Brookstone Sump Pump Project

Homeowners commonly use sump pumps in their basements to battle water and flooding issues. Most every house has a sump pump installed for the purpose of discharging clear waters from foundation drains and ground infiltration. Sump pump water is what engineers call "clear water" and most often is rain water, ground water, or snow melt. This water should flow directly into area streams, ponds, and lakes. Where the building is not serviced by a storm sewer, the discharge from a sump pump should be put into an underground conduit leading to a drainage ditch, dry well, or discharge onto the ground surface in such a manner as will not constitute a nuisance.
The reason sump pump piping is not installed during platting in low to medium density developments is to reduce the amount of directly connected stormwater runoff. Minimized Directly Connected Impervious Areas reduce surface runoff volumes, peaks and pollutant loads. The exact performance of this practice depends on the exact nature of the local geology, the type of soils and vegetative cover, and the nature of local climate. Under ideal conditions, surface stormwater runoff from low to medium density single family residential areas can be virtually eliminated for small rainstorms (i.e., storms with less than 13 to 25 mm (0.5 to 1.0 inch) of rainfall).
On the whole, this is a very effective stormwater Best Management Practice (BMP) for low to medium density residential developments and for smaller commercial sites. Minimized Directly Connected Impervious Areas is not a very effective BMP for high density residential developments and high density commercial zones, such as central business districts. This BMP demands that much of the land area of the development have a pervious surface, free of buildings and solid pavement. It may also not be appropriate for use when the general terrain grades are steeper that six percent. With erosion prone soils, Minimized Directly Connected Impervious Areas may require even flatter terrain slopes.
Most sump pump issues can be traced to trouble with the drainage conditions around the outside of the house which result in surface water running down foundation walls or saturating the areas around the foundation and entering the footing tiles. If too much water is allowed to collect in the soil around the foundation, it will naturally end up overwhelming a sump pump.
Swales are used for stormwater routing in subdivisions between houses and in backyards. All new development in Brookstone uses swales (DCIA) along property lines between homes to handle stormwater. These systems can become compromised quickly with changes to the landscaping of individual lots. This generally results in one of two homeowners in a neighborhood with water saturating the areas around the foundation and entering the footing tiles. In the developments since I’ve arrived, the city has taken drainage easements along these areas, so technically we could go in and regrade the area. This is generally very unpopular with most of the neighbors because they have trees, shrubs, retaining walls, storage sheds and fences that would have to be removed. The other problem is that this remedy usually lasts for less than two years before the problem starts all over again.
Generally, the water problem can be corrected by good landscaping or minimal storm piping into the area. The landscaping is the property owner’s responsibility and the storm piping is constructed by the city and usually special assessed to the local owners.
The Brookstone sump pump project began as a special assessment proposal for the residents at 210 Oakbrook Drive. The city put together some designs and cost estimates for the neighbors on this street. Brookstone Homes Inc. was also looking at resolving some drainage issues and met with the city to discuss their problem. During the discussions the city plans were presented and Brookstone indicated a willingness to participate under the conditions of a special assessment.
The city’s standard policy is we don’t special assess any stormwater;
“Storm water sewer costs shall not be special assessed and shall be paid through general revenue funds unless they are constructed and paid for by a subdivider in accordance with a developer’s agreement.”
That was not feasible here and the residents wanted the improvement. Most other assessments are completed with the resident only paying the cost of the material and any contractors.
“When the City authorizes that all or a portion of public improvements, other than storm sewer installation, shall be constructed by City employees using City equipment, the actual costs may be determined to be only the costs of materials and any equipment rentals,”
This started out as a special assessment and I saw no reason to treat it any differently. The Council agreed and approved a motion on July 1, 2008 authorizing the City Manager to take such actions as necessary to implement and administer said policies for the construction of improvements to be constructed in the Brookstone Subdivision.
The city negotiated and signed an agreement with Brookstone on construction and payment conditions for the project. The city recently started construction on the project.
The city’s portion of this project will consist of installing a 12” pipe in the middle of the terrace beginning at the curb inlet on the corner. Six inch pipe will then be stubbed under the sidewalk to the property line which is located 1’ toward the house from the sidewalk. From this point Riverwood will run the connection to your sump pump discharge line.
The installation of the 12” pipe will necessitate the removal of the driveway aprons and the 6” stubs will cause a block or two of sidewalk to be removed. These will be backfilled temporarily, with gravel, to allow access until all pipe has been installed. Once the pipe is complete, a contractor will replace all the concrete removals. Once the concrete is in and Riverwood is finished making the connections, we will return to restore the grass areas we have disturbed, and Riverwood will restore theirs.
The new concrete work will be the most inconvenient for the residents, because it needs to cure for 7 days before vehicles can be allowed to use it. Otherwise, access to driveways will only be denied as we dig through it.
Staff is working with residents on the location of the stubs. The city had painted a pink mark on the sidewalk which appeared to be the ideal location for stubs.