through this and see if your query is answered reasonably well.
Your are certainly right that these funds should not be idle, but be invested. I believe that the Govt would be investing these in some securities. It is not necessary to spend all surpluses.
The Govt's CDP document has also made use of these very funds to indicate the means of finance.
The BDA is to be dissolved when the new governance structure is operational. In fact under the KMC Amendment Act 1994, BDA should have been done away with long back and a Metropolitan Planning Committee constituted.
Warm regards,
Mathew