JoCo Stormwater Management Tour

March 21, 2013 by /

One of the best ways to learn more about stormwater Best Management Practices is to go see them for yourself– and the next best way is the Riverkeeper’s BMP tour below.

Many BMPs are in publicly accessible locations around Johnson County, making them easy to view. Most cities in JoCo have BMPs, but Lenexa is the leader with over 100. In fact, every new development in Lenexa has a BMP to mitigate the additional runoff caused by buildings, parking lots, and other impermeable surfaces on the site. Many of these BMPs are part of the city’s Rain to Recreation program, which provides hiking trails, fishing, boating, and other recreational opportunities at the BMP. They also enhance plant and wildlife conservation, making them ideal places for bird watchers and outdoor enthusiasts. Lenexa’s innovative approach to stormwater management provides great places to view nature close to home.

Lake Lenexa
Mize Lake
Rain garden
Porous pavement parking lot

 

Filed Under: Johnson County, Storm Water

DeSoto Rain Garden

March 21, 2013 by /

Friends of the Kaw has embarked on a new adventure– we are building a rain garden at the De Soto Riverfest Park boat ramp. Needless to say, this is teaching us a lot about managing stormwater run-off from a hands-on perspective.

Our guide is Ryan Domnick of Low Maintenance Landscape in Lawrence. Ryan told us that rain gardens are a great way to put run-off from parking lots to good use. Using run-off to water a garden rather than polluting our river makes a lot of sense. He explained to us that rain gardens not only reduce the quantity of run-off from impervious surfaces, they also improve water quality.

While water can’t soak into an asphalt or concrete covered surface, it can soak into a lawn…but a lawn can’t soak it all up. What’s different about a rain garden is the top soil is deeper and less compacted, and the plants have really deep roots. As a result, rain gardens soak up thirty percent more water than a typical lawn. But that’s not all…the plants and soil organisms actually help to remove nutrients and other pollutants from the water. The water that percolates out of the rain garden is better for the environment, and our beautiful rain garden will actually help the river while it is delighting us with flowers, butterflies, birds, and wildlife.

We asked Ryan about some of the things we had heard about rain gardens– and he assured us that mosquitoes and weeds are not a problem. If a rain garden is properly designed it drains too fast for mosquitoes to breed (rain gardens are not “swamps” in any sense of the word). And rain gardens can be as neat and attractive as you want– they don’t have to have that “wild” look if you don’t want it. Weeds are controlled by maintaining a think layer of eastern red cedar mulch and some periodic weeding.

Rain gardens sound like a great idea. They reduce the chance that run-off will flood your basement, they are really pretty, and they help the river. Watch our rain garden grow, and check out what we are learning about the entire process of creating a rain garden of our very own.

We want to thank the Johnson County Stormwater Program for funding this project and Low Maintenance Landscape, Inc. for designing and building the project.
Filed Under: JoCo Home Owners/Builders, Johnson County, Storm Water

Developer Information and Resources

March 21, 2013 by /

Johnson County requires developers to follow the Best Management Practices of the APWA/MARC BMP Manual (henceforth APWA/MARC). This means that the basic goal for all developments is to maintain pre-development peak flows, runoff volumes, and water quality. In other words, development should maintain the velocity and quantity of runoff and the amount of pollutants leaving the site, unless the effects are fully considered and documented in the design or unless site conditions apply that require more stringent measures. (APWA/MARC p. ES-1)

In addition to the APWA/MARC BMP Manual, guidance for countywide ordinances can be found on the JoCo Stormwater Management Program website for municipalities, and specific guidance is also given for unincorporated parts of  the county. Specific local ordinances, cost sharing, and other programs have been developed for the following municipalities:

 

Here we provide a brief overview of some of the more common BMP’s that are used in Johnson County to achieve these goals. You can also take a virtual tour of BMP’s in Johnson County and of the Green Infrastructure in Lenexa.

BMPs for Housing and Retail Developments

porouspavementsignPervious Pavements

Pervious pavements allows water to infiltrate the surface layer and enter into a high-void, aggregate, sub-base ayer. The captured water is stored in the sub-base layer until it either infiltrates the underlying soil strata or is routed through an under-drain system to a conventional stormwater conveyance system. (APWA/MARC p. 2-2)

Pervious pavements are an example of structural BMP’s that reduce runoff at the source. There are many different kinds, including interlocking pavers that allow infiltration in spaces filled with pea gravel between the pavers; lattice work with vegetation; and concrete and asphalt that are made to allow water to seep through the surface. In all cases the pavement is underlain with several porous strata that can hold the water while it slowly moves out of the system. You can visit a demonstration project at the Coon Creek Trailhead in Lenexa and learn more about pervious pavement.

bioretention2Bioretention Basins

A common structural BMP for retail and business developments, bioretention basins are small engineered and landscaped basins intended to provide water quality management by filtering stormwater runoff before it is released into stormdrain systems. (APWA/MARC p. 2-1) They are ideal for use in median strips, parking lot islands, and landscaped swales, and are best distributed throughout the development to treat runoff as close to the source as possible.

Effective bioretention cells typically are fairly small, taking up an area equal to about 5% of the total impervious surface of the development. They are easily designed and planned as part of the site’s required open space. In practice, these units are maintained in the same manner as decorative landscaping, which helps to minimize maintenance costs and increase value-added benefits. Implementing this one standardized practice in all developments can minimize design, inspection, and maintenance costs. (APWA/MARC p. 5-2)

bioswaleBioswales

A swale is a depressed area used for stormwater conveyance and/or short term storage (think of it as a modified ditch). The fact that runoff is conveyed through the system rather than being retained within it is what distinguishes a swale from a retention basin or rain garden.

There are several kinds of swales used for stormwater runoff management. A Bioswale is an open vegetated channel with an engineered soil matrix and underdrain system designed to filter the runoff (see photo on left). A Native Vegetation Swale consists of Native grasses and forbes planted in a swale to reduce the velocity of the runoff and promote infiltration. A Turf Grass Swale is planted with turf grass and meant to be used as a substitute for closed drainage systems. Finally, a Wetland Swale is an open vegetated channel without underdrains or a soil matrix designed to filter runoff and remain wet between rain events. (APWA/MARC p. 2-3)

raingardenRain Gardens

Rain gardens are typically used for small areas (less than an acre) and are a good BMP for single family homes. (APWAMARC p. 2-3) Rain gardens can help manage outflow from downspouts or runoff from turfgrass lawns, patios, and driveways. Like Bioretention Basins and Bioswales, they are considered structural BMP’s used for source control.

Rain gardens consist of a depression to retain the runoff, a deep layer of soil with good infiltration properties, and deep rooting plants that are tolerant of periodic high soil moisture. They can significantly reduce excess nutrients and sediment in runoff and, if they are sufficient in number, can be an important component of reducing runoff in a watershed. Typically the home owner will maintain rain gardens on their property. When they are first installed (the one on the left is newly planted), they should be weeded weekly. Never use fertilizer on or near a rain garden. After plants are well established, leave the dead vegetation standing over the winter to provide bird habitat, then remove it in the spring by mowing or burning (if allowed). (APWA/MARC pp. 8-1 to 8-4)  Click here for information about building Rain Gardens.

vegwetlandVegetated Wetlands

A wetland is area that is permanently wet or periodically flooded by surface or groundwater and has developed hydric soil properties that support vegetation growth under saturated soil conditions. It may have been engineered with adequate capacity to detain large storm flows. (APWA/MARC p. 2-1)

A distinction must be made between using a constructed wetland for stormwater management and diverting stormwater into a natural wetland; natural wetlands and streams are protected by the Clean Water Act and activities that alter or fill them are regulated by state and federal agencies (for an overview go to the KDHE website). Natural wetlands should be protected because they are important for reducing flooding and improving water quality, as well as providing crucial habitat for many species of plants and animals. Constructed wetlands, in contrast, are used for receiving and pretreating stormwater runoff from developments.

An Extended Detention Wetland is a constructed basin that has a permanent pool of water throughout the growing season. Runoff is detained for a 40-hour period. They are relatively shallow (approximately 18 inches maximum depth) and are heavily vegetated. Both the rooted plants and microbial processes in the soil remove nutrients and many types of pollutants, resulting in a significant improvement in water quality. Extended Detention Wetlands are among the most effective stormwater practices in terms of pollutant removal, and they also offer aesthetic value, especially for their wildlife habitat. (APWA/MARC p. 8-40)

ripariansmallRiparian Corridors and Stream Buffers

Riparian corridors are trips of herbaceous and woody vegetation located parallel to perennial and intermittent streams and adjacent to open bodies of water. They capture sediment and other pollutants in surface runoff water before these can enter the adjoining surface waterbody. A stream buffer is an area defined by regulatory agencies or municipalities for the protection of riparian corridors and
floodplains. (APWA/MARC p. 2-3)

An undisturbed riparian corridor in northeastern Kansas will be heavily vegetated, typically with an under layer of grasses and forbs, an intermediate layer of bushes and young trees, and a mixed forest with trees of different ages and species. Riparian corridors are an integral part of the stream system. They provide shade that lowers water temperature; leaf fall and insects that form an important component of the stream food web; deep roots that hold soil in place and absorb nutrients and other pollutants; and dense vegetation that slows the overland flow of runoff, allowing suspended sediment to settle out before reaching the stream. Riparian corridors with native vegetation not only provide many important ecosystem services, they can also provide beautiful locations for recreational trails, as can be seen in Kill Creek Park and Mill Creek Streamway Park

Preserving existing vegetation along streambanks is a non-structural BMP that can be a very cost effective way of reducing both pollution from stormwater runoff and flood hazard to residential and commercial developments. APWA recommends creating community-wide stream buffer systems through the enactment of stream setback ordinances. For example, preserving a 100-foot riparian buffer in a watershed of 5,000 acres (less than 5% of the land in the watershed) can yield disproportionate benefits; not only does it reduce adverse impacts from stormwater runoff, it can also provide significant financial returns to communities by increasing home values through the aesthetic and recreational opportunities that it provides. (APWA/MARC pp. 7-12 to 7-14) You can find the EPA model setback ordinance as well as the ordinances adopted by the City of Lenexa and Overland Park on the MARC website.

MizeLakeTreatment Train

The treatment train refers to the series of BMPs (or other treatments) used to achieve biological and physical treatment efficiencies necessary for removing pollutants from stormwater or other wastewater flows. (APWA/MARC p. 2-3)

Mize Lake is an example of a complex series of structural BMPs used for managing runoff from a large area. It is a seven-acre lake with three sediment forebays, three wetlands, and two bioretention cells (click here for more information).

Many Treatment Trains combine both structural and non-structural BMP’s to increase infiltration and successively treat the water as it passes through the system. Large scale systems like this are used to manage stormwater that is in excess of that which is captured and treated at the source by BMP’s like the Bioswales or Bioretention Basins described above. (APWA/MARC 3-4)

The City of Lenexa has developed a Rain to Recreation program that utilizes stormwater management BMP’s like Mize Lake and Lake Lenexa as parks and recreational facilities. By preserving Native vegetation, providing Riparian Buffers and other non-structural approaches these BMP Treatment Trains/recreational facilities maintain a natural character that provides both aesthetic value and important wildlife habitat.

silt fenceConstruction Site BMP’s

Best Management Practices during construction not only significantly reduce the negative impacts of runoff during the construction phase, but can also have long-lasting positive effects on post-construction stormwater management. Obvious design elements like the practices listed above are all important, but so is the way in which soil and vegetation are treated during the construction process. Plants that are native to Kansas typically have deep roots that help stormwater penetrate deeply into the soil and are well adapted to the Kansas climate, allowing them to thrive without fertilizer, pesticides or regular watering. Maintaining native vegetation, especially around waterways, can be a cost effective way to reduce runoff. Soil preservation and restoration measures are also important; compacted soils have poor infiltration capacity. In contrast, soils that have developed in areas with native  vegetation have deep, humus-rich layers with excellent infiltration capacity. Wherever possible these soils should be preserved or restored. (APWA / MARC 5-39 to 5-40)

 

Westwood sign

Filed Under: JoCo Home Owners/Builders, Johnson County, Storm Water

Home Owner Tips and Resources

March 21, 2013 by /

Tips for Reducing Runoff and Pollutants from your Home and Lawn

rainbarrelInstall rain barrels.

Your roof collects a lot of water during a rainstorm, so why not use it in your garden rather than sending it down a storm drain? You can find rain barrels at many hardware stores, and if you are handy you can make one yourself.

algaeReduce your use of yard chemicals and don’t apply fertilizers or pesticides if you know it’s going to rain.

When nutrients from fertilizer are washed into a stream they cause algal blooms, which are not only bad for the stream, they are also unattractive and smell bad. You can test your soil to see if you even need to add fertilizer. And needless to say, pesticides are definitely not good for streams. A healthy yard won’t need as many chemicals, so its a win-win situation.

raingardensmallPlant rain gardens.

Rain gardens are a beautiful addition to your yard and can retain a lot of stormwater runoff. Think about planting rain gardens to catch water running off your lawn. You can see what one looks like by visiting the Friends of the Kaw’s rain garden demonstration at the De Soto Riverfest Park boat ramp or going on the JoCo BMP tour.

prairieflowersmallUse native plants.

Native plants need less watering, fewer pesticides and herbicides, and grow deeper roots to catch runoff.  To identify appropriate natives for use in our area the  Kansas Native Plants Society,  Grow Native, and   Kansas Native Plants websites all provide online resources.

bufferDon’t mow within 10 to 25 feet from the edge of a stream.

Leave a buffer. This will reduce the amount of runoff entering the stream. Native grasses, bushes and trees act as a filter to stop sediment, trash, and pollutants from entering the stream. Plants also absorb excess nutrients in runoff, preventing harmful algal blooms in the stream.

vegbankBushes and trees along the bank are the best way to prevent erosion.

Leaving a buffer is the most effective way to stop erosion, since bushes and trees have stronger, deeper roots that hold the bank in place. Concrete rubble, tires, trash—these are not good for the stream, they don’t work to prevent erosion, and they are ugly. On top of that, they are illegal. Municipalities in Johnson County have developed their own regulations for streambank stabilization (Overland Park’s regulations can be found here), so make sure you check with your local government before beginning a stabilization project.

Pavers_smallReduce the area covered by hard surfaces.

If you have a walkway that is seldom used, consider replacing hard surfaces like concrete, brick or asphalt with a pervious surface like mulch, gravel, or pervious pavers – learn more about pervious pavement. You can also visit local projects in the JoCo BMP Tour.

drainDon’t create unnecessary runoff.

Sweep or blow your driveway rather than washing it off with a hose. This will reduce the amount of runoff that goes into storm drains. And use commercial car washes, which are required to manage their wastewater with sand-oil filters, rather than washing your car at home.

nodumpingNever pour oil or other chemicals down storm drains.

What you pour onto your driveway, roadway, or directly into storm drains.  What goes down the drain goes to the river, untreated, and will contaminate the water we drink and the fish we eat. And remember that oil and water don’t mix—please recycle your used oil.

tsosa

Clean up after your pets.

It is amazing how much pet waste can accumulate in your neighborhood. By picking it up you can reduce the amount that gets washed into streams during storms, and that reduces the amount of bacteria and nutrients that wash into the river. Don’t fancy the idea of scooping poop on a regular basis? A directory of businesses that manage pet wastes, or “commercial pooper-scoopers,” can be found online.

Filed Under: JoCo Home Owners/Builders, Johnson County, Storm Water

Agricultural Producer Information and Resources

March 20, 2013 by /
Johnson County is an important agricultural producer with almost 45,000 acres of soybeans, corn, wheat and sorghum and almost 24,000 acres of hayland. In addition to crops, there are also enough cows in the area to populate a small city. Fertilizers and chemicals used in agriculture and management of animal waste and other by-products all substantially impact the Kansas River.

There are a number of programs that help farmers by providing guidance – and in some cases cost share options – on projects that help reduce pollution in stormwater runoff. These include:

Best Management Practices for Agricultural Producers

Best Management Practices are also good business practice. Practices that reduce runoff can also increase profitability by decreasing erosion and costs by reducing the need for fertilizer and chemical application, improving soil and water, and improving livestock productivity. Consider the following BMPs for your farm.

aerial.viewConduct a Farm Assessment

The River Friendly Farms Environmental Assessment at The Kansas Rural Center can provide help.

 

Plan and Implement Extended Legume-Based Crop Rotations

A study conducted in the Lower Kansas River watershed by K-State researchers has found that reducing tillage was similar in production costs per acre but substantially decreased soil erosion, nitrogen and phosphorous loss.

Use Cover Crops

According to the Kansas Wheat Association high residue cropping systems and conversion to no-till or minimum till with a planned crop rotation can reduce the need for fertilizer, improve soil moisture, and reduce erosion from wind and rain.

Buffer strips, Riparian Filter Strips, and Field Grass Filter Strips: 

The NRCS considers buffers a win-win-win strategy because they are economically viable when developed with federal and state incentives; help farmers to meet federal, state, and county regulations; improve habitat for wildlife and game species; and reduce flooding. All that while reducing sediment, nutrients, pathogens and ag chemicals entering streams. You can get assistance with economic incentives and project planning from your local NRCS office. These programs include:

corn.cliffStreambank Stabilization and Erosion Control

Streambank erosion is a major concern in Kansas because it is a leading cause of reservoir sedimentation. Buffer strips can significantly reduce erosion. 

 

herefordsLivestock Management

Use livestock management systems that reduce confinement feeding and potential pollution including:

brown.cowsDevelop livestock waste management systems that limit potential pollution including:
Filed Under: Johnson County, Storm Water

Managing Stormwater

March 20, 2013 by /

Johnson County is the fastest growing area in the entire Kansas River watershed. Rapid growth can result in many challenges, not least of which is what to do with the extra runoff that accompanies urban and suburban development. To address this problem, Johnson County instituted a 1/10th cent sales tax to fund the Johnson County Stormwater Management Program. This forward-looking approach has made Johnson County a leader in the innovative management of stormwater, and has even managed to change a problem into an asset with programs like the City of Lenexa’s Rain to Recreation program.

Click here to view a map of Johnson County Stormwater Management Resources. 

What causes stormwater runoff?

Impervious surfaces in the U.S. Source: Rivers in Crisis, riverthreat.net

Impervious surfaces in the U.S. Source: Rivers in Crisis, riverthreat.net

Housing and retail developments are full of impermeable surfaces such as roofs, sidewalks, and roads. While undeveloped land has plants and thick topsoil to absorb rain during a Kansas thunderstorm, these impermeable surfaces absorb little or no water . The increased runoff from impermeable surfaces can cause localized flooding, damage homes, and affect the quality of our drinking water.

Don’t think runoff adds up to much? Consider this:  With only one inch of rain a house with a 2000-square foot roof will have over a thousand gallons of water running off of it. That’s a lot of water, especially if that water is coming out of a neighbor’s downspout heading straight for your property!

Where does stormwater runoff in Johnson County go?

stormsewerStormwater that enters storm drains on the streets and in the parking lots of Johnson County is collected into a storm sewer system, which eventually discharges into the Kansas River system or possibly the Missouri or Marais des Cygnes Rivers, depending on where in the county you live.

What are the consequences of increasing stormwater runoff?

One of the biggest reasons stormwater must be carefully managed is to reduce the risk of dangerous flooding, but there are other important reasons as well – like safe drinking water. Stormwater runoff entering storm drains eventually makes its way to the streams, reservoirs and rivers from which many communities obtain their drinking water. When these water sources are contaminated by pollutants carried by runoff those pollutants have to be removed by water treatment plants. The resources required to do this can potentially increase your water bill.

What causes pollution in runoff?

Stormwater runoff carries fertilizer, herbicides, pesticides, and pet waste with it – all of which can cause health and safety problems. Fertilizers increase nutrients in reservoirs, leading to algal blooms and “skunky” tasting water – an expensive water treatment problem for municipalities. Pesticides and herbicides create problems not only in water quality but also with the animals living in that water. For many years a fish consumption advisory issued by the Kansas Department of Health and Environment was in place between Lawrence and Eudora due to contamination by Chlordane, a pesticide used to prevent termites. Though the advisory has been lifted, a PCB advisory is still in place. (Click here for more information about current fish advisories in the Kansas River.)

What is sedimentation, and why is it a problem?

BJO 1smallSmall particles of soil and other solid matter – or sediment – carried by rainwater passes through streams and can settle in reservoirs. Reservoirs serve to hold back stormwater and reduce the amount of flooding in downstream communities. Some also provide drinking water for nearby communities. As sediment builds, the capacity of a reservoir is reduced, resulting in less available drinking water and a reduced ability to hold back flood waters. We have recently found that sedimentation is occurring in the Clinton, Perry and Tuttle Creek Reservoirs.

The Kansas Water Office funds many projects to reduce sedimentation in Kansas streams and rivers, and hence in the reservoirs. These projects attempt to cut off the problem at the source– stormwater runoff. Poor construction practices can greatly increase the amount of sediment in runoff.  This is one of the reasons why the Johnson County Stormwater Management Program has adopted a series of Best Management Practices for Home Builders.

How is stormwater regulated?

Water that flows out of pipes into the river and its tributaries is considered a point source and is regulated under the National Pollution Discharge Elimination System (NPDES). Permits are issued by the Kansas Department of Health and Environment (KDHE) under authority delegated to it by the Environmental Protection Agency (EPA) to regulate water quality of stormwater discharges. Cities in Johnson County are required by the Stormwater Management Plan to obtain NPDES permits and regulate the amount of runoff (water quantity) and the amount of pollutants in runoff (water quality) that is discharged from their storm sewers into the Kansas River and its tributaries. These permits specify things like how much sediment, nutrients from fertilizers, bacteria, pesticides, and other pollutants can be in the water when it is finally discharged to the river.

You can help!

To learn how you can reduce stormwater runoff and improve the quality of water running off your home and yard visit our Best Management Practices for Homeowners page. You’ll also find helpful information in our Resources section. Working together we can protect our homes from flooding and ensure that we always have clean and abundant drinking water supplies.

Is my home in the Kansas River Watershed?

A large part of Johnson County falls in the Lower Kansas River Watershed. In fact, the northern border of the county is created by the Kansas River, which separates Johnson County from Wyandotte and Leavenworth Counties. If you live in the Johnson County portion of the Kansas River watershed your activities have a huge impact on the Kaw. Click the map below to visit the Johnson County Automated Mapping Information System and enter your address to see if your home is located in the watershed.

 

 

 

Filed Under: Johnson County, Storm Water

Stormwater Poster

March 20, 2013 by /
Filed Under: Storm Water

Stormwater Overview

March 13, 2013 by /

EPA website with additional resources

Effectively managing stormwater is important to all of us. Poorly managed stormwater runoff causes flash floods and accumulates in low-lying areas (like your basement).

Roofs, driveways, sidewalks, roads– housing developments are full of surfaces that do not absorb water. Poor construction practices can

greatly increase the amount of sediment in runoff. This is important, since sedimentation is a major problem in Tuttle Creek, Milford, Perry and Clinton flood control reservoirs on the Kansas River system.

Stormwater washes fertilizer, herbicides, pesticides, and animal waste off lawns and farmland. It carries pollutants into lakes and rivers used for drinking water supplies. These increase nutrients in reservoirs, leading to algal blooms and “skunky” tasting water. Some severe algal blooms can become toxic.

In contrast, the plants and soils of a natural prairie absorb much (if not all) of the rain during a Kansas thunderstorm. And stormwater that is absorbed by soil and plants is actually cleaned of nutrients and many other pollutants. This is why planting buffer strips and rain gardens not only reduces the amount of stormwater runoff, it improves the quality of stormwater runoff that flows off the land and into the river.

Rivers all over the nation are suffering from pollution from stormwater runoff. The map below highlights areas where water quality is degraded by runoff because of the large proportion of the watershed that is covered in impervious surfaces (such as asphalt, concrete, and roofing materials that are impervious to water). In Kansas this is especially true in the Kansas City Metropolitan Area, Johnson County, Topeka and Wichita.

 

This website provides solutions to the problems caused by stormwater runoff in the Kansas River watershed.

Filed Under: Storm Water
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