1. A. The watersheds specified in this regulation are interjurisdictional in nature and have documented flood damages to residential, commercial, industrial, or institutional structures. Development in the interjurisdictional flood hazard watershed may not increase the downstream peak discharge for the 100-year frequency storm event. Additionally, development shall comply with flood management plans as approved by the Department in accordance with the Flood Hazard Management Act of 1976 (Environment Article, Title 5, Subtitle 8, Annotated Code of Maryland). The following watersheds and all their tributaries are designated as interjurisdictional flood hazard watersheds:

   1. (1) Carroll Creek in Frederick City and Frederick County;
   2. (2) Gwynns Falls in Baltimore City and Baltimore County; and
   3. (3) Jones Falls in Baltimore City and Baltimore County.

2. B. The Administration shall periodically review watersheds to be included as interjurisdictional flood hazard watersheds for the purposes of this chapter. Any additional interjurisdictional watershed to be designated will be considered with respect to the:

   1. (1) Economic losses due to flood damages;
   2. (2) Expected upstream development;
   3. (3) Frequency of flooding;
   4. (4) Number and value of structures flooded; and
   5. (5) Threat to life.

Authority: Environment Article, §§4-201 and 4-203, Annotated Code of Maryland

Effective date: July 18, 1983 (10:14 Md. R. 1260)

Regulations .03A, and .08A, C, and G amended effective June 4, 1984 (11:11 Md. R. 962)

Chapter recodified from COMAR 08.05.05 to COMAR 26.09.02

Chapter recodified from COMAR 26.09.02 to COMAR 26.17.02, June 1996

Chapter revised effective October 2, 2000 (27:19 Md. R. 1733)

Regulation .01 amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .01D adopted as an emergency provision effective April 7, 2010 (37:10 Md. R. 719); adopted permanently effective July 26, 2010 (37:15 Md. R. 1001)

Regulation .01-1B amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .01-2 adopted as an emergency provision effective April 7, 2010 (37:10 Md. R. 719); adopted permanently effective July 26, 2010 (37:15 Md. R. 1001)

Regulation .02B amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .03 amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .04B amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .05 amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .05C, D amended as an emergency provision effective April 7, 2010 (37:10 Md. R. 719); amended permanently effective July 26, 2010 (37:15 Md. R. 1001)

Regulation .06A, B amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .08 amended effective May 4, 2009 (36:9 Md. R. 652); July 29, 2019 (46:15 Md. R. 656)

Regulation .09E amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .09F adopted effective July 29, 2019 (46:15 Md. R. 656)

Regulation .10 amended effective May 4, 2009 (36:9 Md. R. 652)

Regulation .11A, B amended effective May 4, 2009 (36:9 Md. R. 652)