Stormwater Management

By Skip Sly and Bill Adamsen

What is stormwater runoff?

During and after a storm, water that falls on forest or other permeable soils can infiltrate down into the ground and eventually into the groundwater. Water that falls on impervious surfaces, such as roads, parking lots, even compacted lawns — cannot soak into the ground, and instead moves across these surfaces. As the water leaves the impervious surface it has more volume (less has been retained in the soil) is moving faster over the ground, and picks up more sediment carrying phosphorus, fertilizers and even chemicals such as pesticides. This is added to the oils and salts that had been deposited on roads and became dissolved or suspended in the stormwater. Together these dissolved and suspended pollutants are now deposited into the Lake. Development typically converts permeable soils to soils that are impervious. Though there are ways to reverse the impacts and thus effects of that trend.

Primary productivity by phytoplankton (including cyanobacteria) is usually limited by the availability of Total Phosphorus (TP) in reservoir ecosystems. The amount of phosphorus in reservoir water is the result of P loading from the watershed, direct atmospheric deposition, and internal loading from bottom sediments. A number of simple empirical models can estimate external and internal phosphorus loads, and forecast reservoir productivity, from observed Spring TP and core incubation. Although TP availability often controls the amount, or rate, of primary productivity, other ecological factors tend to dictate what types of organisms perform the primary productivity: Macrophytes, Phytoplanktonic Algae, or Cyanobacteria. Although phosphorus availability usually limits overall productivity in freshwater ecosystems, other factors can become limiting to primary producers at times including nitrogen, inorganic carbon, light (intensity and wavelength), and silica.

from Cyanobacteria in Reservoirs: Causes, Consequences, Controls by Robert Kortman PhD. New England Water Works Association June 2015

full paper

What are the effects of stormwater runoff?

The suspended sediments can cloud water, affecting plants, fish, and other aquatic life; before eventually settling to the bottom. There they reduce water depth, provide a footing for growth of aquatic plants, and destroy native fish habitat. The excess nutrients carried into the water (phosphorus from sediments and nitrogen from chemicals, fertilizer and organic matter) can cause increases in algal growth. Bacteria and pathogens from septic systems or surface wastes can make water unsafe for drinking and swimming and impair aesthetics. Road salts from the winter increases chloride levels in the lake. Some of these pollutants will never leave the lake while others, due to the specific nature of West Hill Pond — will take a very long time to disappear. The ultimate impact could be a loss in lake water quality and recreational use – and subsequently the value of West Hill Pond properties, camps, and parks.

• Stormwater Sampling

  Water bottles – spring water bottles — will suffice. Rinse with the water you’re collecting three times then fill and close the lid tight. Keep the samples in a cooler with ice packs. You’ll be putting these samples in the freezer when you return home, and we’ll organize collection by the limnologist during the monthly visit.

  Get some white medical tape and wrap tape around the bottle and use a Waterproof Sharpie to write the info on the label.

  You can collect water from the inlets at any time but just record time and date and site on all bottles.

  The sites can be names you find suitable that you can use for the site from then on. Like Pete’s Culvert, Keep a log of what you do and what you see. For example if the Pete’s Culvert is in the middle of Lake Road – record this in the log if you have house numbers even better. Also keep notes of what the water flow is like – is it roaring or just a little more than usual. Also was it brown or clear or both or what?

  Label needs:
  West Hill Pond
  [Date] – [Time]
  location [eg “End of lake drive”]
  [GPS Waypoint] if you have gps than record a waypoint number.

  It also doesn’t matter where you go. There are numerous hot spots all around the lake, ideally pick an inlet from the watershed study and indicate that inlet number on the bottle. Simply drive around in the rain and look for flowing water (storm flows) Write down where you are what you see and get a sample. And if you want to what the whole storm than keep checking on sites as the storm waxes and wanes because water flow will be different.

What is the impact on West Hill Pond?

West Hill has a surface area of 261 acres and a watershed area of roughly three-times that, or 790 acres. Compared to other CT Lakes, the West Hill Pond watershed is relatively small related to the area and volume of the lake. The runoff from this watershed replaces or flushes the lake about once every four to five years. Any dissolved materials conveyed to the lake from the storm water systems tend to have a long residence time which is the major contributor to the long-term degradation of the lake. Of course any suspended materials tend to settle in the lake and remain there forever.

(click image to enlarge)

West Hill Pond – Stormwater Management Survey and Report

In June of 2011 a Storm Water Runoff Survey was completed and Report compiled, identifying 15 major inflow channels, the drainage acreage of each, and establishing a priority for the installation of upgrades to those drainage locations. Some limited progress has been made towards addressing the recommendations of the Survey. In the image at left (click image to enlarge) the shaded yellow areas represents watersheds which drain into the lake via major inflows. The shaded red area indicates areas that drain into the lake without major inflows. The numbers represent the major inflows with further information listed below by priority.

West Hill Pond – List of Watershed Stormwater Inflows

A number of the inflows have had recent engineering and are being actively managed. Others are awaiting engineering and the resources to address. This list of prioritization is adapted from the Lenard Engineering report referenced above.

• Survey Recommended Actions Update (prioritized)

  

  Inflow 14 — Upper LAPOA (Rickie, Davis, Dorothy Harriet Roads) — Priority #1 — The Town of New Hartford has submitted a grant request to the State for $15,000 to install 4 new catch basins in this area as recommended in the Survey. Approval is expected shortly. Also the drainage channel below Ricky Rd has been cleared of debris as recommend to eliminate further erosion. This was done at the property owners own expense.
  
  (click images to enlarge)

  

  
  Inflow 7 — West Hill Road West of Niles — Priority #2 — Roadside drainage through a Catch Basin into a wetland area on south side of West Hill Rd and then culverted under the road to an open drainage to pond. The town of New Hartford has submitted a grant request for the reconstruction of the road including improved catch basins as recommended in the Survey. The request is still pending.

  

  Inflow 6 — West Hill Road — Priority #3 — The town of New Hartford has submitted a grant request for the reconstruction of the road including improved catch basins as recommended in the Survey. The request is still pending.

  

  Inflow 10 & 11 — Marstan Trails — Priority #4, #7 — Some engineering work has been done in conjunction with other work a home owner is doing to control excessive runoff going across his property.

  

  Inflow 12 — Pond Road — Priority #5 — Cost estimates for the surveying work and engineering plans needed to obtain the permits necessary to move forward with construction are being obtained. Preliminary estimates for those costs are in the range of 8 to 12 thousand dollars.

  

  Inflow 1 — LAPOA Beach — Priority #6 — Requires engineering and mitigation to prevent the erosion of sand and silt into the pond. No action currently underway.

  

  Inflow 9 — Niles Road — Priority #8 — There are currently nine catch basins along Niles Road with significant volumes of inflow to the lake. The town of New Hartford has submitted a grant request for the reconstruction of the road including improved catch basins as recommended in the Survey. The request is still pending.

  

  Inflow 8 — Brodie Park Beach — Priority #9 — The Town of New Hartford has installed silt fence during the winter to control beach erosion and will use coarser sand for future beach replenishments.

  

  Inflow 3 — Camp Workcoeman Road Parking Runoff — Priority #10 — Significant engineering and construction work was completed in this area over the past few years to mitigate issues associated with stormwater. Monitoring and management of the identified work needs to be scheduled or reviewed.

  

  Inflow 15 — Aquatic Road — Priority #11 — Engineering plans are being finalized. Once completed they will be submitted to Inland Wetlands for approval.

  

  Inflow 13 — Niles Road (Pond, Beach, Harriet Roads) — Priority #12 — This area requires engineering for the regrading of road and installation of Catch Basin’s per report. None of this work has been engaged.

  

  Inflow 4 — Camp Workcoeman Road Brook — Priority n/a — Significant engineering and construction work was completed in this area over the past few years to mitigate issues associated with stormwater. While not currently an area of concern, with a watershed drainage of over 150 acres (20% of total), this area should be monitored for effectiveness of the mitigation, and should be maintained in order to ensure that the various engineering structures are functioning effectively.

  

  Inflow 2 — Camp Workcoeman — Priority n/a — Draining a significant 53 acres, this stream turns to a torrent during storm events. The stream channel need to be kept clear of debris and monitoring needs to ensure the road crossing does not overtop during storm events. Monitoring and management of the stream needs to be scheduled.

  

  Inflow 5 — Camp Workcoeman Road near Sequassen — Priority n/a — Significant engineering and construction work was completed in this area over the past few years to mitigate issues associated with stormwater. Review to identify how to comply with the recommendations of the report need to be scheduled.

Stormwater and the Watershed Homeowner

While these 15 inflow channels drain a significant acreage of the total watershed (400.2 acres – 50.7% combined) and the lake itself represents about 1/3 of the watershed (261 acres), there is still significant area (129 acres – 16.3%) with no appreciable channels but an important contribution of stormwater. On the map in the image to left (click image to enlarge) the shaded red areas represents areas that drain into the lake without major inflows mostly through the waterfront properties.

As mentioned earlier, development reduces the amount of permeable soils available to retain stormwater. The wooded areas of Camp Sequassen, Camp Workcoeman and Brodie Park may contribute very little to lake degradation. What does contribute to degradation however are the developed properties along the shoreline. Here it up to the homeowner to do all he or she can to keep storm water on the property for as long as possible and assure that when the water ultimately reaches the lake it is as clear of debris as possible. So there are strategies to reverse the impacts of development. These are so called Best Management Practices.

Here are a few best management practices you could research further to minimize your properties contributions to stormwater runoff.

• Rain Barrels
• Dry wells
• Drainage Swales
• Riparian Buffers (a vegetated planting strip along the shoreline)
• Restoration of native plantings
• Rain Gardens
• Pervious pavement choices
• Proper location of impervious surfaces and reduction where feasible
• Where lawns exist, limit or eliminate fertilizer

We’re collecting links to various resources in the section below on Homeowner Best Management Practices you can refer to for more education. But also reach out to me directly and I can refer you to landscape professionals and local residents that can share information on how you can become a stakeholder in implementation of best management practices for your property.

Resources for Stormwater Reference and Best Practices

• Lake Watershed Management Plans

  • lake protection ordinances article
  • Columbia Lake Watershed Management Plan
  • Staffordville Lake and Watershed Update
  • A Stormwater Management Planning Guide
  • Lake George (NY) Guide to Stormwater
  • Water Testing Rationale (2015)

• Water Quality Resources

  • CT DEEP Lake Water Quality Programs

• Homeowner Best Management Practices

  There are lots of resources on ways to retain stormwater. There are subsurface retention structures (drywells) and surface gardens which can replace lawns (low retention structures) and also collect rain from roofs or driveways. There is also a fair amount of research going into permeable driveways. All of these can and should be considered either with new development plans, or as upgrades to existing developed properties.

  • State of Connecticut Raingarden Guide for Homeowners
  • Good Buffer Species – from the Northwest Conservation District [1.7mb]
  • First Light (Candlewood Lake) Shoreline Management manual [11mb]
  • The UConn Sustainable Landscapes Page
  • State of CT Stormwater Management Guide for Homeowners
  • Technical Article on how rain-gardens work
  • Center for Watershed Protection great ideas for using stormwater productively and reducing deleterious effects of stormwater
  • UConn Nemo Guide to TMDL
  • UConn Guide to Permeable Pavers
  • UConn – Permeable Paver Implementation Projects

The Watershed and Zoning

Zoning Map Overlay The section of West Hill Pond’s watershed which falls within the Town of Barkhamsted is regulated by the R2A Zoning Regulations of the Town of Barkhamsted. The section of West Hill Pond’s watershed which falls within the Town of New Hartford is regulated either by the Town of New hartford R2 or R4 Zoning Regulations. For a larger map – not official – but which details the relationship of the watershed and zones click here [2.2 mb filesize].

Where does the Water Go?

West Hill Pond has a single outflow through the dam structure on the north end of the lake. The lake is the headwater of the Morgan Brook which flows through New Hartford towards its confluence with Mallory Brook and eventual confluence with the Farmington River. Morgan Brook has been the subject of studies by the Northwest Conservation District, DEEP and the USEPA. Their report can be found here.