A. 
Stormwater drainage systems shall be provided in order to permit unimpeded flow along natural watercourses, except as modified by stormwater management facilities or open channels consistent with this chapter.
B. 
The existing points of concentrated drainage that discharge onto adjacent property shall not be relocated and shall be subject to any applicable release rate criteria specified in this chapter.
C. 
Diffused drainage or flow.
(1) 
Areas of existing diffused drainage discharge shall be subject to any applicable release rate criteria in the general direction of existing discharge, whether proposed to be concentrated or maintained as diffused drainage areas.
(2) 
If diffused flow is proposed to be concentrated and discharged onto adjacent property, the developer must document that adequate downstream conveyance facilities exist to safely transport the concentrated discharge, or otherwise prove that no erosion, sedimentation, flooding, or other harm will result form the concentrated discharge.
(3) 
Where a development site is traversed by watercourses other than permanent streams, a drainage easement shall be provided confirming substantially to the line of such watercourses. The terms of the easement shall prohibit excavation, the placing of fill or structures. And any alteration that may affect adversely the flow of stormwater within any portion of the easement. Also, maintenance and mowing of vegetation within the easement shall be required.
D. 
Any stormwater management facilities regulated by this chapter that would be located on state highway rights-of-way shall be subject to approval by the Pennsylvania Department of Transportation (PennDOT).
E. 
Any stormwater management facilities regulated by this chapter that would be located in or adjacent to waters of the commonwealth or potential wetlands shall be subject to approval by PA DEP through the joint permit application process, or, where deemed appropriate by PA DEP, the general permit process. When there is a question whether wetlands may be involved, it is the responsibility of the developer or his agent to show that the land in question cannot be classified as wetlands, otherwise approval to work in the area must be obtained from PA DEP.
F. 
When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainageways shall be subject to approval by PA DEP, through the joint permit application process or, where deemed appropriate by PA DEP, through the general permit process.
G. 
Sinkholes. Stormwater resulting from land development activities shall not be discharged into sinkholes.
H. 
Proposed stormwater development shall not increase the one-hundred-year flood water surface elevation for floodplain areas within or affected by such development.
I. 
Erosion and sedimentation plan approval must be obtained from the Washington County Conservation District.
J. 
Any additional state, federal, or other governing authority or approvals not specifically mentioned in this chapter required as a result of the proposed stormwater developments must be obtained.