Board of Supervisors Meeting Date: 

Cliff Mills, LLC (Owner)
John A. Ennis, Jr. (Applicant)

May 14, 2009

Staff Lead:


Melissa Dargis, Assistant Chief of Planning

Community Development


Magisterial District:



Service District:


A Resolution to Approve a Category 23 Special Exception (SPEX09-MA-016) to Allow for the Construction of a Private Pond for Agricultural Use Within the Federal Emergency Management Agency (FEMA) 100-Year Floodplain


Topic Description:

The applicant is seeking to construct a pond on his property to provide a water source for agricultural crops, including but not limited to grapes and trees.  The farm consists of approximately 359 acres that is in two separate parcels.  The pond will be approximately 4.2 acres in size.  The applicant has selected this particular location for the pond as there is no other suitable location on his farm.  He has been farming for twenty years.  The long term plan for the property is the establishment of a vineyard and native tree farm.  The topography of the land lends itself well to the proposed use because there are several upland pasture areas for crops and low lying areas in the central portion of the property make this an ideal location for an irrigation pond as it will be close to crops.

Watershed Consulting, PLLC, the applicant’s consultant said the proposed pond location also will include an adequate drainage area.  The existing stream is severely incised and degraded due to cattle and erosion.  The pond will replace this degraded stream section and serve as a sediment basin, thus limiting downstream erosion.  Their review of the topography, water resources, and plans for the property support the location of the pond.  No other location on the farm could provide the adequate volume to meet the irrigation needs of the grape and tree crops.


Location,  Zoning and Current Land Use:

The property is located at 9400 Cliff Mills Road.  It is zoned Rural Agricultural (RA) and Rural Conservation (RC).  It is in agricultural use.  A map of the property is shown below:


Surrounding Zoning and Current Land Use:

Surrounding parcels are zoned RA/RC and are predominately in agricultural and forestal uses. 

Staff and Review Agency Comments: 

Staff and appropriate referral agencies have reviewed this request for conformance with the Comprehensive Plan, the Zoning Ordinance, and other relevant policies and regulations.  Findings, comments, and recommendations are summarized below. Following each comment is a staff note in italics stating how the comment has been addressed.

Planning Office

The applicant has met the requirements of the Zoning Ordinance Section 5-006, General Standards for Special Exception Uses.  General standards for all Special Exceptions require that the proposed use will not adversely affect the use or development of neighboring properties, will not conflict with existing traffic, and other such criteria to protect the surrounding environment.  In this case, the proposed pond will not cause degradation of the surrounding area or add traffic.

In addition, the applicant indicates that the following applicable standards for floodplain uses have been met with the proposed project:

5-2301                         Standards for All Category 23 Uses

1.   No such use shall cause an increase in the level of flooding or velocity of flood waters.

A drainage study will be required to demonstrate this standard.  A Special Exception condition has been drafted to that effect.

2.   No such use shall create a potential hazard of debris subject to movement by flood waters which might cause damage downstream.

A drainage study will be required to demonstrate this standard.  A Special Exception condition has been drafted to that effect.

3.   The John Marshall Soil and Water Conservation District (JMSWCD) shall be given the opportunity to comment on such uses.

This application is exempt from JMSWCD review since it is for agricultural use.

4.   The applicant shall have obtained and shall present evidence attesting any applicable approvals by State and Federal authorities concerning such a use.

A Special Exception condition has been drafted to this effect.

5.   Materials and equipment stored in the floodplain shall not be buoyant, flammable or explosive, and shall not be subject to major damage by flooding or such materials and equipment must be firmly anchored to prevent flotation or movement and/or can be readily removed from the area within the time available after flood warning.

Not applicable to this project.

6.   Special exceptions shall only be issued after the Board of Supervisors has determined that the granting of such will not result in (a) unacceptable or prohibited increase in flood heights, (b) additional threats to public safety, (c) extraordinary public expense, (d) create nuisances, (e) cause fraud or victimization of the public, or (f) conflict with local law or ordinances.

If approved, and subsequent to the adequate drainage study approval, this Special Exception will not result in an increase in flood heights, additional threats to public safety, extraordinary public expense, create nuisances, cause fraud or victimization of the public or conflict with local laws or ordinances.

7.   Special exceptions shall only be issued after the Board of Supervisors has determined that the special exception will be necessary to provide the applicant with reasonable use of the parcel of land in question, taken as a whole.

Due to the volume of water required for grape and tree crops, the applicant indicates he needs a pond of this size and in this location.

8.   The Zoning Administrator shall notify the applicant for a special exception in writing, at the time of filing, that the issuance of a special exception to construct a structure below the one hundred (100) year flood elevation (a) will increase risks to life and property, and (b) will result in increased premium rates for flood insurance.


9.      A record of the above notification as well as all special exception actions, including justification for their issuance, shall be maintained and any special exceptions which are issued shall be noted in the annual report submitted to the Federal Insurance Administrator.



The Engineering Department has reviewed the above referenced Special Exception to construct a private pond in the Federal Emergency Management Agency (FEMA) Zone A floodplain and has the following comments:

Conditions of Approval

  1. A drainage study shall be provided demonstrating that the construction within the floodplain will not adversely affect the capacity of the channels of any water course, which would increase flood heights and/or velocities on adjacent or downstream properties.
  2. The applicant shall assure that all applicable environmental permits have been acquired.  This includes the U. S. Army Corps of Engineers/Department of Environmental Quality (USACE/DEQ) permits for disturbance of wetlands or other regulated waters.

Special Exception conditions have been drafted to this effect.


  1. The proposed dam height is shown as 14.5 feet.  Please be advised that impounding structures, which have a height greater than or equal to 15 feet and up to 25 feet, shall conform to all design criteria listed in the NRCS Pond Specification Number 378 in accordance with the County Zoning Ordinance 6-102 #24.

Information for the applicant.


  1. Zoning Staff confirms the following:

a.   Property is zoned RA/Rural Agricultural;

b.   The proposal to build a pond, with structures, in the floodplain requires special exception approval pursuant to §3-323.

2.      The proposed applications for special exception must be evaluated pursuant to the following standards in the Zoning Ordinance:

a.   §5-006 General Standards for All Special Exceptions;

b.   §5-2301 Standards for All Category 23 Uses.

Zoning Staff defers to Planning Staff for the evaluation of the special exception standards.

See earlier analysis of these standards.

3.      In addition to the standards listed under #2, above, the proposal is subject to the Use Limitations for all floodplain uses set forth in §4-407.   Staff is unable to determine whether the proposal meets limitation 3 of this section, which states:

“Under no circumstances shall any use, activity, and/or development adversely affect the capacity of the channels or floodways of any watercourse, drainage ditch or any other drainage facility or system which would increase flood heights or velocities.”

The applicant will have to demonstrate compliance with this limitation through a drainage study, prior to construction of the pond.

A Special Exception condition has been drafted to this effect.


4.      A Zoning Permit is required to be approved prior to pond construction.

Information for the applicant.

5.      Although shown to do so on the plan submitted with the application, the pond may not meet the Zoning Ordinance requirement that the pond be located so that the 100-year flood pool and spillway is located not less than 50 feet from an adjacent property (§6-102.24(C)).  The details shown on the submitted plan appear in conflict and suggest that the pond may actually be closer to the northern property line than shown, given the identified dam and spillway structures. The plan shows the dam impoundment to elevation 355, and the emergency spillway also located just above elevation 355, suggesting that the day-to-day pond elevation will be about 355, with the 100-year flood pool somewhat higher.  However, the pond elevation is shown under 355, with the 100-year flood pool at 355.  It is possible that the height of the impoundment will need to be lowered in order to meet the setback requirements. 

Proposed condition:

The height of the dam shall be lowered to the extent necessary to meet the Zoning Ordinance requirement for a minimum 50 foot setback of the 100-year flood pool elevation from the property line.

            A Special Exception condition has been drafted to this effect.

Virginia Department of Health

It appears that dwellings and their supporting development, such as water wells, and drainfields/reserves are not affected by this proposal.

The stand-off distance from impounded waters to drainfield components and reserves is 100 feet.

If there are buildings served by on-site sewage disposal systems that might be affected by this stand-off to the proposed pond, they should be identified on the applicant’s plat to insure the 100 foot stand-off is met.

Information for the applicant.


Findings Based on the Official Soil Survey:

  1. 6% of the site is rated as prime farmland.
  2. 24% of the site is rated as statewide important farmland.
  3. 5% of the site has the potential for hydric soil inclusions, indicating the possible presence of jurisdictional wetland.
  4. 99% of the site is rated as “Very Limited” for pond reservoir area, with slope and seepage as the main limitations.

Information for the applicant.

Planning Commission Summary and Action of March 26, 2009:

The Planning Commission discussed this item at its work session.  A public hearing was held on the application.  The applicant’s representative indicated willingness to comply with revised conditions related to stream buffers.  The application was forwarded with a unanimous recommendation for approval, subject to revised development conditions.

Summary and Recommendation:

This application for an agricultural pond in the FEMA 100-year floodplain has met the conditions set forth in Zoning Ordinance Sections 5-006 General Standards for All Special Exceptions and 5-2301 Standards for All Category 23 Uses. 


Requested Action of the Board of Supervisors:

Conduct a public hearing and consider adoption of the attached resolution.

Identify any other Departments, Organizations or Individuals that would be affected by this request:

Department of Community Development


1.          Statement of Justification

2.          Special Exception Plat


Back to Agenda...