Regulated Washes and Specific Setbacks: Rules for Building Out Your Tucson Lot

Tucson lot buyers can get hung up on the thought of a wash, or arroyo, on a property they’d like to purchase, but when you start the process of buying vacant land with your eyes open, you’ll learn how Pima County regulates land development and how they determine the effects of a wash on a property’s usability.

First, there is an important distinction between regulated and non-regulated washes. Regulated washes must carry a minimum of 100 cubic feet of water (cfs) per second.

Any wash with less flow is labeled non-regulated and is considered minimally invasive to the property. A typical non-regulated wash requires a minimum 25 ft setback. This is an easy guideline to meet when building on an acre lot, for instance.

As washes increase in size, the length of setbacks also increase. The requisite distances between the wash and where you can build your home are calculated by Pima County Flood Control hydrologists and engineers who study the washes’ flow rates.

When regulated washes have flow of 100 cfs or more, setbacks are calculated to 50 and 100 ft. Major washes that carry larger amounts of water can have 250 and 500 ft setbacks and we pay closer attention to properties with these regulations.

When there is a larger wash close to your property and the setback distance is significant, I recommend that clients seek consultation with a hydrologist to conduct an erosion hazard setback reduction study at a cost of $1,000-$3,000. A study will determine the specific features of the wash, including the size, width, clarity and definition of banks, rocky protection, and overall geography of the wash.

For instance, if the vacant lot has a major wash located 40-50 ft below your building site but has a solid, defined wash bank consisting of rocks and boulders, a closer look may provide evidence to decrease the amount of setback required.

Often, the county will determine the setback only by the amount of water flow without investigating the lot’s topography, so a study can produce useful results in your favor without compromising safety.

Desert riparian areas should also be taken into account when buying Tucson lots. Because of the water-rich soil in riparian areas, certain types of plants propagate there, adding necessary biodiversity to the desert. Pima County identifies areas where useful vegetation has developed, rates them with degrees of importance, and imposes different regulation in these areas.

According to these rules, buyers and developers may disturb up to 12,500 sq ft of riparian area without mitigation. In most cases, this is plenty of space to build a house and lay a driveway on the property. Typically, the 12,500 sq ft rule only affects large developments or properties and when these requests are made, Pima County steers people away from riparian areas.

In my next post, I’ll be talking about the best reason to have a wash on your property: flora and fauna! To subscribe to my blog for more updates about vacant land in Tucson, click here. To contact me directly, send me a message here. I look forward to talking lots with you!

Land & Lot Reports


1926 Circle of Excellence for 2020 2017 2019 land report 2020 economic projections 2020 economy 3 Benefits of Planting Native Vegetation aerial allure of land Apache Junction architect area Arizona arizona activities arizona eating Arizona economy arizona events Arizona home owners arizona land report Arizona living arizona real estate arizona realty arizona restaurants arizona summer activities arizona summer events backyard benefits of planting native vegetation best golf courses best golf courses in Arizona best golf courses in Tucson best hikes in tucson best hiking best hiking trail of Tucson best hiking trails best home decor best home details best housing markets best lights best night lights best night time lights best of Tucson best real estate best real estate market best takeout in Tucson Bisbee blueprint blueprints breweries breweries in Tucson Arizona buildable builder building building a home building house built-in desks built-in details built-in shelves burger buying homes buying land buying land in Tucson buying real estate buying real estate in tucson buying Tucson lots carpet change order cinema room classic car construction construction loan construction permit construction plan construction plans cooling coronado forest cost country custom home building custom homes deed restrictions desert garden desert gardening design design guidelines design guidelines for a Subdivision Development diy home improvement dream home dream kitchen easements eatery eating eating in tuscon economic outlook economic projections economics elevation energy efficient events film festivals film festivals in Tucson fireplace flood flood insurance floodplain Flooring food food tours foreclosure geologic language golf courses golf courses in Arizona golf courses in Tucson gps habitat health heated floors heating hidden room hikes hiking historical hobby room holiday events home home blueprint home blueprints home builder Home building home decor home decorations home details home improvement home owners home plan home size house house blueprints house details houseplants housing markets how to buy how to buy land how to make your neighborhood safer hvac industrial style interior design internet internet in Tucson internet providers in Tucson laminate land land parcel land report land use land use in Tucson land zoning living in Tucson loan program lot lots man cave March 2024 land report march land report measurement mexican minimalist modern mortgage movie bluff movie room moving mudroom national park native vegetation neighborhood new home new year night lights non-invasive plants Old West organization packing permit permit needed permits preventing erosion property property in Arizona property in Tucson property listings property report purchasing residential land real estate real estate in Arizona real estate market real estate report realtor tucson recessed light remote work remote work in Arizona remote work in Tucson remote working residential land resolution restaurant riperian riperian habitat rooms run rural Tucson safe neighborhood salad sales salt lamp Scottsdale selling real estate slope spa spa room specialty rooms steak stone style subdivisions Summer summer activities summer events sun exposure takeout Technology theatre things to do in arizona things to do in tucson things to do in tuscon topography travel traveling Tucson Tucson 2020 economy tucson activities Tucson Arizona tucson christmas Tucson economy tucson events Tucson home owners Tucson housing market tucson land tucson land for sale tucson land loans tucson land report Tucson lifestyle Tucson living tucson lot loans tucson lots tucson mountains Tucson national parks tucson real estate Tucson real estate market tucson realty tucson summer tucson summer events Tucson vegetation tuscon land report unusable land Upgrades upgrading your home upgrading your interior useable land vacant land vacant land design guidelines vacant land guidelines vacant land tucson vacant Tucson lots vacation vegetation views vintage walk warranty Wash what to do in Tucson where to eat where to eat in Arizona working in Tucson working remote in Tucson working remotely zip codes zones zoning

Sign Up for News

Sign Up

Featured Listing