PUBLIC HEARING: Consider Ordinance #19-03 Amending the Definition of Topsoil (Project No. 18-146)

In the mid-to-late 2000s, the City adopted a new development requirement, requiring all new construction to establish 4" of premium topsoil. The intent was to reduce the consumption of water related to lawn irrigation. Through several appropriations request to the Minnesota Department of Natural Resources for additional public wells, the City needed to implement additional water conservation measures due to the high consumption compared to peer communities. A large portion of this consumption was due to lawn irrigation in very sandy soils. While the current standard is quite effective in water conservation, Staff believes it is an appropriate time to evaluate the cost-benefit ratio. The standard has not reduced the amount of development in the community, but the City has received much feedback on the standard.

For several years now, the City has been receiving feedback on the current topsoil requirement, both in the field and at other forums such as the Contractor's Networking event, hosted by the City.  More recently, the City received a written request from Capstone Homes to consider revising the topsoil standard by eliminating the specification for Premium Topsoil Borrow (a now former MnDOT specification).  The request identified two negative effects of the current topsoil requirement. First, that the topsoil is doing too good of a job in terms of holding water. They acknowledge that many homeowners are likely not adjusting their irrigation systems to account for the topsoil and are actually contributing to the problem. Secondly, they identified price as a concern compared to the cost of 'regular' black dirt.

Staff has had multiple discussions with the EPB regarding this topic.  The EPB requested Staff to gather information on what similar peer communities (with similar sandy soils) require and what the purpose of the requirement was (to see if it is an apples to apples comparison).  Staff looked at the requirements for communities such as Andover, Big Lake, and Blaine, all of which have a topsoil requirement and are growing communities on sandy soils (Elk River was also contacted but due to significant opposition, they did not adopt a topsoil requirement and rather, through their municipal utilities division, implemented a rebate program focused on improving irrigation systems).   

A Notice of Public Hearing was published in the Anoka County UnionHerald.

Review of Peer Communities Topsoil Requirements

Staff contacted multiple communities that are all situated within the Anoka Sand Plain (these would, in general terms, all have sandy 'base' or native soils with less water holding capabilities).  A summary of each communities' standards is attached to this case.  Based on this review, it is clear that Ramsey has a much more stringent approach to topsoil, from how it is defined to our inspection process, than other communities.  It seems that communities that have adopted a topsoil requirement have done so with an intention of reducing demand on groundwater while also assisting with vegetation establishment.

Cost Comparison

Staff has also obtained cost estimates from the builder/developer making the request and others regarding the cost of topsoil meeting the City's current specification and standard pulverized black dirt.  The information helps illustrate the cost added to an individual lot (and therefore, passed on to the home buyer) to comply with this standard.  As a reminder, the topsoil requirement is applicable to any lot (commercial/residential/industrial/institutional) being developed with a new, principal building, regardless of whether it is connected to the municipal water system or not.  These costs are representative of the typical residential lot sizes being developed currently.
 

Approximate Lot Size	Estimated Cost of Premium Topsoil Borrow	Estimated Cost of Regular Black Dirt	Price Difference
6,000 sq. ft. (0.15 acres)	$3,690	$2,250	$1,440
10,800 sq. ft. (0.25 acres)	$5,740	$3,500	$2,240
43,560 sq. ft. (1 acre)	$10,660	$6,500	$4,160
108,900 sq. ft. (2.5 acres)	$19,000	Unknown	Unknown

Alternatives to Premium Topsoil Specification

As has been noted, the present request is not to entirely eliminate the topsoil requirement, but rather to modify it to something more consistent with surrounding communities.  This would still provide improved soil characteristics (compared to the native/base soil), but at a more cost effective rate.  This could also help eliminate some of the undesirable characteristics that many yards have exhibited, such as oversaturated, spongy/soggy ground (which is also a result of over watering, not just simply due to the topsoil).

Advances in irrigation technology over the past decade have made it easier and more cost effective to conserve water through better sprinkling habits.  Smart controllers can be connected via the internet to local weather information, weather stations, historical precipitation data, etc. to assist with reducing unnecessary waterings.  Also, soil moisture sensors, often available for $150 or less, can be utilized in different parts of a yard (with different growing conditions) to ensure that the irrigation system doesn't turn on that zone unless there is insufficient moisture in the soil.  The message coming out of the University of Minnesota's Extension team is that water efficient irrigation systems, not new turf varieties or soil amendments (topsoil), have become the most cost effective means to reducing non-consumptive water usage (e.g. irrigation).

City Code now requires any new irrigation system to have a water efficient technology.  However, there are many systems out there that could be retrofitted.  This comes at a higher cost than 'upgrading' a new system.  The City could consider developing a rebate program that may incentivize owners of older irrigation systems to retrofit them with newer irrigation technologies, as a future discussion.  Additionally, a simple 'irrigation system tune-up' could also be incentivized to not only ensure that a system is running properly with no leaks or malfunctioning parts, but also, hopefully, educate homeowners about how their system works, and allow adjustments to systems that were never dialed back after the lawn was initially established (new systems are typically set to water new lawns heavily on a daily basis).  The City of Elk River, through their municipal utilities division, has an established rebate program that could be used as a model.  It may also be possible to find grant funds that could be utilized to establish and offer these rebate programs.

Weather/Precipitation/Landscape

The largest factor in water usage has always been and will likely always be the weather, and more specifically, precipitation.  That's one of the greatest advantages of the new technologies now available for irrigation systems, weather can be and is factored into the programed run-times.  The water usage data from the City does show a clear correlation between reduced precipitation and increased water usage. 

Additionally, canopy cover can also play a significant role in watering needs of a yard.  Shady portions of a lawn require much less water than sunny portions.  Again, options such as soil moisture sensors placed in differing growing conditions within a yard, can significantly reduce water usage by restricting which zones actually run on a scheduled day/time.

Recommendation

While topsoil is a beneficial addition, both for water conservation and vegetation establishment, the cost difference of an engineered soil compared to a more standard black dirt is significant.  Focusing more on irrigation systems and water efficient technologies rather than engineered soils, along with additional public education on the use of irrigation systems, will be more effective than the current premium topsoil requirement for reducing demand on groundwater.  It would also be accomplished at a lower cost to the future homeowner (and possibly current homeowners if a rebate program were implemented).

The EPB has reviewed this topic and did recommend proceeding with an Ordinance to amend the definition of topsoil to be more similar to surrounding peer communities.

Alternatives

Alternative 1: Recommend adoption of Ordinance #19-03 to amend the definition of topsoil to be more consistent with peer communities.  Staff has seen examples of yards that are oversaturated, either from on-site irrigation, neighboring irrigation, and even from multiple days of precipitation, resulting in spongy, unusable areas.  Continued advancements in irrigation system technologies, along with development of enhanced educational materials on irrigation system operation and maintenance, should result in less demand on groundwater for irrigation purposes at a lower cost to future homeowners.  The EPB and City Staff support this alternative.
 
Alternative 2: Recommend the City Council not amend the current definition of topsoil and continue to require an engineered soil for all new development.  Based on the cost of this engineered material, and the advances in irrigation technology (as well as continued research and development of grasses such as fine fescues that are more drought tolerant and require less water inputs), Staff does not support this alternative.

This case is being handled as part of Staff's regular duties.

Motion to recommend City Council adopt Ordinance #19-03 amending the definition of topsoil.