Sandoval County and Cashwell Developers Game Placitas

Sandoval County and Cashwell Developers Game Placitas

by Bob Gorrell

November 22, 2011

Over the years Sandoval County has enjoyed the ever increasing downhill flow of cash from the property tax rich Placitas Area.  It has a new plan to speed this flow by increasing the density of homes and without regard to existing residents.  If you have not yet been aware of the new and loosely drafted Clustering Ordinance, it is time to pay attention as you may soon have one of these developments next door to you.

In what follows, I will show that the Cashwell cluster housing zoning application creates an average density about 450% greater than existing surrounding housing densities.  Unfortunately, this is being accomplished through the proverbial devil in the details.  The Sandoval Planning and Zoning Commission had planned to continue to hear comment and deliberate on the Cashwell Application, that seemingly already has staff approval, on Thursday, December 8, 2011 at 6:00PM.  However that meeting has been postponed, and the next PZC meeting is scheduled for January 12, 2012.  It is not sure at this time if the Cashwell Application will come up for hearing then.

A major question concerning any application for Cluster Housing Special Use zoning is this: What is the maximum number of clustered housing units allowable on the specific property?  This question must presently be answered by the Sandoval County Planning and Zoning Commission (PZC) and the County Commission, due to the present Cashwell application to re-zone for 65 clustered housing units on an 87 acre property.  The Sandoval County Zoning Ordinance (SCZO), approved by the Sandoval County Commission in April, 2009, lacks adequate specifics to answer this question.  For Cluster Housing applications in the Placitas Area, the only two applicable bits of county legislation are to be found in the Placitas Area Plan (PAP) and the SCZO:

 “Developers should be allowed to cluster housing units on a smaller single family lot size. A cluster development should be allowed to cluster on 50% of the total predevelopment parcel. However, undevelopable area such as slopes greater than 40% as well as arroyos should not be considered as part of the gross parcel.” (PAP, page 64) (emphasis added)

“Although, an SU district for a clustered housing development may be authorized only if the total number of dwelling units in that development does not exceed that which would have been allowed if the site were developed under its previous zoning designation.” [SCZO 10(D)(3b)] (emphasis added)

On October 10, 2008, the PZC conducted a workshop aimed at developing language on cluster housing in both the PAP and SCZO.  I wrote a discussion brief for that workshop, and distributed copies at that meeting.  My brief outlined the need for definition of “building areas”, set-backs, minimum lot sizes, etc.  County staff had assured citizens that though full specificity regarding these would not appear in the PAP, they would be included in the zoning ordinance revisions that followed.  But that was not the case.  The PZC Chair announced at that meeting that instead these specifics would be considered on a case-by-case basis for each application for cluster housing zoning.  As a result only the above very vague wording appeared in the PAP and SCZO.

The lack of definition of undevelopable area in PAP and SCZO does not relieve an applicant for cluster housing SU zoning from the obligation of addressing this in the application, since both PAP and SCZO require that this determine the maximum number of housing units.  As the Cashwell application does not adequately address this issue, it is therefore incomplete.  In the following I will recommend ways in which this issue can be addressed, both by the applicant and by County Staff and Commissions.

It should be noted that the description of “undevelopable area” in the PAP uses a totally skewed example: “slopes greater than 40%”.  Obviously slopes greater than 40% are unbuildable, but in the same way that 600 mph is an unsafe speed for I-25.  So is 200 mph, or even 100 mph.  I can only speculate how this 40% figure was chosen for this example in the PAP.  Perhaps it was pulled from my previously mentioned brief, which among other examples cited that of Asheville, North Carolina, which then allowed development on up to 40% slopes, but only if the maximum housing zoning density was reduced by 90%!  Asheville has since modified their ordinance to prohibit development on slopes greater than 25%[1].

Due to the lack of adequate specifics in county law, legitimate determination of maximum number of clustered housing units on a property must be based primarily upon interpretation of the term “undevelopable” in the PAP and the phrase “would have been allowed if the site were developed under its previous zoning designation” in the SCZO.  Interpretation of this language must properly be guided by two considerations: 1) What adequately preserves the character of the area in which the property is located; and 2) What is reasonably considered developable by other regions with similar characteristics.

Attention to the first of these considerations is mandated in both the PAP, for properties in the Placitas Area, and just as emphatically in the SCZO for the county as a whole.  A primary goal identified in the PAP is “maintaining the semi-rural landscape and existing development patterns” of the Placitas Area.  As to the second consideration, because cluster housing does not yet exist to any significant extent in the unincorporated parts of Sandoval County, some guidance ought to be sought outside the county for what is and is not buildable.

One obvious feature of an area’s character is the general density of housing units.  When considering the application for Cluster Housing re-zoning on the Cashwell property, a prominent factor must therefore be the density found in adjoining and nearby developed areas.  One can map a square mile that includes the “S Curve” on NM165, which is located one mile north of NM165, and which for the most part is “built out”.  It contains about 100 homes.  The terrain within this square mile (640 acres) of existing development is far less severe than that of the Cashwell property.  Its density of one home per 6.4 acres is therefore representative of this aspect of the character of the area.  Clearly the application to build 65 cluster homes on 87 acres on the Cashwell property, meaning one home per 1.3 acres, would produce a development that is far more dense.  Cluster housing developments will by definition include some areas that have higher density than under standard residential zoning.  But the property as a whole, including “open space” areas, should not so greatly exceed the housing unit density of the general area, if that area’s character is to be preserved.  The Staff Report on the Cashwell application suggests that the density is acceptable here, because standard zoning for the West Placitas Community District, where the Cashwell property is located, sets the minimum residential lot size as 1 acre, which in the abstract would allow for 87 such lots on the Cashwell property.  But given the average density in the area, this in fact would not preserve “existing development patterns”.

The existing development patterns in the Placitas Area, as indicated by the sparse density of housing units, is largely due to the terrain attributes in the region.  It must be noted that the terrain on the Cashwell property is among the most challenging in Placitas.  In general, the following terrain attributes of the Placitas Area have dictated the sparse densities due to risks of negative return on investment and/or unacceptable liability:

• Building in water courses and small set-backs from them.  These areas are now defined by FEMA as flood plains, which makes this land effectively unbuildable.
• Building upon Placitas Area soil types and steep slopes.  Placitas soils liquefy easily and erosion occurs rapidly with soil saturation.  Liquefaction can occur more easily by the disturbance and de-consolidation of soil.  Hard surfaces like roofs and drives increase soil saturation surrounding structures.
• Most soils in the Placitas Area liquefy and flow rapidly when saturated and if on slopes greater than 10%.
• Most homes in the Placitas area are built on slopes of less than 10%, as well as most drive ways and other functional areas surrounding homes.
• Erosion control becomes almost impossible upon slopes greater than 20%.  For example, to prevent erosion of property, most Placitas developments incorporate detention ponds.  A small ten foot diameter detention pond that is two feet deep and with a weir one foot below rim on a 30% slope has a face on the downhill side of four feet plus!  Without a hardened face such as concrete, this pond will fail and take with it the slope it was to protect and including that upon which a home may be bearing.

Considering SCZO 10(D)(3b) (quoted above), if these and related factors were applied to a subdivision plan for the 87 acre Cashwell property, which has a good deal of slope greater than 20%, a number of arroyos, and soil conditions at least as challenging as in other parts of Placitas, it is unlikely that any more than 30 to 35 acres would be considered properly developable, which under present zoning would allow for that same number of homes.  And, this does not take into account that this would still be significantly more dense than the one home per 6.5 acres in the surrounding area.

Given that cluster housing is essentially new in unincorporated Sandoval County, the county must look for guidance from other sources, such as the zoning ordinances in other communities.  Slope is a major driver in the definition of what is undevelopable, and guidelines set down by both official and non-official professional organizations are available.  The following and the previously mentioned Ashville ordinance, are samples of these sources focused on what is allowable where steep slopes are present:

• DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT – Does not define maximum slope, but does require a site analysis test for buildable areas having slopes greater than 10%.
• Missoula, MT –  Defines buildable areas as 25% or less slope.  Note:  Building in this area usually required removal of bedrock.
• Smart Communities (www.smartcommunities.ncat.org) –  For a slope of 25 percent or greater, 80 percent must remain as open space with no more than 20 percent being altered or developed.
• Carmel, CA –  Determining Buildable Area: For the purposes of calculating allowable building volume and floor area, the buildable area of a lot shall be the lot area, minus continuous portions of the site, occupying at least 10 percent of the site area, with a slope greater than 30 percent.
• Harrison, NJ – Buildings may be constructed in accordance with the regulations of the applicable zoning district except that the minimum lot area shall not be less than two acres, and provided that no portion of the building is constructed on a slope where the grade exceeds 20%.
• State of New Jersey’s Water Quality Management Planning rule (N.J.A.C. 7:15)  — The applicant shall demonstrate through site plans depicting proposed development and topography that new disturbance is not located in areas with a 20 percent or greater slope.  [Municipalities may include additional restrictions for 20 percent slopes or include restrictions for lesser slopes, at their discretion, as long as the minimum requirements above are met.]
• 10 Towns Watershed Committee as a prototype for adoption by its municipal government members. — On slopes of 25% or greater, no development, re-grading or stripping of vegetation shall be permitted. Any disturbance for roadway crossings or utility construction in areas of 25% slopes or greater are considered variance conditions and the applicant must affirmatively demonstrate that the roadway or utility improvements are necessary in the sloped area. The sloped area to be developed, re-graded or stripped of vegetation shall be drawn on the development plans for each individual lot.
• Lehigh Valley Planning Commission –15% to 25% slopes are only suitable for low-density residential, limited agricultural and recreational uses. Over 25% Only used for open space and certain recreational uses.
• Cranbury Township Ordinance # 03-11-07: AN ORDINANCE REGULATING THE INTENSITY OF USE IN AREAS OF STEEPLY SLOPING TERRAIN TO LIMIT SOIL LOSS, EROSION, EXCESSIVE STORMWATER RUNOFF, THE DEGRADATION OF SURFACE WATER AND TO MAINTAIN THE NATURAL TOPOGRAPHY AND DRAINAGE PATTERNS OF LAND.  — The applicant shall demonstrate through site plans depicting proposed development and topography that new disturbance is not located in areas with a 20 percent or greater slope.
• Shenandoah, VA; – Prohibits construction on slopes greater than 20 percent and replaces  the previous ordinance that allowed building on lots with slopes of up to 40 percent with a special use permit (SUP).
• Van Buren County – (2) No site disturbance shall be allowed on slopes exceeding twenty-five (25%) percent
• Chimney Rock Village  – As the definition of steep slope indicates, any proposed development whose average natural slope is less than 15% is not subject to the regulations for permitted density as set forth herein.  Any proposed development which meets the definition of steep slope and whose average natural slope is above 30% is subject to the most restrictive site density.
  • (A) 15.0% to 19.9% slope: 1 dwelling unit per 3 acres.
  • (B) 20.0% to 24.9% slope: 1 dwelling unit per 5 acres.
  • (C) 25.0% to 29.9% slope: 1 dwelling unit per 7.5 acres.
  • (D) 30.0% slope and greater: 1 dwelling unit per 10 acres.

Summarizing the provisions of the thirteen above samples reveal that all impose restricted use on “steep slopes”; one imposes additional conditions for slopes greater than 10%; three impose additional conditions for slopes greater than 15%; seven or 54% impose additional conditions for slopes greater than 20%; two following implementation of their original slope ordinances later revised them to more restrictively make slopes greater than 25% non-buildable, and do not allow even soil disturbance on slopes greater than 25%.

These significant facts cannot be ignored:

1)      Twelve or 92% impose additional conditions for slopes greater than 25%.

2)      All thirteen impose additional conditions for slopes greater than 30%.

3)      All thirteen either completely disallow or reduce “buildable” areas by 80 to 90% within areas defined as steep slopes.

CONCLUSION:

It would be prudent for Sandoval County to adopt a steep slope ordinance that may need to vary for certain areas.  Soil types vary within the county and consequently so does the natural angle of repose of slopes.  Santa Fe County has a 30% maximum slope for development, but its soil types are far more stable than those found in Placitas and around Rio Rancho, although the soils found in the Jemez may be similar to those in Santa Fe County.

Maximum buildable slopes within the Placitas area should not exceed 20% without significant restrictions, and possibly, due to our unstable soil types, not exceed 15%.  A simple observation and sampling of existing developments within the Placitas area could determine the predominate voluntary limits of buildable areas.  Statistical analysis of the sample set would then conclusively define the market driven maximum slope, and would provide solid foundation for the implementation of PAP goals, particularly “maintaining the semi-rural landscape and existing development patterns” of the Placitas Area.  This in turn would work towards providing a usable definition of the crucial term “undevelopable”.  The housing unit calculation necessary for Cluster SU applications would then become a mathematical solution, as it should be.

Safety Illustration:

Slope failures may be triggered by construction practices. Development on slopes commonly requires construction of a flat site on which to put a house. With the cut-and-fill technique, material is removed from the uphill part of the site and placed on the downhill portion to form a level surface. The fill material may compact and settle later, and cause cracking of foundations and walls. The extra load of a building may trigger a slope failure on unrestrained fill. Retention walls and pre-compaction of fill may lessen the potential for that type of slope failure. Construction excavation may over-steepen slopes, increasing the chance for slope failure. Fill material may settle, causing cracking in buildings.