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KPVillas.org
KPVA Retention Pond
KPVillas has multiple common areas that are owned and maintained by the homeowners association, including the parcel containing the KPVA retention pond that collects neighborhood storm water. Three pond issues merit attention:
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Spillway
On the south side of the KPVillas retention pond is a degraded spillway. When the pond fills during a heavy rain, the excess water flows south over the rim of the pond and across a rock-lined spillway into the St. Joseph County (SJC) retention basin. Over time that spillway has degraded, and the drop-off from the KPVillas pond to the SJC basin is encroaching northward across KPVillas property. See more about Spillway below, including August 2023 County proposal to expand its basin north and east. As an interim solution, the eroding berm was buttressed by excess river rock being removed from a nearby property. -
Invasives
The landscaping around the KPVillas retention pond has deteriorated, unlike other common areas required to be maintained by the HOA, with invasive and nuisance plants dominating the area. Honeysuckle and some other invasives have been removed by volunteer KPVillas homeowners, as detailed in blog posts tagged "pond". In late 2024, invasive yellow flag iris dominating the perimeter of the KPVA retention pond has been treated with a first application of herbicide specified for water environments. Part of the south berm and the east landscaping bed have been weeded and seeded. Volunteer restoration efforts are ongoing. -
Retaining Walls
The original wooden KPVA retaining walls are candidates for replacement. Because they are on the parcel owned by KPVA, it is the Association's responsibility to address. In 2024 the KPVA Board began soliciting bids for replacing the walls.
Maintenance of the common areas remains a KPVA responsibility. Per Section 15 of the KPVA Covenants, "The Association shall provide maintenance, replacement and repair services for all Common Areas and all improvements to the Common Areas. Such expense shall be a Common Expense."
Note: KPVillas.org is not the official website of any HOA or Board. See disclaimer below.
Invasive Species
Per the Indiana Invasive Species Council:
Exotic invasive species are non-native plants, animals or microbes that spread aggressively, replacing native organisms and posing serious threats to human health and well-being, the environment, or our economy.
Identification
A 2022 map shows the inventory of plants that were around the KPVillas retention pond then. Homeowner volunteers removed most of the dominant invasives. An ensuing survey by a regional specialist from the State of Indiana Cooperative Invasives Management (SICIM) yielded a 2024 invasive species management plan.
Removal
The SICIM management plan suggests techniques and timetables to eradicate the invasive species, including manually, cut surface, and foliar spray. Among the aggressive plants prioritized for removal in 2025 are the yellow flag irises.
Restoration
After removal, remnants of the removed invasives can return. A common practice is to introduce landscape alternatives that fill in where the invasive plants previously dominated. Plants that were cut at the stem may have shoots that need follow-up treatment in ensuing years, too. The Midwest Invasive Plant Network offers solutions. Part of the south berm and the east landscaping bed have been weeded and seeded.
"Asian bush honeysuckles grow so densely they shade out everything on the forest floor, often leaving nothing but bare soil. This means a great reduction in the food and cover available for birds and other animals. Serious infestations can inhibit tree regeneration, essentially stopping forest succession. Some bush honeysuckle species also release chemicals into the soil to inhibit other plant growth, effectively poisoning the soil."
Pond Spillway
The KPVillas retention pond receives stormwater runoff from much of the neighborhood. When the pond fills, excess water is supposed to flow over a gap in the pond ridge and across an existing spillway into the larger St. Joseph County retention basin to the south.
That spillway is deteriorating, and the County basin has issues that may be resolved by the County's expanding the size of the extant basin to the north and east. As SJC has a shortage of drainage funds, river rock across the KPVA berm is an interim solution.
Shortcomings
A January 2021 Storm Water Drainage Study details shortcomings in the existing drainage scheme. KPVillas blog posts tagged "pond" describe additional issues.
Over time, excess water overflowing the back side of the pond has eroded the spillway. The drop-off from the KPVillas retention pond to the SJC retention basin is encroaching northward across KPVillas property.
In 2023 St. Joseph County (SJC) engineers proposed tiered modifications to its retention basin south of KPVillas "to allow the basin to completely drain after storm events," per SJC engineers' meeting minutes. Regardless of the eventual basin changes, the next phase of the plan will likely include re-construction of the degraded spillway between the KPVillas pond and the SJC basin, for which the County will take the lead role. Design options for the spillover include "geoweb, a culvert, and riprap."
If initial conservative efforts by SJC don't improve the basin's water-removing capability, more aggressive options would follow. Then, outcomes of new construction may include, but are not limited to, dewatering the basin; an expanded basin to the north and east; loss of foliage along the boundary; and a longer and closer fence along KPVillas lot lines.
Stormwater overflows KPVA pond.
County Action: 2023 August
St. Joseph County (SJC) has identified some next steps in the Gumwood Road Basin Improvements project, which is a County initiative to alter the large retention basin on the south boundary of KPVillas. Per the minutes of a 2023 August 15 SJC Design Meeting, the County seeks "to allow the basin to completely drain after storm events." Among design outcomes may be dewatering the basin; an expanded basin to the north and east; loss of foliage along border; and a longer, closer fence along KPVillas lot lines.
The County basin was originally supposed to hold excess stormwater until the water percolated through the ground. Instead, it has retained water continuously, with the excess water encroaching on adjoining private properties after heavy rainfall. Recently the County commissioned a study from engineering firm Lawson-Fisher Associates PC (LFA), after which the County staff met with LFA to discuss remediation and next steps.
A former KPVillas homeowner recalled how he was told by a party to the original basin construction, "You'll never see water in there." In fact, the homeowner never saw it dry, for the basin has always held water like a pond. Over time the basin with its omnipresent water has become a vibrant habitat for waterfowl.
In the meeting minutes, the geotechnical report notes how an impermeable layer of silt is preventing groundwater from filtering down to the water table. "Currently there is a layer of fines on the surface of the basin floor that is preventing drainage, which must be addressed before any solution is implemented."
The County will likely take a tiered approach to improve the functionality of the existing basin. If one conservative modification doesn't work, it would step up to a more ambitious (and expensive) plan. A possible first step is to de-water the pond and locate the sandy levels indicated by the studies. Capital improvements would begin with drywells if they're deemed a viable solution. These large concrete cylinders with holes would punch through the impermeable layer and allow accumulated water to percolate down.
If alterations within the extant fence line don't yield a sufficiently lower water levels SJC would consider a more aggressive project. For example, a leading County proposal would be to purchase the (Fox) farmland east of the County's current retention basin and to expand the basin's size. That plan may include expanding north and east, potentially bringing the County basin and its longer fence up to the property line of KPVillas.
Another design item from the engineers' meeting specifically addresses the KPVillas pond and spillover. A construction supervisor writes, "We did discuss the transition area between ponds, and the reconstruction of that area is also included in the next phase." From the meeting minutes:
Riprap Overflow from Knollwood Villas Basin – The landowners to the north of the project have requested that the project allow them to continue to utilize a walkway around the edge of the pond to the north of the basin. To mitigate future erosion, options will be reviewed for the overflow that passes into the basin. Examples given were geoweb, a culvert, and riprap. A culvert would be least desirable due to the potential for backwater from the Gumwood Basin to impact the Knollwood Villas Basin.
Expensive caissons had been considered for the site; however, "acquiring property, expanding the basin to the east, and installing drywells would likely eliminate the need for extensive dewatering."
The County's 2023 August meeting minutes conclude with Next Steps:
Final Plans and Specifications –
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LFA will provide an exhibit that identifies the area to be acquired in order to expand the basin per the recommendation from the 2020 report.
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LFA will design a typical section of the area north of the basin to serve as an emergency overflow from Knollwood Villas. Considerations for it being traversable by pedestrians will be incorporated.
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LFA will gather pricing estimates for different construction alternatives in order to compare them to the cost of acquiring the Fox property to the east.
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The City (sic) will investigate the cost and feasibility of purchasing the Fox property.
Above:
Figure by Lawson-Fisher Associates PC shows proposed County basin expansion and property acquisition. (PDF)
Right:
Properties abut KPVillas retention pond or SJC basin.
Below:
Spillover allows stormwater to overflow KPVA retention pond and cross boundary into County basin.
Blog Posts
Existing blog posts tagged "pond"...
Disclaimer:
KPVillas.org is an independent website that does not represent the opinions or initiative of any HOA or Board. An official HOA site is at KnollwoodParkVillas.org.