Ayden Court Special Use Permit and Rezoning Request

Chapel Hill Planning Board Meeting

September 2, 2008

My major concerns about Ayden Court are summarized below.

1. The Comprehensive Plan shows open space as the recommended land use for this property. Hence, I do not agree with the applicant's position that the project conforms to the Comprehensive Plan since open space would be replaced with housing.

2. The project is located immediately adjacent to the Army Corps of Engineers Jordan Lake Watershed Property. This property is a significant waterfowl habitat. Changes in the use of the adjacent property will increase the volume of stormwater entering this property and will also increase the stormwater pollutant load entering the property. Impacts on waterfowl are foreseeable.

3. The applicant maintains they will conserve and protect the natural setting of Chapel Hill and elaborates this point by stating that the adjacent land, also called the Upper Little Creek Waterfowl Impoundment Area, wil be protected by a combination of factors including the high stormwater standards adopted by the Town. I disagree that they will meet this requirement. Although the Town has adopted state recommended stormwater standards, those standards do not require that post-construction stormwater water quality and quantity be equal or better than pre-construction standards.

Instead, the standards require that pre- and post-construction stormwater runoff for a two year storm be unchanged. However, for a more significant rainfall (somewhat more than two inches over a defined time interval), new developments such as Ayden Court must just design to contain stormwater flow to protect the public safety, not to avoid downstream increases in water quantity. So for a five year storm (i.e., a larger amount of rainfall that typically falls every five years), the waterfowl impoundment will see increased flow. There is philosophical debate in the scientific community that these five, 25, and 100 year heavy rainfalls are occurring at shorter intervals than their named frequency meaning that, if anything, the number of severe storms impacting the waterfowl impoundment may be increasing.

Water quality will also be changed. Right now, Chapel Hill only requires that a relatively high percentage (85%) of sediment be removed prior to discharge of stormwater. Still, not all sediment is removed. This will cause the nearby waterfowl impoundment to slowly fill with sediment over time. In manmade stormwater detention ponds, maintenance including periodic removal of sediment is required. In the case of Ayden Court, they are not required to clean outside their property limits.

Chapel Hill presently doesn't require that other common pollutants found in stormwater such as nitrogen and phosphorus be removed. The construction of Ayden Court will likely increase nitrogen and phosphorus in stormwater compared with current conditions since these are the two active ingredients in fertilizer. Fertilizer would be expected to be used on the landscaped areas where now it is not.

Jordan Lake has been identified as a nutrient sensitive lake with the worst area that at the New Hope Creek discharge area. Ayden Court will drain into the waterfowl impoundment which drains into New Hope Creek. The nitrogen and phosphorus can cause increased algae and algal blooms in the waterfowl impoundment and exacerbate algae and other related problems in Jordan Lake. The algal plant cycle also lowers dissolved oxygen which adversely affects fish populations.

Ayden Court petitioners state that they plan to capture stormwater for irrigation reuse. Although water reuse is encouraged and will potentially lessen the nitrogen and phosphorus discharge into the adjacent waterfowl impoundment, the simple math of stormwater capture and reuse shows that 100% recycle does not occur. In addition, once the stormwater storage areas fill, additional stormwater will flow through the system into the impoundment. This is particularly significant during months in which irrigation isn't applied (winter months) or during times of sufficient rain when irrigation isn't needed.

In summary, I am opposed to making an exception to the comprehensive plan by allowing an exception to the land use plan because this project has not shown any compelling reason why such an exception should be made. Further, the project represents a significant potential of harm to the adjacent preserved area and wildlife habitat because of increased pollution loads including sediment, nitrogen and phosphorus.

Judy Weseman

Planning Board Member