1. Applicability and Purpose.

a. A Preliminary Drainage Plan shall be prepared for the following developments:

i. New nonresidential construction,
ii. New multi-family construction (3+ units),
iii. New residential subdivisions, or
iv. Conversion from single-family home to nonresidential/multi-family use when impervious surface is increased.
 

b. The Preliminary Drainage Plan shall show the watershed affecting the development and how the runoff from the fully-developed watershed will be conveyed to, through, and from the development.

i. The Preliminary Drainage Plan must comply with the standards outlined in this UDC, Engineering Criteria Manual, and other City codes.
 

c. The Preliminary Drainage Plan is a guide for later detailed drainage design.

d. The Preliminary Drainage Plan may satisfy the storm water management portion of the Storm Water Pollution Prevention Plan (SWPPP) that is required for construction activities; however, the Preliminary Drainage Plan is not a substitution for the SWPPP.

e. The review of the Preliminary Drainage Plan does not constitute final drainage plan approval or authorize a waiver to any of the Subdivision Regulations and Development Standards.
 

2. Plan Required and Previous Plans.

a. For any property involved in the development process, a Preliminary Drainage Plan shall be provided, at the Developer's expense, for the area proposed for development.

b. For property with a previously accepted Preliminary Drainage Plan, the accepted Preliminary Drainage Plan may be submitted and enforced unless a revised Preliminary Drainage Plan is required by the City due to lot reconfiguration or other conditions created by the new Plat.
 

3. Submittal.

a. Three (3) paper copies of the Preliminary Drainage Plan shall be submitted with the submittal of a Preliminary Plat or Replat for review and acceptance.
b. The Preliminary Drainage Plan shall be labeled as "Preliminary."
c. The Preliminary Drainage Plan shall be stamped by and dated by the engineer.