Enough to be substantial in proportion to the cost of establishing this kind of enterprise, and committed rather than reserved. The practical budget includes equipment, yard, licensing, bonding, insurance and the working capital needed before the first invoices are paid.
A start-up is measured against what starting one costs
Hypothetical example: the partners set aside a figure they heard was required, then find that establishing the business consumes more than that before any revenue arrives. Cost the enterprise properly: yard and premises, trailers and towing equipment, augers and welders, tooling, initial materials, vehicle purchases or leases, contractor licensing, bonding, insurance, and payroll for the first crews before receivables turn over. That total is the denominator against which substantiality is judged.
Show what proportion of it the investors have committed and evidenced with invoices and transfers. Keep operating projections on a separate page from committed capital. Government amounts for the application itself are published by the responsible agency and are minor beside these figures, but legal and accounting advice on both sides of the border is not.